Ozcan v Macarthur Disability Services Limited - [2020] NSWWCCPD 21

DETERMINATION OF APPEAL AGAINST A DECISION OF THE COMMISSION CONSTITUTED BY AN ARBITRATOR
CITATION:	Ozcan v Macarthur Disability Services Limited [2020] NSWWCCPD 21
APPELLANT:	Nuray Ozcan
RESPONDENT:	Macarthur Disability Services Limited
INSURER:	AAI limited t/as GIO – Agent for the Workers Compensation Nominal Insurer
FILE NUMBER:	A1-691/19
ARBITRATOR:	Mr J Wynyard
DATE OF ARBITRATOR’S DECISION:	23 September 2019
DATE OF APPEAL DECISION:	21 April 2020
SUBJECT MATTER OF DECISION:	Aggregation of impairment – application of common law principles, whether the impairment “results from” the injury – Le Twins Pty Ltd v Luo [2019] NSWWCCPD 52, Murphy v Allity Management Services Pty Ltd [2015] NSWWCCPD 49, Nicol v Macquarie University [2018] NSWSC 530, Johnson v NSW Workers Compensation Commission [2019] NSWSC 347, Government Insurance Office of NSW v Aboushadi [1999] NSWCA 396, considered; State Government Insurance Commission v Oakley (1990) 10 MVR 570; [1990] Aust Torts Reports 81-003, Secretary, New South Wales Department of Education v Johnson [2019] NSWCA 321 considered and applied; application of s 322 of the Workplace Injury Management and Workers Compensation Act 1998 – Department ofJuvenile Justice v Edmed [2008] NSWWCCPD 6; 7 DDCR 288 applied
PRESIDENTIAL MEMBER:	Deputy President Elizabeth Wood
HEARING:	On the papers
REPRESENTATION:	Appellant:
Mr B McManamey, counsel
Brydens Lawyers Pty Ltd
Respondent:
Mr S Grant, counsel
Hicksons Lawyers
ORDERS MADE ON APPEAL:	1. Paragraph one of the Certificate of Determination dated 23 September 2019 is revoked and the following order is made in its place: (a) The respondent is to pay the applicant $17,902.50 in respect of 12% whole person impairment of the lumbar spine and the thoracic spine (including a 5% uplift) pursuant to s 66 of the Workers Compensation Act 1987. 2. The Certificate of Determination is otherwise confirmed.

INTRODUCTION AND BACKGROUND

Ms Nuray Ozcan (the appellant) suffered a number of injuries in the course of her employment with Macarthur Disability Services Limited (the respondent). The injuries involved the lumbar spine, the thoracic spine, cervical spine, right shoulder and consequential conditions including the upper digestive system. The appellant also suffered a further cervical spine injury on 28 January 2013, which occurred at home and consequently was not the subject of these proceedings.
The appellant brought proceedings in the Commission for lump sum entitlements pursuant to s 66 of the Workers Compensation Act 1987 (the 1987 Act) together with a claim for weekly payments and treatment expenses pursuant to s 60 of the 1987 Act. By consent, the lump sum claim was referred by the Arbitrator, Mr C Burge, to an approved medical specialist (AMS) in the following terms:
“Date of Injury 1:               14 November 2011
Body part/s referred:        Lumbar Spine, Thoracic Spine, Cervical Spine, Right Upper Extremity (shoulder), Upper Digestive Tract
Method of assessment:     Whole Person Impairment
Date of Injury 2:                3 May 2012
Body part/s referred:        Lumbar Spine, Thoracic Spine, Upper Digestive Tract
Method of assessment:     Whole Person Impairment
Date of Injury 3:                26 September 2012
Body part/s referred:        Lumbar Spine, Thoracic Spine, Upper Digestive Tract
Method of assessment:     Whole Person Impairment
The AMS is to be directed to apportion the impairment suffered by the applicant to the lumbar spine, thoracic spine and upper digestive tract resulting from the three separate dates of injury.
The AMS is to be advised that the referral of the upper digestive tract is on the basis that the parties agree that there are symptoms causally related to the accepted injuries, but that the AMS should determine what pathology, if any, relates to the accepted injuries.”[1]
[1] Certificate of Determination (COD) – Consent Orders dated 17 April 2019.
The AMS, Dr Neil Berry, issued a Medical Assessment Certificate dated 17 June 2019, in which he opined that the upper digestive tract symptoms were not ratable. He provided the following assessments:
(a)    cervical spine: 0% whole person impairment (WPI);
(b)    right upper extremity: 3% WPI as a result of the injury on 14 November 2011;
(c)    thoracic spine: 5% WPI as a result of injuries on 14 November 2011, 3 May 2012 and 26 September 2012;
(d)    lumbar spine (including allowance for the effect of the injuries on activities of daily living): 7% WPI resulting from injuries on 14 November 2011, 3 May 2012 and 26 September 2012 and,
(e)    Total WPI: 15%.
As requested, the AMS apportioned the WPI between each injury. In respect of the spinal injuries, he indicated that the total impairment was 12% WPI, of which 4% WPI was attributable to each injury. That finding resulted in the following assessments for each injury:
(a)    7% WPI (3% in respect of the right shoulder and 4% in respect of the thoracic and lumbar spine) as a result of the injury on 14 November 2011;
(b)    4% WPI (thoracic and lumbar spine) as a result of the second injury, and
(c)    4% WPI (thoracic and lumbar spine) as a result of the third injury.
The matter was then referred to a different Arbitrator, Mr J Wynyard, who issued oral consent orders in respect of the claim for weekly payments and noted that the parties agreed to a general order for the payments of s 60 expenses. The Arbitrator listed the matter for arbitration in order to hear submissions and determine the remaining issue between the parties. That issue was whether the appellant was entitled to the combined value of the total WPI assessed by the AMS as 15%.

ON THE PAPERS

Section 354(6) of the Workplace Injury Management and Workers Compensation Act 1998 (the 1998 Act) provides:
“(6) If the Commission is satisfied that sufficient information has been supplied to it in connection with proceedings, the Commission may exercise functions under this Act without holding any conference or formal hearing.”
I have had regard to Practice Directions Nos 1 and 6, the documents that are before me and the submissions by the parties that the appeal can proceed to be determined on the basis of these documents. I am satisfied that I have sufficient information to proceed ‘on the papers’ without holding any conference or formal hearing and that this is the appropriate course in the circumstances.

THRESHOLD MATTERS

There is no dispute between the parties that the threshold requirements as to quantum and time pursuant to ss 352(3) and 352(4) of the 1998 Act have been met.

THE EVIDENCE

The referral to the AMS and the AMS’s assessment and apportionment of the losses is discussed above. Given the terms of the referral of the injuries to the thoracic spine, lumbar spine, right upper extremity, and the consent orders entered into by the parties, the following summary of the evidence is limited to a review of the evidence that pertains to the question of the connection between the injury on 14 November 2011 and the appellant’s ultimate WPI.

The appellant’s statement evidence

The appellant provided a statement dated 12 July 2018.[2]
[2] Application to Resolve a Dispute (ARD), pp 1–7.
The appellant described the injury on 14 November 2011 and complained that in the incident, she felt immediate pain in her right buttock and lower back as well as a burning sensation in her neck. She stated that she also suffered severe pain in her right shoulder. The appellant did not complain in her statement of pain in the thoracic area.
The appellant said that she suffered the further injury on 2 May 2012 (the injury referred to in the referral to the AMS as 3 May 2012), in which she again experienced right buttock pain and a “sharp pinching sensation”[3] in her lower back and upper thoracic spine. The appellant referred to the third injury on 26 September 2012, in which she straightened up from a bending position and experienced a cracking sensation in her lower back and increased back pain. She also recorded numbness and tingling pain in her upper thoracic spine.
[3] Appellant’s statement, ARD pp 1–7, [17].

The appellant’s medical evidence

There was a bundle of WorkCover Certificates of Incapacity in evidence.[4] The certificates, which were predominantly issued by the appellant’s treating general practitioner, Dr Kenneth McCroary, covered the period between 16 June 2015 and 15 January 2018. All certificates referred to the date of injury as 14 November 2011 and diagnosed L5/S1 disc dehydration, lumbar spine tear and C5/6 disc protrusion with compression of the C6 nerve root in the neck.
[4] ARD, pp 119–220.
Dr Balsam Darwish, neurosurgeon, was the appellant’s treating specialist and provided a comprehensive medical report dated 4 February 2018 at the request of the appellant’s legal representatives.[5] He first consulted with the appellant on 23 October 2012. Dr Darwish recorded that the appellant first suffered injury on 14 November 2011, in which she experienced low back pain. Dr Darwish noted the two subsequent injuries and that at a consultation on 3 December 2012, the appellant also complained of neck pain. Dr Darwish reported that there were a number of subsequent consultations between 7 May 2013 and 11 June 2014 during which the appellant also complained of pain in the interscapular region. Dr Darwish reported on the radiological investigations, which included an MRI scan dated 4 June 2014 that showed a small disc bulge at T7/8 level of the thoracic spine. Dr Darwish commented that the radiological investigations demonstrated changes in the cervical, thoracic and lumbosacral spine which were, in his view, most likely degenerative in nature but aggravated by the injuries in November 2011 and September 2012.
[5] ARD, pp 99–102.
The appellant’s legal representatives qualified Dr Sikander Khan, general surgeon, to provide a medico-legal opinion. Dr Khan provided a report dated 15 February 2017.[6] Dr Khan took the history that the appellant suffered injury on 14 November 2011 in which her whole body twisted, causing pain in the right buttock and lower back and a burning sensation in her neck. She also had symptoms in her right shoulder. Dr Khan noted further injury to the appellant’s lumbar spine in the two subsequent injuries.
[6] ARD, pp 88–98.
On examination Dr Khan relevantly noted the appellant complained of numbness and pain in the thoracic spine and under the shoulder blades, as well as mid back pain. Dr Khan reviewed the MRI investigations dated 4 June 2014 and 1 February 2016 and noted that both investigations disclosed a posterocentral protrusion at the T7/8 level of the thoracic spine.
In respect of the thoracic spine, Dr Khan diagnosed a musculoligamentous injury resulting from the injury on 14 November 2011. Addressing the question of causation, Dr Khan said as follows:
“I note that following the initial injury of 14 November 2011, she has suffered further aggravations and injuries in the subsequent incidents of 3 May 2012, 26 September 2012 and 28 January 2013 along with the subsequent nature and conditions of her employment. It is therefore my opinion that apart from the frank injury of 14 November 2011, the subsequent general nature and conditions of her employment with the episodes of aggravation sustained on the dates mentioned above has contributed further to her initial injury of 14 November 201[1].”[7]
[7] ARD, p 96.
Dr Khan provided a further report dated 13 June 2018.[8] He confirmed the history and findings reported by him in his earlier report. Dr Khan was of the opinion that the appellant’s condition was caused by the frank injury on 14 November 2011, which was subsequently aggravated by the various later injuries and the nature of the appellant’s work. Dr Khan assessed the WPI of the thoracic spine as a result of injury to be 5% and assessed the appellant’s total impairment as 24% WPI.
[8] ARD, pp 108–118.

