Field and Australian Postal Corporation - [2001] AATA 1036

DECISION AND REASONS FOR DECISION [2001] AATA 1036

ADMINISTRATIVE APPEALS TRIBUNAL )

)No N2000/739 N2000/1521

GENERAL ADMINISTRATIVE DIVISION          )
           Re      Lorraine Wendy Field
  Applicant
           And    Australian Postal Corporation
  Respondent

DECISION

Tribunal Ms S M Bullock, Senior Member Dr P D Lynch, Member

Date21 December 2001
PlaceSydney

Decision The decisions under review are affirmed.

..............................................
Ms SM Bullock
Presiding MemberCatchwords
COMPENSATION - Lumbar Disc Prolapse - Permanent Impairment - Medical Expenses

Legislation
Safety, Rehabilitation and Compensation Act 1988 ss 4, 14, 16, 19, 22, 24, 27, 28

Authorities
Health Insurance Commission v Van Reesch and Anor (1996) 45 ALD 302
Zickar v MGH Plastic Industries Pty Limited (1996) 187 CLR 310
Re Welsford and Commonwealth Banking Corporation (1984) 1 AAR 42
Treloar v Australian Telecommunications Commission (1990) 26 FCR 316

REASONS FOR DECISION

21 December 2001 Ms S M Bullock, Senior Member Dr P D Lynch, Member

This is an application for review to the Administrative Appeals Tribunal ("the Tribunal") by Mrs Lorraine Wendy Field, the Applicant. Mrs Field seeks review of reviewable decisions made by the Respondent, the Australian Postal Corporation on:
(i)8 March 2000 (T18, N2000/739), which affirmed a decision of 12 January 2000, that Mrs Field's employment did not materially contribute to her lumbar disc protrusion and associated sciatica (T11, N2000/739); and
(ii)5 September 2000, which varied the decision of 12 January 2000 and substituted the decision that the Australian Postal Corporation was not liable to pay compensation to Mrs Field in respect of any injury to the back and associated sciatica arising out of sections 14, 16, 19, 20, 21, 22, 24, 25 and 27 of the Safety, Rehabilitation Compensation Act 1988 (T12, 2000/1521).
A hearing was held in Sydney on 8 and 13 August 2001. Mrs Field provided oral evidence. She was represented by Mr B Slowgrove of Counsel. The Respondent was represented by Ms R Henderson of Counsel. The Tribunal took into evidence documents lodged pursuant to section 37 of the Administrative Appeals Tribunal Act 1975 (T Documents, T1-T23, N2000/739; T1-T15, N2000/1521) and the following exhibits:
Exhibit Number    Description Date
A1      Report of Dr K G Yap, General Practitioner       11 April 2001
A2      Report by Dr P Giblin, Orthopaedic Surgeon     4 October 2000
A3      Report of Dr P Giblin, Orthopaedic Surgeon     7 December 2000
A4      Report of Dr P Conrad, Surgeon 10 October 2000
A5      Report of Dr P Conrad       6 April 2001
A6      Report of Dr P Conrad       24 April 2001
A7      Report of Dr M S Memon, Orthopaedic Surgeon and Supplementary Report         24 October 2000
A8      Report of Dr M S Memon and Supplementary Report 9 April 2001
A9      Job Description, Senior Postal Services Officer, Grade 2, Duties and Special Duties
R1      Photographs from the Australia Post Publication, "All in a Day's Work", page 6 showing Grade Trays and page 7, showing mailbags and trolleys.
R2      Clinical notes of Dr K G Yap, General Practitioner

Issues

The issues in this matter are:
(a)Whether or not Mrs Field suffered an injury or aggravation to her lower back as defined in the Safety, Rehabilitation and Compensation Act 1988;
(b)Whether or not the Respondent is liable to pay weekly payments of compensation beyond 8 October 1999;
(c)Whether or not the Respondent is liable to pay medical treatment and hospital costs beyond 8 October 1999; and
(d)Whether or not Mrs Field sustained a permanent impairment.