The respondent’s medical evidence

The respondent qualified Dr Richard Powell, orthopaedic surgeon, to provide a medico-legal opinion. He provided a report dated 4 December 2018.[9] Dr Powell took a history of the three injuries but did not refer at all to a thoracic injury. Dr Powell noted, however, that the appellant’s complaints included pain between the shoulder blades that extended to the lumbar spine, where the pain was more severe. Dr Powell reviewed the radiological evidence, that included an MRI scan dated 15 July 2013 which disclosed a minor disc protrusion at the T7/8 level of the thoracic spine. He was of the view that there was no significant change demonstrated on the later MRI scans dated 4 June 2014 and 1 February 2016. Dr Powell diagnosed musculoligamentous injury in the thoracolumbar spine in association with degenerative disc pathology at the T7/8 level.
[9] Reply to ARD (Reply), pp 57–69.
Dr Powell was asked to provide an opinion as to whether the appellant suffered injuries to the cervical, thoracic and lumbar spines and/or right shoulder as a result of the injuries on 14 November 2011, 3 May 2012 and 26 September 2012, as well as 28 January 2013. Dr Powell formed the view that based on the available information, he believed that it was reasonable to conclude that the appellant suffered injuries (including to the thoracic spine), as a result of a series of frank injuries in the course of her employment.
Dr Powell concluded that the mechanism of injury described by the appellant was sufficient to have caused the injuries she sustained. Dr Powell further concluded that he could find no evidence for assessable impairment of the thoracic spine.

The Medical Assessment Certificate

Relevantly, the history recorded by the AMS in the Medical Assessment Certificate (MAC) was that in the incident on 14 November 2011, the appellant twisted her whole spine, but the history did not record complaints of thoracic symptoms flowing from that incident. The AMS summarised the injuries as:
(a)    injury to the spine and right shoulder on 14 November 2011, together with digestive tract disturbance;
(b)    injury on 3 May 2012 to the thoracic and lumbar spine and digestive tract, and
(c)    further injury to the thoracic and lumbar spine on 26 September 2012.
As was reflected in the MAC, the AMS apportioned the WPI of the thoracic and lumbar spine equally between the three injuries.
The balance of the medical evidence did not either take a history of the thoracic injury or provide a relevant opinion, with the exception of Dr Vidyasagar Casikar, neurosurgeon, who was of the view that the appellant had fully recovered from all of her injuries.[10]
[10] Report dated 27 February 2013, Reply, pp 26–32.

THE ARBITRATOR’S REASONS

The Arbitrator noted the procedural history of the matter and the issue that remained to be determined by him. He further noted that the appellant submitted that she was not seeking to have aggregated the separate assessments made by the AMS. Rather, she was seeking a finding that each injury had been materially contributed to by the original injury on 14 November 2011 and that the 15% WPI was independent of the principles regarding aggregation of the losses.
The Arbitrator recorded in detail the appellant’s submissions, which referred to s 322 of the 1998 Act (the provision dealing with the aggregation of impairments) and s 323 of the 1998 Act (deduction of any percentage WPI for previous injury). He noted the appellant relied upon Kooragang Cement Pty Limited v Bates[11] as support for the notion that subsequent injurious events which materially contributed to the initial injury did not absolve the party liable for the first injury from the further liability. The Arbitrator also summarised the respondent’s submissions that, on the basis of the Presidential decision in Department ofJuvenile Justice v Edmed,[12] as well as a number of decisions of Commission arbitrators,[13] it was not possible to combine the later assessments with the assessment for the first injury because the pathology of each injury was not the same.
[11] (1994) 35 NSWLR 452; 10 NSWCCR 796 (Kooragang).
[12] [2008] NSWWCCPD 6; 7 DDCR 288 (Edmed).
[13] Warwar v Speedy Courier (Australia) Pty Ltd [2010] NSWWCCPD 92 (Warwar); Mordaunt v Qantas Airways Limited [2015] NSWWCC 143 (Mordaunt); Stagg v Department of Education and Communities [2014] NSWWCC 441 (Stagg); Hafizi v Rack Technologies Pty Ltd [2018] NSWWCC 119 (Hafizi).
The Arbitrator reproduced various sections of the 1987 and 1998 Acts, which, where relevant, are reproduced below.
The Arbitrator referred to and quoted from Edmed[14] in which Roche DP determined that, for the purposes of aggregating the percentage impairments from different events, the pathology in each injury must be identical.
[14] Edmed, [25]–[27].
The Arbitrator noted the appellant’s submission that the principles in Edmed did not apply in the circumstances of the appellant’s case and that Edmed could be distinguished on the basis of common law principles in relation to the concept of “material contribution.” The Arbitrator referred to the appellant’s submission that if it could be shown that the injury on 14 November 2011 materially contributed to the impairment caused by subsequent events, then the total WPI was payable. It was not necessary to consider the provisions of s 322 of the 1998 Act. The Arbitrator noted that the appellant relied on Murphy v Allity Management Services Pty Ltd[15] for that proposition, in which case the argument was that the worker had not established the proposed surgery was reasonably necessary prior to the occurrence of a non-work related injury. The Arbitrator quoted passages from that decision[16] and referred to the appellant’s argument that the injury on 14 November 2011 was responsible for the subsequent accidents and there was no novus actus interveniens because the AMS had found them all to be causally linked and apportioned accordingly.
[15] [2015] NSWWCCPD 49 (Murphy).
[16] Murphy, [57]–[58].
The Arbitrator observed, however, that whilst the principle of material contribution will establish a causal connection between two injurious events, it does not concern the calculation of whole person impairment itself.
The Arbitrator noted that the appellant also relied on the Supreme Court decisions of Johnson v NSW Workers Compensation Commission[17] and Nicol v Macquarie University.[18] The Arbitrator observed that in those cases, there was no dispute about the pathology involved, namely the psychological condition, so that s 322 of the 1998 Act had no application. The Arbitrator said that the provisions of Pt 7 of Ch 7 of the 1998 Act are concerned only with medical assessments of WPI for the purpose of payment of a lump sum and the opinion of an AMS on other issues is not binding. The Arbitrator said that it followed that he did not agree with the appellant that the circumstances of this case did not conflict with the principles discussed in Edmed. He said that Edmed established that the impairments caused by the different injurious events would have to result from the same pathology for the appellant to be assessed together in accordance with s 322(2) of the 1998 Act. The Arbitrator referred to the appellant’s submissions that this case was governed by s 322(3) of the 1998 Act and not s 322(2), noting that all s 322(3) required was the appellant to show that the different pathologies arose from the same event. The Arbitrator observed that the parties had accepted that there was a causal link between the injury on 14 November 2011 and subsequent aggravations to the lumbar and thoracic spine, so that it was not necessary for the appellant to show that the pathologies involved in the subsequent events were the same.
[17] [2019] NSWSC 347 (Johnson No 1).
[18] [2018] NSWSC 530 (Nicol).
The Arbitrator considered that there were some difficulties with the appellant’s approach. The Arbitrator pointed out that the AMS is bound by the terms of the referral, and in this case, the AMS was not asked to combine the assessments he made in each of the matters referred to him. Secondly, the Arbitrator observed that each matter that was referred to the AMS was described as a separate injury and thirdly, the AMS was directed to apportion the impairment between the injuries. The Arbitrator said that it followed that the opinion of the AMS as to the combined value of the impairments was beyond the matters remitted to him, was therefore not binding, and did not reflect the intention of the parties when the consent orders were made.

The Arbitrator was satisfied that the finding by the AMS conclusively proved that the appellant suffered from the impairments ascribed to each body part and that each injury contributed to the WPI of the thoracic and lumbar spine in the proportion of 4% WPI. The Arbitrator said that the AMS was obliged to assess the degree of permanent impairment of the appellant as a result of three injuries and those assessments were conclusively presumed to be correct, so that it was only those assessments that were to be the subject of his orders.
The Arbitrator observed that the matter was referred to the AMS on the basis of the consent orders entered into by the parties and that those consent orders were reflected in the orders made by the previous Arbitrator. The Arbitrator further observed that the appellant relied on the three dates of injury in Part 4 of the Application to Resolve a Dispute, but that in part 5.6 the appellant relied solely on 14 November 2011 as the date of injury. The Arbitrator said that, looking at it objectively, the intention of the parties in entering into the agreement was that the AMS was asked to assess three dates of injury and by inference, the parties decided not to refer the matter on the basis of only one date of injury.
The Arbitrator said that, notwithstanding that referral, the appellant’s argument was precisely the proposition that she suffered more than one pathology as a result of one injury, that is, the injury on 14 November 2011.
The Arbitrator considered that the difficulty with the appellant’s argument that Edmed was only concerned with s 322(2) of the 1998 Act was that the ratio decidendi in Edmed was not that restricted. The Arbitrator indicated that while Roche DP in Edmed accepted that s 322(3) of the 1998 Act provided that impairments from the same injury could be assessed together regardless of whether they arose from the same incident, in order for them to be assessed together they must result from the same pathology.
The Arbitrator further considered that the reasons given by the AMS for the apportionment were without explanation, but he was bound by s 326(1) of the 1998 Act to apply the assessment certified.
The Arbitrator was of the view that the following matters were conclusively presumed to be correct:
“(a) For the injury of 14 November 2011 Ms Ozcan has suffered a 3% WPI in relation to the right shoulder, and 4% in relation to the thoracic and lumbar areas of the spine. These pathologies arose out of the same incident and can be assessed together pursuant to s 322(3), giving an entitlement of 7% WPI.
(b) For the injury of 3 May 2012 Ms Ozcan has suffered a 4% WPI in relation to the thoracic and lumbar areas of the spine.
(c) For the injury of 26 September 2012 Ms Ozcan has also suffered a 4% WPI in relation to the thoracic and lumbar areas of the spine.”
The Arbitrator observed that he was not able to determine the nature of the injury to the thoracic spine on 14 November 2011, so that he could not make a determination regarding the aggregation. He said that in accordance with the authorities, he was unable to find that the injuries to the thoracic spine could be aggregated with the lumbar spine injuries. He remarked that the pathologies were different and related to different levels of the spine. He accepted, however, that the three injuries to the lumbar spine could be aggregated as the pathology was in the nature of degenerative changes. The Arbitrator said that this resulted in 7% WPI in respect of the appellant’s lumbar spine. Additionally, the Arbitrator was satisfied that the injuries on 3 May 2012 and 26 September 2012 were aggravations of degenerative changes in the thoracic spine and the pathology arising in each event was therefore the same. The appellant’s impairment of the thoracic spine was therefore 5% WPI.
The Arbitrator concluded that as the assessments for the lumbar spine and the thoracic spine were unable to be aggregated, the appellant did not meet the threshold requirement in s 66(1) of the 1987 Act of having greater than 10% WPI so that there was no entitlement to lump sum compensation.
The Certificate of Determination issued on 23 September 2019 records:
“The Commission determines:
1. There will be an award in favour of the respondent regarding the claim for lump sum compensation.
2. The respondent will pay the applicant’s section 60 expenses upon production of accounts receipts and/or HIC [Medicare] documentation.”

GROUNDS OF APPEAL

The appellant brings three grounds of appeal, alleging that the Arbitrator erred as follows:
(a) Ground One: the Arbitrator erred in fact and law by failing to conclude that all of the impairments resulting from the three injuries are to be compensated as a single WPI;
(b) Ground Two: the Arbitrator erred in law by only considering s 322(2) of the 1998 Act and not s 322(3) of the 1998 Act in the context of whether the appellant’s impairment results from the injuries suffered on 14 November 2011, and
(c) Ground Three: the Arbitrator erred in fact and law when he failed to apply the terms of the MAC.

LEGISLATION

Section 4 of the 1987 Act defines injury. It relevantly provides:
“4     Definition of ‘injury’
In this Act—
injury—
(a)     means personal injury arising out of or in the course of employment,
(b)     includes a disease injury, which means—
(i) a disease that is contracted by a worker in the course of employment but only if the employment was the main contributing factor to contracting the disease, and
(ii) the aggravation, acceleration, exacerbation or deterioration in the course of employment of any disease, but only if the employment was the main contributing factor to the aggravation, acceleration, exacerbation or deterioration of the disease, and
--.”
Section 66 of the 1987 Act provides for the entitlement to compensation in respect of permanent impairment arising out of injury. It provides:
“66    Entitlement to compensation for permanent impairment
(1)     A worker who receives an injury that results in a degree of permanent impairment greater than 10% is entitled to receive from the worker's employer compensation for that permanent impairment as provided by this section. Permanent impairment compensation is in addition to any other compensation under this Act.
Note: No permanent impairment compensation is payable for a degree of permanent impairment of 10% or less.
(1A) Only one claim can be made under this Act for permanent impairment compensation in respect of the permanent impairment that results from an injury.
(2)     The amount of permanent impairment compensation is to be calculated as follows—
(a) if the degree of permanent impairment is greater than 10% but not greater than 30%, the amount of permanent impairment compensation is to be calculated as follows—
(b) if the degree of permanent impairment is greater than 30% but not greater than 50%, the amount of permanent impairment compensation is to be calculated as follows—
(c) if the degree of permanent impairment is greater than 50% but not greater than 55%, the amount of permanent impairment compensation is $242,010,
(d) if the degree of permanent impairment is greater than 55% but not greater than 60%, the amount of permanent impairment compensation is $309,020,
(e) if the degree of permanent impairment is greater than 60% but not greater than 65%, the amount of permanent impairment compensation is $376,030,
(f) if the degree of permanent impairment is greater than 65% but not greater than 70%, the amount of permanent impairment compensation is $443,030,
(g) if the degree of permanent impairment is greater than 70% but not greater than 74%, the amount of permanent impairment compensation is $510,040,
(h) if the degree of permanent impairment is greater than 74%, the amount of permanent impairment compensation is $577,050,
where D is the number derived by expressing the degree of permanent impairment as D%.
(2A) To the extent to which the injury results in permanent impairment of the back, the amount of permanent impairment compensation calculated in accordance with subsection (2) is to be increased by 5%.
Example 1: A person suffers 12% permanent impairment. Under subsection (2), the amount of permanent impairment compensation to which he or she is entitled is $25,420. If the whole of the impairment is to the back, the compensation payable in relation to the back will be the whole $25,420. Under this subsection, that $25,420 will be increased by 5%, yielding $26,691.
Example 2: A person suffers 50% permanent impairment. Under subsection (2), the amount of permanent impairment compensation to which he or she is entitled is $175,000. If two-thirds of the impairment is to the back, the compensation payable in relation to the back will be two-thirds of $175,000, or $116,666.67. Under this subsection, that $116,666.67 will be increased by 5%, yielding $122,500. The total compensation payable for the impairment will therefore be $180,833.33.
(3)     The amount of permanent impairment compensation is to be calculated under this section as it was in force at the date the injury was received.”
The assessment of the degree of impairment of an injured worker is to be assessed in accordance with s 322 of the 1998 Act as follows:
“322 Assessment of impairment
(1)     The assessment of the degree of permanent impairment of an injured worker for the purposes of the Workers Compensation Acts is to be made in accordance with Workers Compensation Guidelines (as in force at the time the assessment is made) issued for that purpose.
(2)     Impairments that result from the same injury are to be assessed together to assess the degree of permanent impairment of the injured worker.
(3)     Impairments that result from more than one injury arising out of the same incident are to be assessed together to assess the degree of permanent impairment of the injured worker.
Note: Section 65A of the 1987 Act provides for impairment arising from psychological/psychiatric injuries to be assessed separately from impairment arising from physical injury.
(4)     An approved medical specialist may decline to make an assessment of the degree of permanent impairment of an injured worker until the approved medical specialist is satisfied that the impairment is permanent and that the degree of permanent impairment is fully ascertainable. Proceedings before a court or the Commission may be adjourned until the assessment is made.”
Section 326 of the 1998 Act provides for the status of medical assessment certificates issued by an AMS. Section 326 provides:
“326 Status of medical assessments
(1) An assessment certified in a medical assessment certificate pursuant to a medical assessment under this Part is conclusively presumed to be correct as to the following matters in any proceedings before a court or the Commission with which the certificate is concerned—
(a) the degree of permanent impairment of the worker as a result of an injury,
(b) whether any proportion of permanent impairment is due to any previous injury or pre-existing condition or abnormality,
(c) the nature and extent of loss of hearing suffered by a worker,
(d)whether impairment is permanent,
(e) whether the degree of permanent impairment is fully ascertainable.
(2) As to any other matter, the assessment certified is evidence (but not conclusive evidence) in any such proceedings.”

SUBMISSIONS

Ground One: The Arbitrator erred in fact and law by failing to conclude that all of the impairments resulting from the three injuries are to be compensated as a single WPI

The appellant’s submissions

The appellant refers to the claim pleaded in Part 5.6 of the ARD, in which the appellant claimed a single sum in respect of 24% WPI resulting from injury to the appellant’s various body parts. The appellant also refers to Part 4 of the ARD, where the appellant identified three injurious events, being:
(a)    injury to the lumbar spine, cervical spine and right shoulder on 14 November 2011;
(b)    an aggravation of her back condition on 3 May 2012, and
(c)    aggravation of all of her injuries on 26 September 2012.
The appellant says that initially the respondent disputed various injuries, but that when the matter came to arbitration on 17 April 2019, the parties agreed to orders remitting the matter to the Registrar for referral to the AMS in the terms set out in the consent orders. The appellant submits that as a consequence of the consent orders, it was no longer disputed that the appellant suffered injury to her lumbar spine, thoracic spine, cervical spine, right upper extremity (shoulder) and the upper digestive tract on 14 November 2011. The appellant says that it was also not disputed that the appellant suffered further injury to the thoracic spine and lumbar spine on 3 May 2012 and 26 September 2012.
The appellant asserts that it is important to note that the consent orders did not involve any amendment to Part 5 of the ARD, and the appellant continued to seek an order for permanent impairment compensation resulting from the injury on 14 November 2011.
The appellant refers to the MAC issued on 7 June 2019, in which the AMS accepted that the appellant suffered injury to the spine as well as the right upper extremity in the first injury. The appellant says that the AMS also accepted that the second and third injuries affected the thoracic and lumbar spine. The appellant further refers to the various assessments by the AMS of each body part and submits that it is important to note that in respect of the thoracic and lumbar spines, the AMS initially assessed a single impairment before proceeding to apportion the impairment between the three injuries in accordance with the terms of the referral. The appellant says that the consent orders used the singular and not the plural of the word “impairment” and contends that the AMS was not asked to make separate assessments of the impairments resulting from each injury but rather was asked to apportion the contribution of each injury to the overall impairment. The appellant submits that it is significant that the AMS apportioned the impairment of the thoracic and lumbar spines between the three injuries equally.
The appellant reproduced s 66 of the 1987 Act. The appellant submits that s 66 in its terms requires that compensation is to be paid in respect of the impairment that results from the injury. The appellant contends that the meaning of the term “results from” is well settled.
The appellant refers to the passage from Kooragang[19] in which Kirby P (as his Honour then was) set out the test of causation. The appellant also referred to Clarke J’s review in Sutherland Shire Council v Baltica General Insurance Company Ltd[20] in which his Honour considered Brennan J’s observations in Accident Compensation Commission v CE Heath Underwriting and Insurance (Aust) Pty Ltd,[21] which the appellant says is authority for the proposition that a loss or incapacity results from an injury whenever the injury materially contributed to the outcome. The appellant asserts that the law is that the decision maker does not look to either a sole or proximate cause of the loss or impairment.
[19] Kooragang, 461–464.
[20] (1996) 12 NSWCCR 716.
[21] [1994] HCA 68; 68 ALJR 525.
The appellant refers to Murphy and the principles discussed by Roche DP, who said (omitting citations):
“Moreover, even if the fall at Coles contributed to the need for surgery, that would not necessarily defeat Ms Murphy’s claim. That is because a condition can have multiple causes. The work injury does not have to be the only, or even a substantial, cause of the need for the relevant treatment before the cost of that treatment is recoverable under s 60 of the 1987 Act.
Ms Murphy only has to establish, applying the commonsense test of causation that the treatment is reasonably necessary ‘as a result of’ the injury. That is, she has to establish that the injury materially contributed to the need for the surgery.”[22]
[22] Murphy, [57]–[58].
The appellant submits that, applying the settled legal principles, the total impairment in both the thoracic spine and the lumbar spine results from the injury on 14 November 2011 as long as that injury materially contributes to the impairment that exists. The appellant maintains that in this case, there is one impairment in respect of each of the appellant’s body systems and that the AMS was of the view that one third of the impairment of the thoracic and lumbar spines results from the first injury. The appellant contends that a contribution of at least one third of the overall impairment more than satisfies the requirement that the injury materially contributed to the impairment. The appellant says that the entirety of the impairment is attributable to the first injury, provided that there is no break in the causal chain of connection.
The appellant also refers to the principles set out in State Government Insurance Commission v Oakley[23] discussed by Mason P, with whom Meagher JA and Barr J agreed, in Government Insurance Office of NSW v Aboushadi[24] that:
“…
(1)where the further injury results from a subsequent accident, which would not have occurred had the plaintiff not been in the physical condition caused by the defendant’s negligence, the added damage should be treated as caused by that negligence;
(2) where the further injury results from a subsequent accident, which would have occurred had the plaintiff been in normal health, but the damage sustained is greater because of aggravation of the earlier injury, the additional damage resulting from the aggravated injury should be treated as caused by the defendant’s negligence; and
(3) where the further injury results from a subsequent accident which would have occurred had the plaintiff been in normal health and the damage sustained include no element of aggravation of the earlier injury, the subsequent accident and further injury should be regarded as causally independent of the first.
…
The appellant submitted that these principles do not apply to a situation (like the present) where the second incident (here, the 1991 accident) was itself tortious. It was submitted that, in those circumstances, the second tortfeasor takes the victim as he or she is found. So be it. But the question at issue is the extent of liability of the first tortfeasor in a situation where the continuing adverse impact of the first tort is discernible. It is not the law that the commission of a second tort, affecting an already vulnerable plaintiff, by itself puts an end to the liability of the defendant responsible for the first tort.”[25]
[23] (1990) 10 MVR 570; [1990] Aust Torts Reports 81-003 (Oakley).
[24] [1999] NSWCA 396 (Aboushadi).
[25] Aboushadi, [22]–[23].
The appellant cites Faulknerv Keffalinos,[26] in which Windeyer J observed:
“There is I think a critical distinction between a supervening happening that prevents a particular damage occurring as a result of the tort and a supervening happening that causes the harm caused by the tort to have added gravity. In the first class of case the supervening event diminishes the damages which flow from the tort: in the second class it merely adds to them, so that the tortfeasor responsible for the first accident remains liable for the harm he caused, which is not merged in the combined result of his wrongdoing and the later event. The distinction is not always either easily made or preserved.”[27]
[26] (1971) 45 ALJR 80 (Faulkner).
[27] Faulkner, [85].
The appellant submits that there is no suggestion in this case that either of the later two injuries constituted a novus actus and that the respondent did not argue that there was such an intervention.
The appellant also cites Johnson No 1, in which Garling J of the Supreme Court considered that in circumstances where a worker was making a claim for WPI, the Medical Appeal Panel was in error by making a deduction from the WPI because of a subsequent injury with a different employer. The appellant explains that contrary to the Arbitrator’s understanding of that case, the conclusion in Johnson No 1 was not based on an interpretation of s 323 of the 1998 Act but was an application of the general principles of law, consistent with those identified in Aboushadi and the decision of Harrison AsJ in Nicol. The appellant reproduced the following passages from Johnson No 1:
“As set out in [25] above, the AMS concluded that the plaintiff’s chronic condition caused by her NSW Education injury was exacerbated by the later Hostel injury. Although the Panel found error in the AMS Certificate, that error arose because of the incorrect use by the AMS of the mechanism provided for in s 323 of the 1998 Act. Instead of applying s 323 according to its terms (which relate to a pre-existing condition) the AMS had applied those provisions to the subsequent Hostels injury. At no time did the Panel in its reasons depart from the diagnosis of the plaintiff’s condition, or the extent of the assessed whole person impairment.
Rather, as [110] of the Panel’s Certificate shows, the Panel considered:
‘... the question of apportionment between the subject work injury and the psychological injury sustained ... whilst in the employ of [Hostels].’
The Panel’s ultimate determination of 6% whole person impairment was the end result of the consideration and determination of this question.
It is significant that the Panel did not conclude that the later injury was of a kind or nature that severed the causal chain between the NSW Education injury and the plaintiff’s impairment. If it had come to such a conclusion, then it was obliged to find that there was no impairment as a result of the NSW Education injury. However, to the contrary, it concluded that the plaintiff’s impairment resulted from the NSW Education injury and the later Hostels injury.
The task required by ss 9 and 9A of the 1987 Act is for a determination to be made about whether the relevant employment was a substantial contributing factor to the injury. If it was, then the AMS or the Panel is to assess the permanent impairment, by a clinical assessment of the claimant, as they present on the day of the assessment having regard to the matters set out in Clause 1.6 of the Guidelines. That task does not involve any process of apportionment between injuries.
Section 323 of the 1998 Act provides an exception to that general approach, but only in the limited circumstances which that provision contemplates. Here those provisions did not apply.
For these reasons, I am satisfied that the Panel’s Certificate contained an error on the face of it, and the plaintiff is entitled to succeed on her claim.”[28]
[28] Johnson No 1, [63]–[69].

The appellant says that the issue in Johnson No 1 was whether there was a new intervening event that severed the causal connection with the original injury. It was not a question of whether it was the same pathology and no reference was made to s 322 of the 1998 Act. The appellant asserts that when Garling J’s reasons are read and understood, there is no basis for the Arbitrator to distinguish Johnson No 1 from this case.
The appellant also cites the following passages from Nicol, in which Harrison AsJ said:
“I accept that the decision on causation of MrNicol’s depression is essentially a medical opinion, but the Appeal Panel’s decision must nevertheless be made in accordance with the statutory requirements, including s 9A(1) of the Workers Compensation Act. The Appeal Panel did not specifically set out the statutory requirements of s 9A(1). The language used by the Appeal Panel also indicated that the new injury caused MrNicol’s symptoms to recur, yet made no reference to any novus actus that broke the chain of causation from MrNicol’s earlier injury sustained at Macquarie University.
The characterisation of the new injury as causing symptoms to recur suggests that the new injury and prior injury are linked. Based upon the decision of Aboushadi (which I have set out above), the present circumstances appear to fall into the second category. In other words, the further injury which resulted at Cambridge would have occurred even if MrNicol had been in normal health, but the damage sustained was greater because it was an aggravation of the earlier injury from Macquarie University. It is this additional damage resulting from the aggravated injury that remains causally linked to the first injury at Macquarie University. While Macquarie University submitted that the aggravation of an earlier injury does fall within the scope of the statutory definition of ‘injury’ under s 4 of the Workers Compensation Act, it does not follow that the aggravation alone results in a new injury unless the causal chain has been broken.
The Appeal Panel also made reference to MrNicol’s improvement in condition as constituting a remission of the first injury. The Appeal Panel did not refer to MrNicol being on any medication at that time. Putting to one side the inconsistent statements of MrNicol regarding his depression, this improvement does not constitute the required novus actus to snap the causative connection as set out in Kooragang.
In my view, the Appeal Panel’s reasoning on causation discloses that it misapplied its statutory task and thereby constructively failed to exercise its jurisdiction. The Appeal Panel’s decision is vitiated by jurisdiction[al] error.”[29]
[29] Nicol, [144]–[147].
The appellant points out that as in Johnson No 1, the conclusion in Nicol was arrived at without reference to s 322 of the 1998 Act.
The appellant refers to s 66 of the 1987 Act which, despite amendments to that section in 2000 and 2012, the appellant says, has always commenced with the words “a worker who receives an injury that results in …”. The appellant maintains that the phrase “injury that results in” has been consistently interpreted by courts in accordance with the meaning attributed to it in the above authorities. The appellant says that Parliament has accepted that interpretation by continuing to re-enact the section in the same terms. The appellant points out that s 322 was introduced into the 1998 Act in 2001, at which time the relevant term used in s 66 of the 1987 Act was not amended. It can therefore be inferred that there is nothing in the enactment of s 322 that changes the meaning of the words of s 66. The appellant relies on Public Service Association and Professional Officers Association Amalgamated Union of New South Wales v Industrial Relations Secretary on behalf of the Department of Justice[30] as authority for that proposition. The appellant contends that if the legislature had intended to change the meaning of s 66 of the 1987 Act, it would have been simple to add words to the section such as “subject to s 322 of the 1998 Act,” which it did not do.
[30] [2015] NSWCA 386, [66].
The appellant asserts that the Arbitrator misdirected himself when he considered that the decision in Edmed was definitive of the issue in this case. The appellant referred to the Arbitrator’s observation that the principle of “material contribution” is not concerned with the calculation of whole permanent impairment itself. The appellant submits that the Arbitrator provided no basis for that contention.
The appellant maintains that the basis upon which the Arbitrator distinguished Johnson No 1 and Nicol was not correct and that there was no explanation as to why the decision in Murphy could be distinguished because it concerned a claim for s 60 expenses.

The respondent’s submissions

The respondent submits that it was common ground that the right shoulder was only injured in the first incident on 14 November 2011. The respondent refers to the findings of the AMS, which included the finding that the total impairment resulting from the first injury was 7% WPI.
The respondent says that, at arbitration, it argued that:
(a)    the AMS was not asked to combine the assessments and was not asked to provide an assessment of the total WPI so that the AMS’s conclusions on those matters were not conclusively presumed to be correct;
(b) section 322(2) of the 1998 Act applied, which attracted the principles set down in Edmed. The respondent did not accept that the pathology in each body part was the same, so that the impairments could not be aggregated;
(c)    there was no injury to the thoracic spine pleaded in the ARD and the appellant gave no account of such injury occurring in the event on 14 November 2011;
(d)    because the right shoulder was only injured in the incident on 14 November 2011, there was no commonality between the incident on 14 November 2011 and the later two events in 2012. There was therefore no ability to combine the impairments attributed to the first injury with the remaining impairment, and
(e) accordingly, the appellant’s impairments did not traverse the threshold of being greater than 10% WPI required by s 66(1) of the 1987 Act.
The respondent submits that the appellant made no submissions either at the arbitration or on appeal that traversed the respondent’s argument that both subss 322(2) and 322(3) of the 1998 Act applied, as did the principles in Edmed. The respondent says that the appellant’s argument is that s 322(3) applies because of the accepted law on causation. That is, that the loss sustained by the appellant as assessed by the AMS resulted from the injuries suffered by the appellant on 14 November 2011.
The respondent submits that it did not and does not dispute that the principles of causation (which involves a question of fact) established in the various authorities referred to by the appellant are correct. The respondent advises that for that reason, it does not propose to reiterate or comment on the decisions the subject of the appellant’s submissions.
The respondent contends that in circumstances where there is more than one incident involved, the assessment of an entitlement to lump sum compensation pursuant to s 66 of the 1987 Act is a two-step process. The respondent submits that the first step is to apply the principles of causation to determine whether the evidence supports a finding that more than one injury occurred, applying s 4 (the definition of injury) and s 9A (whether employment was a substantial contributing factor) of the 1987 Act. The respondent says that the second step is to consider whether the injuries result from the same or identical pathology in order to permit the aggregation of the impairments.
The respondent asserts that the Arbitrator’s decision was correct and there was no error of fact, law or discretion.
The respondent reiterates that there was no dispute that the appellant suffered separate injuries that may or may not have resulted in an entitlement to lump sum compensation. The respondent however disputed, and maintains that dispute, that each of the injuries resulted in the same or identical pathology and that aggregation was available. The respondent also did not and does not accept that the two later incidents materially contributed to the pathology suffered in the initial incident or that the subsequent injuries were causally linked to the injury on 14 November 2011.
The respondent submits that different incidents can result in injuries to the same assessable body parts and still result from dissimilar pathologies. It says the circumstances of the injuries discussed in Edmed are a prime example of this. The respondent says that whether the injuries involve the same pathologies is a question of fact.
The respondent contends that to satisfy the first step towards establishing causation, the appellant is required to satisfy the Arbitrator that there was a causal link between the injury on 14 November 2011 and the subsequent injuries. The respondent asserts that the Arbitrator was not prepared to accept there was such a link in respect of the thoracic spine because of a lack of persuasive evidence as to the nature of the thoracic injury. The respondent says that the Arbitrator’s conclusion was not an appellable error.
The respondent submits that at the arbitration, the appellant made no submissions about the nature of the pathology arising from each injury, or about what evidence justified a causal link between each of the injuries. The respondent submits that this was probably because of the lack of any reference to the thoracic spine being injured in the first injury in the appellant’s statement and the absence of complaint of such injury in the ARD. The respondent submits further that there was a lack of contemporaneous complaints of symptoms in the thoracic spine and such symptoms were not recorded until either 2014 or 2015.
The respondent asserts that the appellant relied only upon:
(a)    the terms of the referral to the AMS;
(b)    the apportionment made by the AMS in the MAC, and
(c)    the AMS having combined the assessments to amount to 15% WPI.
The respondent submits that because the AMS was not asked to make a combined assessment, by operation of s 326 of the 1998 Act, the AMS’s opinion is not binding in that regard.
The respondent maintains that the Arbitrator did not err in his factual determination that there was no causal link between the thoracic spine and the injury on 14 November 2011. The respondent contends that before any notion of a novus actus interveniens could be considered in relation to the injury to the thoracic spine, it was necessary for the appellant to establish what the injury actually was and to provide persuasive supporting evidence that there was a connection between the first injury and the subsequent injuries. The respondent submits that the Arbitrator did not accept that there was sufficient evidence available to establish the chain of causation and accordingly, the question of whether a novus actus occurred was irrelevant. The respondent concludes that there was “ample justification for taking this approach to the evidence.”[31]

Ground Two: The Arbitrator erred in law by only considering s 322(2) of the 1998 Act and not s 322(3) of the 1998 Act in the context of whether the appellant’s impairment results from the injuries suffered on 14 November 2011

[31] Respondent’s amended submissions, [24].

The appellant’s submissions

The appellant submits that s 322(3) of the 1998 Act is relevant. The appellant maintains that by entering into the consent orders, the parties accepted that the appellant had suffered injury to the right upper extremity, thoracic spine and lumbar spine in the incident on 14 November 2011. The appellant submits that as those injuries occurred in the same event, the impairments from those injuries are to be combined in accordance with s 322(3). The appellant refers to s 65(2) of the 1987 Act, which also provides that “if a worker received more than one injury arising out of the same incident, those injuries are to be treated as one injury for the purposes of this Division.” The appellant says that applying both s 322(3) of the 1998 Act and s 65(2) of the 1987 Act, it is clear that the impairments can be assessed together.
The appellant contends that Edmed was concerned with a different matter. The appellant says that in Edmed, it was not at any stage argued that the entire percentage of WPI resulted from the first injury. The appellant says that this was probably so because in Edmed, the worker had to the relevant extent fully recovered from the first injury and the second injury would have amounted to a novus actus interviens which broke the chain of causation. The appellant maintains that Edmed cannot be taken as authority for the proposition that s 322 of the 1998 Act displaces the established law of causation. The appellant asserts that to the extent that it may be considered that the decision in Edmed has that effect, the decision is wrong and contrary to a long line of authority from superior courts both before and after the enactment of s 322 of the 1998 Act.

The respondent’s submissions

The respondent contends that the decision in Johnson No 1 is irrelevant because it did not involve more than one compensable injury. The respondent submits that the issue in Johnson No 1 was about the incorrect application of s 323 of the 1987 Act and there was no dispute about whether the pathology was different between the compensable injury and the non-compensable injury. The respondent says that in the present case, there was such a dispute.
The respondent submits that where a worker suffers injury from more than one event, s 322(2) applies, which is the case in the present matter. The respondent describes s 322(2) as providing a formula for assessing how the quantification of compensation is to be arrived at. The respondent says that Edmed requires that the injury, meaning the pathology arising in each event, must be the same before aggregation can take place. The respondent maintains that the Arbitrator’s conclusion was correct.
The respondent contends that in cases where the pathology arising from each event is the same, it probably establishes a causal link between each injury. The respondent says that it is therefore unlikely that Edmed and the application of s 322(2) would ever conflict with the principles of causation. The respondent submits that s 322(2) is intended to provide a method of assessment of injury or injuries once the injuries have been established by applying the principles of causation. The respondent describes the appellant’s argument as an attempt to “circumvent the general operation of the legislation”[32] and that if the appellant’s submission is correct, s 322(2) of the 1998 Act would have little or no work to do.

Ground Three: The Arbitrator erred in fact and law when he failed to apply the terms of the MAC

[32] Respondent’s amended submissions, [27].

The appellant’s submissions

The appellant submits that ultimately, the Arbitrator did not consider the question he was required to decide, that is, whether the injury to the thoracic and lumbar spine on 14 November 2011 materially contributed to the impairment assessed by the AMS. The appellant says that the Arbitrator did accept that the MAC conclusively proved that the appellant suffered from the following impairments:
(a)    3% WPI in respect of the right upper extremity:
(b)    5% WPI of the thoracic spine, and
(c)    7% WPI in respect of the lumbar spine.
The appellant confirms that the Arbitrator was satisfied that the AMS’s finding that each of the first, second and third injuries contributed 4% (or one third) of the overall spinal impairments was conclusively presumed to be correct.
The appellant contends that once those matters are accepted, the only conclusion that is properly available is that the entirety of the impairments to the thoracic and lumbar spines results from the injury on 14 November 2011. The appellant points out that the injury on 14 November 2011 also involved the right shoulder, so that the WPI assessment for the right upper extremity can be included in the total assessment, producing an overall impairment of 15% WPI.

The respondent’s submissions

The respondent submits that even if the Arbitrator determined that the incident on 14 November 2011 resulted in injuries to the lumbar and thoracic spine, which were the same injuries suffered in the two later events, aggregation of all the impairments would still not be available because the injury on 14 November 2011 included a shoulder injury which was not common to the later two events. The respondent relies on a number of decisions supporting that proposition.[33] The respondent maintains that where aggregation is available in respect of some of the injuries, it is not permissible to combine an assessment which arose from a separate injury that did not result in the same pathology.
[33] Warwar; Mordaunt; Stagg; Hafizi.
The respondent concludes that the approach taken by the Arbitrator was correct and does not give rise to an error of fact or law.

Further Submissions

Both parties’ submissions in respect of Johnson No 1 were made before the appeal from that decision was determined by the Court of Appeal. On 20 December 2019, the Court of Appeal handed down its decision, Secretary, New South Wales Department of Education v Johnson.[34] In order to afford procedural fairness to both parties, the parties were invited to make further submissions relevant to that decision.
[34] [2019] NSWCA 321 (Johnson No 2).
The appellant referred to the Court of Appeal’s observations that:
(a) there is no difference between the legal view of causation in tort and causation in the field of workers compensation, except that in workers compensation, it is unnecessary to establish that the incapacity was the probable and natural consequence of the injury. That is, there is no question of foreseeability, and
(b) it is sufficient to say incapacity results from the injury by chain of legal causation unbroken by a novus actus interveniens.[35]
[35] Johnson No 2, per Emmett AJA (with Macfarlan JA agreeing), [53].
The appellant submits that the decision in Johnson No 2 confirms the test of causation is that which is set out in the cases relied on in his primary submissions. The appellant says that their Honours also held that the phrase “the degree of permanent impairment … as a result of an injury” calls for an enquiry as to the causal connection between the degree of assessed permanent impairment on the one hand, and the compensable injury on the other. The appellant says that it was necessary for the AMS and the MAP to assess the degree of WPI of the worker that was caused by or attributable to the first injury and in doing so, the common law principles of causation applied.[36]
[36] Johnson No 2, per Emmett AJA (with Macfarlan JA agreeing), [55].
The appellant observes that Emmett AJA considered the principles identified in both Aboushadi and Oakley. The appellant says that the categories in Oakley should be seen as merely the application of the more general principles of causation. The appellant contends that alternatively, if the Oakley categories are accepted as covering the field, it then follows that in all cases where there is no novus actus and the initial injury contributes to the final impairment, the effect of the subsequent injury must fall within one of the first two categories.
The appellant refers to the approach taken by Simpson JA, in which she considered that the three categories in Oakley applied and held that the MAP had not considered those categories.
The appellant contends that in this case, the thoracic spine and lumbar spine have each been the subject of repeated insults. The appellant says the injuries resulted in soft tissue injuries which, for the purpose of the assessment of impairment, were classed as DRE category 2 and so fell within the second category referred to in Oakley. The appellant submits that, in those circumstances, the entirety of the WPI results from the injury on 14 November 2011.

The respondent submits that Johnson No 2 was fundamentally about errors by the MAP in assessing the WPI of a worker who had a subsequent injury in the employ of another entity covered by a different compensation scheme. The respondent contends that the application of the common law principles of causation discussed in Johnson No 2 were not in issue in this matter. The respondent says that Johnson No 2 did not concern a claim pursuant to s 322(2) of the 1998 Act and so the requirements in relation to aggregation were not considered.
The appellant asserts that this case is about three different injuries in which the pathologies were not identical. Further, the respondent says that the Arbitrator made a finding on the available evidence that he was unable to determine the nature of the thoracic injury said to have occurred on 14 November 2011.
The respondent submits that theoretically, had the present case involved further injury which was not compensable but could be causally related to one or all of the injuries, such as in Johnson No 2, and were identical pathologies, then s 322(2) of the 1998 Act would apply so that the subsequent injury could be aggregated. The respondent submits that Johnson No 2 involved only one compensable injury with identical pathology so that Johnson No 2 has no application in this matter.

RELIEF SOUGHT

The appellant submits that the appeal should be upheld and an award should be entered in favour of the appellant for payment of $22,000 in respect of 15% WPI resulting from injuries on 14 November 2011.
The respondent seeks for the appeal to be dismissed and the Certificate of Determination dated 23 September 2019 confirmed.

DISCUSSION

Applying s 326 of the 1998 Act, the opinion of the AMS that the appellant suffered both 5% WPI of the thoracic spine and 7% of the lumbar spine as a result of the three injuries is conclusively presumed to be correct. In the referral, the AMS was clearly directed to provide an opinion in respect of apportionment between the three injuries of the total impairment of the lumbar spine, thoracic spine and upper digestive tract. The AMS found no impairment of the upper digestive tract and apportioned the total impairment of the lumbar spine and thoracic spine, which was 12% WPI, in equal proportions of one third for each injury. The assessments of a combined 4% whole person impairment of the lumbar spine and thoracic spine together in respect of each injury is therefore also conclusively presumed to be correct. These observations accord with the Arbitrator’s conclusions, and no challenge to those conclusions is made in this appeal.

Ground One

The appellant’s first ground of appeal is that the Arbitrator erred in failing to conclude that all of the appellant’s impairments should be combined and assessed as a single WPI because of the application of the common law principles relating to the phrases ‘results from’ and the ‘material contribution’ from the first injury to the subsequent impairments.
The Arbitrator observed that, while the principle applied to establish a causal connection between two injuries, it did not involve the calculation of the whole person impairment. The Arbitrator did not accept the appellant’s argument that Edmed could be distinguished. He distinguished Nicol and Johnson No 1 because in his view, neither of those cases involved a consideration of s 322 of the 1998 Act. The Arbitrator disagreed with the appellant’s submission that the circumstances of this case did not conflict with the principles enunciated in Edmed. The Arbitrator considered that the ratio in Edmed dealt with both subss 322(2) and 322(3) of the 1998 Act. The Arbitrator further considered that he was bound by the apportioned losses as assessed by the AMS and could not award a total impairment because the AMS had not been asked to make that assessment.
The appellant submits that because of the terms of the referral, there was no longer a dispute that the appellant had injured her right shoulder, thoracic spine and lumbar spine in the incident on 14 November 2011 and that it was not disputed that the appellant suffered further injuries to her thoracic and lumbar spines in the two later injuries. This is undoubtedly correct.
Section 66(1) of the 1987 Act provides that a worker who receives “an injury that results in” an impairment is, if the permanent impairment exceeds 10%, entitled to compensation. Part 7 of Ch 7 of the 1998 Act, which includes ss 319, 322, 323 and 326, deals with medical assessments in relation to medical disputes concerning entitlement to compensation. Section 319 of the 1998 Act defines a medical dispute to include a dispute about the degree of permanent impairment “as a result of an injury.” Section 322 of the 1998 Act speaks about impairments that “result from” the same injury (subs (2)) or more than one injury (subs (3)). Section 323 of the 1998 Act requires a deduction for any pre-existing impairment to be made in an assessment of the degree of impairment “resulting from an injury”. Section 326 of the 1998 Act provides an assessment certified in a MAC is conclusively presumed to be correct in respect of the degree of impairment “as a result of an injury”.
All of these sections refer to the impairment as one which results from an injury. This necessarily raises the question of causation between the injury and the resulting impairment (in this case, the second question of causation identified by Emmett AJA in Johnson No 2). In the circumstances of this case, by the time the matter was referred to the AMS, there was no issue that the appellant had suffered the injuries referred to in the consent orders. The issue was the degree of impairment attributable to any of the three injuries.
A consideration of the relevant caselaw begins with a reference to Kooragang and the passage often cited from the judgment of Kirby P (as his Honour then was), as follows:
“The result of the cases is that each case where causation is in issue in a workers' compensation claim, must be determined on its own facts. Whether death or incapacity results from a relevant work injury is a question of fact. The importation of notions of proximate cause by the use the phrase ‘results from’ is not now accepted. By the same token, the mere proof that certain events occurred which predisposed a worker to subsequent injury or death, will not, of itself, be sufficient to establish that such incapacity or death ‘results from’ a work injury. What is required is a common sense evaluation of the causal chain. As the early cases demonstrate, the mere passage of time between a work incident and subsequent incapacity or death, is not determinative of the entitlement to compensation. In each case, the question whether the incapacity or death ‘results from’ the impugned work injury (or in the event of a disease, the relevant aggravation of a disease), is a question of fact to be determined on the basis of evidence, including where applicable expert opinions. Applying the second principle which Hart and Honore identify, a point will sometimes be reached where the link in the chain of causation becomes so attenuated that, for legal purposes, it will be held that the causative connection has been snapped. This may be explained in terms of the happening of a novus actus. Or it may be explained in terms of want of sufficient connection. But in each case, the judge deciding the matter, will do well to return, as McHugh JA advised, to the statutory formula and to ask the question whether the disputed incapacity or death ‘resulted from’ the work injury which is impugned.”[37]
[37] Kooragang, 463–464.
More recently, the High Court reviewed the phrase “as a result of” in Comcare v Martin[38] and observed that:
“Causation in a legal context is always purposive. The application of a causal term in a statutory provision is always to be determined by reference to the statutory text construed and applied in its statutory context in a manner which best effects its statutory purpose. It has been said more than once in this Court that it is doubtful whether there is any ‘common sense’ approach to causation which can provide a useful, still less universal, legal norm. Nevertheless, the majority in the Full Court construed the phrase ‘as a result of’ in s 5A(1) as importing a ‘common sense’ notion of causation. That construction, with respect, did not adequately interrogate the statutory text, context and purpose.”[39]
[38] [2016] HCA 43; 258 CLR 567 (Comcare v Martin).
[39] Comcare v Martin, [42].
Acting Deputy President Parker in Le Twins Pty Ltd v Luo[40] considered the application of Murphy in the context of a claim for whole person impairment. He observed:
“In my view, Murphy is an example of the requirement to consider the purpose for which causation is being determined (Comcare v Martin above).
The determination in Murphy was for the purpose of an award under s 60 in respect of surgery that had been performed. The test in Murphy was whether or not the surgery was ‘reasonably necessary’ in the circumstances. The statutory question in the present case is whether the impairment suffered by the worker in respect of the two injuries to his shoulders could be accommodated within sub-sections 322(2) or (3).
I do not regard the Arbitrator’s conclusion at [81] of her reasons that a condition may have more than one cause as incorrect. Most conditions are the result of multiple factors. The question is always whether the facts as found satisfy the statutory criterion for causation.
In my view, the Arbitrator was in error in her conclusion that Mr Luo’s impairment was caused by the injury to the right arm. That was because the injury to the right arm did not materially contribute to the injury to the left arm. That is because ‘[t]he law does not accept John Stuart Mill’s definition of cause as the sum of the conditions which are jointly sufficient to produce it. ... at law, a person may be responsible for damage when his or her wrongful conduct is one of a number of conditions sufficient to produce that damage’: March v E & M.H Stramare.”[41]
[40] [2019] NSWWCCPD 52 (Luo).
[41] Luo, [69]–[73].
In Johnson No 2, the worker suffered two psychological injuries, the first injury occurring in the course of her employment with the Secretary, NSW Department of Education (the appellant in the appeal) and the second with a different (Commonwealth) employer. There were two questions posed by the appellant in Johnson No 2 in the appeal, namely:
“(1) Whether, in the case of a subsequent injury, common law principles relating to causation apply to an assessment made under Pt 7 of Ch 7 of the [1998] Act in relation to the earlier injury.
(2) Whether in the circumstances of this case, the common law principles required the Appeal Panel to determine that the entirety of the whole person impairment assessed by it, in reliance on the assessment by the AMS, was the result of the First Injury, without allowing for apportionment on account of impairment resulting from the Second Injury.”[42]
[42] Johnson No 2, [47].
Those issues are relevant to the issues raised in this appeal.
The Court of Appeal made the following observations:
(a)    the 1987 Act, the 1998 Act and the guidelines for assessment of permanent impairment do not expressly provide for, or exclude, apportionment where there is an injury subsequent to the injury that is the subject of a claim;[43]
(b)    the AMS (or the Medical Appeal Panel) must assess the degree of permanent impairment of the person as a result of an injury. That is, it must be possible to demonstrate that there is a causal connection between the compensable injury and the impairment,[44] and
(c)    the primary judge considered that:
(i)section 323 of the 1998 Act did not apply,[45] and
(ii)it was significant that the Appeal Panel did not conclude that the second injury was of a kind or nature that severed the causal chain between the first Injury and the worker’s permanent impairment.[46]
[43] Johnson No 2, per Emmett AJA (Macfarlan JA agreeing), [12].
[44] Johnson No 2, per Emmett AJA (Macfarlan JA agreeing), [14].
[45] Johnson No 2, per Emmett AJA (Macfarlan JA agreeing), [44].
[46] Johnson No 2, per Emmett AJA (Macfarlan JA agreeing), [43]
Emmett AJA (with Macfarlan JA agreeing) concluded that there is no difference between the legal view of causation in tort and causation in the field of workers compensation, except that, in a claim for workers compensation, it is unnecessary to prove that the incapacity was the natural and probable consequence of the injury. It is sufficient that the incapacity results from the injury by a chain of legal causation unbroken by a novus actus interveniens.[47] He further concluded:
“Two causation tests are involved in a medical assessment of permanent impairment under Pt 7 of Ch 7 of the [1998] Act. The first test arises from the provisions of ss 9 and 9A of [the 1987] Act. That is to say, it must be shown that the injury that gave rise to the impairment in question arose out of or in the course of employment and that the employment was a substantial contributing factor to the injury. The second test arises from the provisions of ss 319(c) and 326(1)(a) of the [1998] Act. That is to say, it must be shown that the permanent impairment is as a result of the injury.
The phrase ‘the degree of permanent impairment of the person as a result of an injury’ appears in both ss 319(c) and s 326(1)(a) of the [1998] Act. That composite phrase requires an enquiry as to the causal connection between the degree, or percentage, of assessed permanent impairment of a worker, on the one hand, and the compensable injury, on the other. That is to say, it was necessary for the AMS and the Appeal Panel to assess the degree, or percentage, of whole person impairment of the Worker that was caused by or is attributable to the First Injury. In doing so, common law principles of causation in tort are to be applied.”[48]
[47] Johnson No 2, per Emmett AJA (Macfarlan JA agreeing), [53].
[48] Johnson No 2, per Emmett AJA (Macfarlan JA agreeing), [54]–[55].
As in Luo, the appellant in this case seeks to have her impairments aggregated. Applying the above authorities, consideration must be given to the common law principles in respect of causation, but such consideration cannot be given without regard to the statutory context. In this case, the statutory context is s 322 of the 1998 Act.
I see no reasons why s 322 of the 1998 Act, which by the text itself invites a consideration of causation of the permanent impairment, should operate without a consideration of that necessary element. That is, if the appellant can establish the fact that the first injury materially contributed to the total impairment, then the total impairment is attributable to the injury on 14 November 2011.
The appellant contends that the Arbitrator erred by failing to conclude that all of the appellant’s impairments should be combined and assessed as a single WPI. The Arbitrator declined to come to that conclusion because, in his words, “whilst the principle of material contribution will establish a causal connection between two injurious events, it is not concerned with the calculation of whole person impairment itself.”[49] The Arbitrator distinguished Nicol and Johnson No 1 on the basis that in those cases, there was no dispute about the pathology of the injuries so that s 322 of the 1998 Act did not need to be considered.
[49] Ozcan v Macarthur Disability Services Limited [2019] NSWWCC 310 (reasons), [69].
The question of whether the common law principles of causation in tort are to be applied in determining the impairment that “results from” the injury was expressly considered by the Court of Appeal in Johnson No 2. The conclusion was that they did.
The Arbitrator formed the view that the application of those principles would conflict with the decision in Edmed. Edmed involved an analysis of the meaning of subss 322 (2) and (3) of the 1998 Act. Deputy President Roche considered the definition of “injury’ in s 4 of the 1987 Act and said:
“This definition is unhelpful in determining the issue before me. In Lyons, Judge Neilson held that ‘injury’ refers to ‘both the [injurious] event and the pathology arising from it’. I accept that definition as being appropriate for many purposes under the 1987 Act and the 1998 Act. That the term ‘injury’ can have two different meanings is acknowledged in section 322(3) of the 1998 Act where reference is made to ‘Impairments that result from more than one injury arising out of the same incident...’ (emphasis added). This reference to ‘injury’ can only mean the ‘pathology’ that has resulted from the relevant work ‘incident’ or injurious event. For example, if a worker falls and suffers a broken leg and separate and distinct nerve damage in the arm, he or she has suffered more than one ‘injury’ (an injured leg and an injured arm) within the terms of section 322(3) resulting from the one ‘incident’. In other words, he or she has suffered more than one pathology (‘injury’) as a result of the one incident or injurious event. Those ‘injuries’ are to be assessed together. This interpretation is consistent with section 65(2) of the 1987 Act and is uncontroversial.
The difficulty arises when a worker suffers one pathology (‘injury’) as a result of several independent ‘incidents’ or injurious events. This situation is partly addressed in section 322(2), which provides that ‘Impairments that result from the same injury are to be assessed together to assess the degree of permanent impairment of the injured worker’ (emphasis added). The reference to ‘the same injury’ in section 322(2) cannot be a reference to ‘the same incident’ because that situation is dealt with in section 322(3). The expression ‘the same injury’ is not defined but it follows that if ‘injury’ in section 322(3) means ‘pathology’ (as it must), then, for the section to be logically consistent, it must mean the same in section 322(2). If ‘injury’ in section 322(2) means ‘pathology’ then, for section 322(2) to be consistent with section 322(3), impairments resulting from the ‘same injury’ (the same pathology) are to be ‘assessed together’ regardless of whether they arise from the same ‘incident’ or separate incidents.”[50] (emphasis in original)
[50] Edmed, [26]–[27].
Following Edmed, the result is that s 322(2) allowed aggregation of impairments from different injurious events where they involved the same pathology and s 322(3) allowed aggregation where there were injuries to different body parts in the same event. I do not see any conflict between the generally expressed common law principles discussed above and the application of s 322(2) of the 1998 Act in the manner expressed by Roche DP in Edmed. In fact, an application of the common law principles to Edmed would arrive at the same result as that determined by Roche DP.
The Arbitrator’s reasons for determination preceded both the decision in Luo and in Johnson No 2. Nonetheless, for the reasons given in both those authorities, it follows that the Arbitrator erred by considering that the principles were not relevant to an assessment of permanent impairment. The Arbitrator erred by failing to apply the common law principles in the context of s 322 of the 1998 Act, as set out in Oakley in determining whether the appellant’s impairments could be aggregated.
It follows that Ground One of the appeal succeeds. As the appellant has established error on the part of the Arbitrator. It is open for me to re-determine the issues in dispute in the appeal.[51] It is convenient to re-determine the issue raised by this ground (Issue no 1) before proceeding with the subsequent grounds of appeal as those subsequent grounds of appeal are to an extent dependent upon a resolution of this issue.
[51] Section 352(7) of the 1998 Act.

Re-determination – Issue No 1

The appellant’s argument before the Arbitrator and on appeal is that the assessments of the lumbar and thoracic spines should be combined because the injury to those body parts sustained in the first injury on 14 November 2011 materially contributed to the overall impairment in those body parts. That is, following the Oakley principles set out at [55] above, all of the assessments for the lumbar spine and thoracic spine (totalling 12% WPI) should be attributed to the injury on 14 November 2011.

The respondent maintains that there is no evidence to establish what the pathology was in the thoracic spine that resulted from the first injury and so the impairment flowing from that injury could not be the same pathology as the subsequent two impairments.
The evidence relied upon by the appellant was the opinion of the AMS that:
(a) the appellant suffered 7% WPI in respect of the lumbar spine and 5% WPI in respect of the thoracic spine, and
(b) the combined impairment flowing from the three injuries was 12% impairment, of which 4% was attributable to the first injurious event.
The appellant submits that 4% (or one third) is evidence of a material contribution.
There was other evidence that supported the causal connection between the first injury and the subsequent events.
Dr Darwish commented that the radiological investigations demonstrated changes in the cervical, thoracic and lumbosacral spine which were, in his view, most likely degenerative in nature but aggravated by the injuries on 14 November 2011 and September 2012.
Dr Khan concluded that the appellant suffered further aggravations of the initial injury on 3 May 2012 and 26 September 2012 and that those later injuries “contributed further to her initial injury of November 2011.”[52] Dr Khan was of the opinion that the appellant’s condition was caused by the frank injury on 14 November 2011, which was subsequently aggravated by the various later injuries and the nature of the work of the appellant. Dr Khan assessed the WPI of the thoracic spine as a result of injury to be 5% and assessed the appellant’s total impairment as 24%WPI. In respect of the thoracic spine, Dr Khan diagnosed a musculoligamentous injury resulting from the injury on 14 November 2011.
[52] ARD, p 96.
The evidence of the causal connection was not limited to the appellant’s evidentiary camp. Although Dr Powell concluded that he could find no evidence for assessable impairment of the thoracic spine, he diagnosed musculoligamentous injury in the thoracolumbar spine in association with degenerative disc pathology at the T7/8 level. He believed that it was reasonable to conclude that, given the mechanism of injury, the appellant suffered injuries (including to the thoracic spine), as a result of the series of frank injuries in the course of her employment.
The Arbitrator reasoned that because of the absence of evidence about the thoracic pathology arising in the first injury, he was unable to determine the nature of that injury to the thoracic spine. He was therefore unable to make any determination as to whether the thoracic spine injury occurring on 14 November 2011 could be aggregated with the later injuries.
Those reasons ignore the medical evidence that supported a causal connection between the accepted first injury to the thoracic and lumbar spine and the subsequent aggravations. The reasoning also ignores the binding assessment by the AMS that the appellant suffers from 4% WPI resulting from the first injury (which included the thoracic spine). Both Dr Khan and Dr Powell diagnosed musculoligamentous injury to the thoracic spine as a result of all three injuries. Given that there was no issue that the thoracic spine was injured, which injury resulted in an impairment and that the subsequent injuries caused further impairment I see no reason why the second category described in Oakley (as set out at [55] above) is not satisfied in respect of the thoracic spine. The damage sustained was greater because of aggravations of the earlier injury and the additional damage resulting from the aggravated injury should be causally connected to the original injury.
It must be noted that the Arbitrator accepted that the pathology in the lumbar spine was the same in respect of all three injuries resulting in 7% WPI and that finding has not been challenged on appeal. The second category described in Oakley is also satisfied in respect of the lumbar spine. That is, the material damage sustained in the first injury was aggravated by the subsequent two incidents.
Such a conclusion is not inconsistent with s 322(2) of the 1998 Act and is not inconsistent with Edmed, in which Roche DP determined that different injurious events causing the same pathology are to be assessed together.
All three injuries involved injury to the thoracic spine and lumbar spine so that the impairments attributed to each of the thoracic spine and the lumbar spine, while different pathologies, can be aggregated by operation of s 322(3) of the 1987 Act.
It follows that the impairments flowing from the thoracic spine (5%) and lumbar spine (7%) “result from” (in the common law sense) the injury on 14 November 2011 and are to be assessed together, which in the statutory context is in accordance with s 322(2) of the 1998 Act. Applying the Combined Values Chart contained in the AMA Guides for Evaluation of Permanent Impairment, Fifth Edition, the total combined impairment of the lumbar and thoracic spines is 12% WPI.
The compensation entitlement pursuant to s 66 of the 1987 Act in respect of 12% WPI is $17,050.00 plus any additional amount to be applied pursuant to s 66(2A) of the 1987 Act in respect of an injury to the back.

Ground Two

The second ground of appeal complains that the Arbitrator erred by only considering s 322(2) of the 1998 Act and not s 322(3) of the 1998 Act.
Contrary to the respondent’s submissions, the Arbitrator clearly accepted that there was an injury to the thoracic spine on 14 November 2011 (which he was bound to do). He proceeded to aggregate the impairment of the right upper extremity (3%) with the combined 4% impairment arising out of the injury on 14 November 2011 for the lumbar and thoracic spines.[53]
[53] Reasons, [89].
The Arbitrator expressly applied s 322(3) of the 1998 Act when he arrived at the following conclusion:
“It follows that the assessment certified in the MAC conclusively proves to be correct the following:
(a) For the injury of 14 November 2011 Ms Ozcan has suffered a 3% WPI in relation to the right shoulder, and 4% in relation to the thoracic and lumbar areas of the spine. These pathologies arose out of the same incident and can be assessed together pursuant to s 322(3), giving an entitlement of 7% WPI.
(b) For the injury of 3 May 2012 Ms Ozcan has suffered a 4% WPI in relation to the thoracic and lumbar areas of the spine.
(c) For the injury of 26 September 2012 Ms Ozcan has also suffered a 4% WPI in relation to the thoracic and lumbar areas of the spine.”[54]
[54] Reasons, [89].
The Arbitrator did not expressly consider the application of s 322(2), partly because he was of the view that the determination by the AMS of the total WPI was not binding because the AMS was not asked to make that assessment. In addition, the appellant had expressly advocated that he was not relying on s 322(2) of the 1998 Act.
The appellant’s argument was that s 322(3) of the 1998 Act applied, so that the 12% WPI in respect of the thoracic and lumbar spines, which “resulted from” the injury on 14 November 2011 could be aggregated with the WPI for the right upper extremity because, although they were different pathologies, they arose out of the same incident.
The Arbitrator considered that he could not aggregate the impairments of the thoracic and lumbar spines, despite noting the finding by the AMS that each date of injury contributed to the WPI regarding the thoracic and lumbar spine.[55]
[55] Reasons, [79].
The Arbitrator did not go so far as to address the application of s 322(3) in this context because he did not accept that the common law principles of causation applied. The Arbitrator’s failure to apply those principles was an error.
As McCallum JA (with Macfarlan and Meagher JJA agreeing) observed in Wang v State of New South Wales[56] (citations omitted):
“The submission invoked the decision of the High Court in Dranichnikov v Minister for Immigration & Multicultural Affairs in which it was stated that a failure to respond to a substantial, clearly articulated argument relying on established facts was a constructive failure to exercise jurisdiction. The decision is not authority for the proposition that any failure to refer to any argument put to a trial judge amounts to error. It is necessary to engage with the nature and materiality of the argument in the context of the issues in the proceedings.”
[56] [2019] NSWCA 263, [63],
In the context of the issues in these proceedings, the submission made by the appellant at arbitration was material to the matters requiring determination. It follows therefore that the Arbitrator was in error by not addressing the submissions made by the appellant that s 322(3) of the 1998 Act applied in the manner submitted.
Ground Two of the appeal however raises a further issue (Issue No 2) that requires re-determination in accordance with s 352(7) of the 1998 Act.

Re-determination – Issue No 2

The impairment to the right upper extremity cannot be aggregated with the losses arising as a result of the second and third injuries on the basis of the common law principles discussed above. The right shoulder injury did not materially contribute to the impairments of the lumbar or thoracic spine and was not the same injury (pathology). The only basis upon which the assessment of the right upper extremity could be aggregated with the other assessments is in accordance with s 322(3) of the 1998 Act.
The appellant says the impairment of the right upper extremity should be included in the assessment of the entire loss attributable to the thoracic and lumbar spines because the injury to the right shoulder occurred in the same incident on 14 November 2011, by operation of s 322(3).
The respondent’s submission in respect of the claim for the right upper extremity is simply that it cannot be aggregated with the impairments resulting from the two later injuries. This is said to be because the right shoulder was not injured in those incidents and because it is not the same pathology as the thoracic and lumbar spines.
It is well settled that s 322(3) requires that, for the impairments arising from different pathologies to be aggregated, they must have been sustained in the same injurious event. As Roche DP explained in Edmed:
“For example, if a worker falls and suffers a broken leg and separate and distinct nerve damage in the arm, he or she has suffered more than one ‘injury’ (an injured leg and an injured arm) within the terms of section 322(3) resulting from the one ‘incident’. In other words, he or she has suffered more than one pathology (‘injury’) as a result of the one incident or injurious event. Those ‘injuries’ are to be assessed together. This interpretation is consistent with section 65(2) of the 1987 Act and is uncontroversial.”[57]
[57] Edmed, [26].
This approach was also taken by Snell ADP (as he then was) in New South Wales Fire Brigades v Turton[58] as follows:
“I have already found that section 322(2) does not assist the Respondent Worker in combining the assessments, as the impairments do not result from the same injury, in the relevant sense. The other potential basis on which the assessments could be combined, for the Respondent Worker to cross the threshold in section 67(1), is if section 322(3) had application. Application of that sub-section would require more than one injury (as exists here) arising out of the same incident.”
[58] [2008] NSWWCCPD 66, [79].
The impairments of the lumbar spine and thoracic spine assessed by the AMS can be aggregated by application of both the common law principles and s 322(2) and liability rests with the respondent for a total 12% WPI. However, that does not extend to a permission to aggregate the right upper extremity impairment with the impairments attributable to the injuries on 3 May 2012 and 26 September 2012. This is because the injurious event involving the right shoulder was a different injurious event to those events occurring on 3 May 2012 and 26 September 2012 and the right shoulder injury did not materially contribute to those subsequent thoracic and lumbar spine injuries.
In such circumstances, neither subss 322(2) or 322(3) of the 1998 Act apply to allow the right upper extremity impairment to be aggregated with the impairments that result from the two later injuries. However, s 322(3) permits the 3% WPI of the right upper extremity to be aggregated with the 4% WPI of the spinal injuries assessed by the AMS as resulting from the first injury, as the Arbitrator determined. The impairment arising out of the first injurious event, that is the injury on 14 November 2011, does not reach the necessary threshold pursuant to s 66(1) of the 1987 Act so that no compensation is payable in respect of the right upper extremity.

Ground Three

The appellant asserts that the Arbitrator erred in fact and law when he “failed to apply the terms of the MAC.” Given the outcome of Ground One and Two, it is not necessary for me to address this ground of appeal, which substantially mirrors the appellant’s complaints made under the previous two grounds of appeal.

CONCLUSION

The appellant is not entitled to aggregate the whole person impairment of the right upper extremity with the losses of the thoracic spine and lumbar spine attributable to the injurious events on 3 May 2012 and 26 September 2012.
The appellant is entitled to compensation pursuant to s 66 of the 1987 Act in respect of 12% WPI of the thoracic and lumbar spines.

DECISION

Paragraph one of the Certificate of Determination dated 23 September 2019 is revoked and the following order is made in its place:
(a) The respondent is to pay the applicant $17,902.50 in respect of 12% whole person impairment of the lumbar spine and the thoracic spine (including a 5% uplift) pursuant to s 66 of the Workers Compensation Act 1987.
The Certificate of Determination is otherwise confirmed.

Elizabeth Wood

Deputy President

21 April 2020