Legislation

A decision in this matter requires consideration of the Safety, Rehabilitation and Compensation Act 1988 ("the SRC Act").
Section 4 of the SRC Act deals with interpretation and as relevant states:
"Interpretation
4. (1) In this Act, unless the contrary intention appears:
…
"disease" means:
(a)      any ailment suffered by an employee; or
(b)       the aggravation of any such ailment;
being an ailment or an aggravation that was contributed to in a material degree by the employee's employment by the Commonwealth or a licensed corporation.
…
"injury" means:
(a)      a disease suffered by an employee; or
(b) an injury (other than a disease) suffered by an employee, being a physical or mental injury arising out of, or in the course of, the employee's employment; or
(c) an aggravation of a physical or mental injury (other than a disease) suffered by an employee (whether or not that injury arose out of, or in the course of, the employee's employment), being an aggravation that arose out of, or in the course of, that employment;
but does not include any such disease, injury or aggravation suffered by an employee as a result of reasonable disciplinary action taken against the employee or failure by the employee to obtain a promotion, transfer or benefit in connection with his or her employment.
…"
Section 14 of the SRC Act deals with compensation for injuries and states:
"Compensation for injuries
14. (1) Subject to this Part, Comcare is liable to pay compensation in accordance with this Act in respect of an injury suffered by an employee if the injury results in death, incapacity for work, or impairment.
(2) Compensation is not payable in respect of an injury that is intentionally self-inflicted.
(3) Compensation is not payable in respect of an injury that is caused by the serious and wilful misconduct of the employee but is not intentionally self-inflicted, unless the injury results in death, or serious and permanent impairment.
…"
Section 16 of the SRC Act deals with compensation in respect of medical expenses and as relevant states:
"Compensation in respect of medical expenses etc.
16. (1) Where an employee suffers an injury, Comcare is liable to pay, in respect of the cost of medical treatment obtained in relation to the injury (being treatment that it was reasonable for the employee to obtain in the circumstances), compensation of such amount as Comcare determines is appropriate to that medical treatment.
(2) Subsection (1) applies whether or not the injury results in death, incapacity for work, or impairment.
(3) For the purposes of subsection (1), the cost of medical treatment shall, in a case where the treatment involves the supply, replacement or repair of property used by the employee, be deemed to include any fees or charges paid or payable by the employee to a legally qualified medical practitioner or dentist or other qualified person for a consultation, examination, prescription or other service reasonably required in connection with that supply, replacement or repair.
(4) An amount of compensation payable by Comcare under subsection (1) is payable:
(a) to, or in accordance with the directions of, the employee;
(b) if the employee dies before the compensation is paid and without having paid the cost referred to in subsection (1) and another person, not being the legal personal representative of the employee, has paid that cost—to that other person; or
(c) if that cost has not been paid and the employee, or the legal personal representative of the employee, does not make a claim for the compensation—to the person to whom that cost is payable.
(5) Where a person is liable to pay any cost referred to in subsection (1), any amount paid under subsection (4) to the person to whom that cost is payable is, to the extent of the payment, a discharge of the liability of the first-mentioned person.
…"
Subsection 19 of the SRC Act deals with compensation for injuries resulting in incapacity.
Section 22 of the SRC Act deals with compensation where an employee is in Hospital and as relevant states:
"Compensation where employee is maintained in a hospital
22. (1) Where:
(a) as a result of an injury, an employee (other than an employee to whom section 20, 21 or 21A applies) is maintained as a patient in a hospital, nursing home or similar place and has been so maintained for a continuous period of not less than one year; and
(b) there are no prescribed persons or prescribed children who are dependent on the employee;
Comcare is liable to pay compensation to the employee in respect of the injury of such amount, for each week during which the employee is so maintained, as is determined by Comcare having regard to:
(c) the present and probable future needs and expenses of the employee; and
(d) the period during which the employee is likely to be such a patient;
but the amount so determined shall not be less than one-half of, nor more than, the amount per week of compensation that would have been payable to the employee under section 19, 20, 21 or 21A, as the case requires, had that section applied to the employee.
(2) In this section, prescribed person, in relation to an employee, has the same meaning as in section 19.
…"
Section 24 of the SRC Act deals with injuries resulting in permanent impairment and as relevant states:
"Compensation for injuries resulting in permanent impairment
24. (1) Where an injury to an employee results in a permanent impairment, Comcare is liable to pay compensation to the employee in respect of the injury.
(2) For the purpose of determining whether an impairment is permanent, Comcare shall have regard to:
(a)      the duration of the impairment;
(b)      the likelihood of improvement in the employee's condition;
(c) whether the employee has undertaken all reasonable rehabilitative treatment for the impairment; and
(d)      any other relevant matters.
(3) Subject to this section, the amount of compensation payable to the employee is such amount, as is assessed by Comcare under subsection (4), being an amount not exceeding the maximum amount at the date of the assessment.
(4) The amount assessed by Comcare shall be an amount that is the same percentage of the maximum amount as the percentage determined by Comcare under subsection (5).
(5) Comcare shall determine the degree of permanent impairment of the employee resulting from an injury under the provisions of the approved Guide.
(6) The degree of permanent impairment shall be expressed as a percentage.
(7) Subject to section 25, where Comcare determines that the degree of permanent impairment of the employee is less than 10%, an amount of compensation is not payable to the employee under this section.
…"
Section 27 of the Act deals with compensation for non-economic loss and as relevant states:
"Compensation for non-economic loss
27. (1) Where an injury to an employee results in a permanent impairment and compensation is payable in respect of the injury under section 24, Comcare is liable to pay additional compensation in accordance with this section to the employee in respect of that injury for any non-economic loss suffered by the employee as a result of that injury or impairment.
…"
Section 28 of the SRC Act deals with the Approved Comcare Guide and as relevant states:
"Approved Guide
28. (1) Comcare may, from time to time, prepare a written document, to be called the "Guide to the Assessment of the Degree of Permanent Impairment", setting out:
(a) criteria by reference to which the degree of the permanent impairment of an employee resulting from an injury shall be determined;
(b) criteria by reference to which the degree of non-economic loss suffered by an employee as a result of an injury or impairment shall be determined; and
(c) methods by which the degree of permanent impairment and the degree of non-economic loss, as determined under those criteria, shall be expressed as a percentage.
(2) Comcare may, from time to time, by instrument in writing, vary or revoke the approved Guide.
…"
Background
The following information is provided by way of background and is not disputed:

Mrs Field was born on 15 December 1955.
Mrs Field is employed by Australia Post as a Senior Postal Services Officer and has been employed at Australia Post since January 1992.
On 4 January 2000, Mrs Field completed a claim for Rehabilitation and Compensation in respect of an incident at work which occurred on 15 November 1999. Mrs Field described the injury as "Prolapsed Lumbar Disc with Sciatica, lower back and left leg"(T7, p31- N2000/739).
On 24 December 1999, Dr K G Yap, General Practitioner, provided a medical certificate. Dr Yap noted that the date of the injury was "over several years" and the onset of the complaint was October 1999. The cause of injury was noted as "lifting repeatedly over her years of work with Aust. Post". Mrs Field was certified as unfit for work from 15 November 1999 until 11 January 2000 (T6, p22- N2000/739). Dr Yap reported on 14 February 2000 (T15, p46 - N2000/739), that Mrs Field's lumbar disc protrusion with left sciatica was in his view most likely to have been caused by her years of employment at Australia Post during which time she had lifted repetitively. Dr Yap further reported that it is difficult to prove the cause of an injury when the effects of an activity like lifting become apparent over a considerable period of time. He noted the "cause and effect are not immediately apparent", but in her case, there was no other cause likely to bring on a prolapsed disc. He concluded that Mrs Field's years of lifting at Australia Post were the substantial contributing factor to her injury and that her condition is real and has resulted in her experiencing considerable suffering. He foreshadowed that Mrs Field would have to undergo surgery for her back condition.
On 12 January 2000, the Respondent denied liability in relation to Mrs Field's claim for compensation for lumbar disc protrusion and associated sciatica, determining that she was not eligible for compensation under section 14 of the SRC Act (T11, N2000/739).
On 19 January 2000, Dr P Giblin, Orthopaedic Surgeon, reported that Mrs Field's CT scans suggested "probable stenosis at 5/1" with quite a reasonable degree of suspicion for compression of the L5 nerve root in the foramen at that level. He concluded that Mrs Field's symptoms seemed reasonably causally related to the heavy work that she has had to do (T12, N2000/739). Dr Giblin noted that Mrs Field had had backache for several years but quite severe leg pain for the last four months and considered her to be genuine. A myelogram performed subsequently indicated "significant disc rupture and sequestration on the left side interfering with the left S1 nerve root," (T13, N2000/739). Dr Giblin further reported on 29 February 2000, that Mrs Field had had a left sided L5/S1 discectomy on 15 February 2000. He noted:
"…For the sake of her employer, it should be noted, that it is my opinion that she had a soft tissue injury at work, to the low back at L5/S1 necessitating the surgery which eventuated". (T17, N2000/739).
On 8 March 2000, Mr P Smith of the Reconsideration Section of Australia Post affirmed the decision of a delegate made on 12 January 2000 that Australia Post was not liable to pay compensation for Mrs Field's lumbar disc protrusion and associated sciatica. The Reconsideration Officer considered the opinions of Dr Giblin and Dr Kaur relating to heavy work and years of lifting but noted that those doctors did not mention Mrs Field's outside activities and the raising of three children (T18, N2000/739).
On 27 April 2000, Dr M Gliksman, Occupational Physician, reported that Mrs Field had told him that she had experienced a gradual onset of symptoms two or three years ago, including ache in the left paralumbar region, radiating into the left sacroilial region and the posterior portion of the left lower limb to the ankle, accompanied by lumbar stiffness. Dr Gliksman noted that Mrs Field stated that the onset of symptoms was in the absence of any causal event or events. Dr Gliksman noted that Mrs Field specifically did not recall suffering any work-related injuries or illnesses. The finding on examination and from CT scans indicated age-related and other degenerative changes, rather than trauma, Dr Gliksman concluded. Dr Gliksman opined that Mrs Field should not lift weights greater than five kilograms or participate in tasks requiring repetitive bending or lifting above shoulder height or from below knee height (T21, N2000/739).
On 9 June 2000, Dr P Conrad, Surgeon, reported that Mrs Field was involved in heavy repetitive lifting and bending at Australia Post and loading and unloading trucks with cartons of stock weighing two to three kilograms. The onset was two or three years ago in 1997 or 1998. As a result, Mrs Field sustained an L5/S1 disc protrusion with indentation of the thecal sack and displacement of the S1 nerve root. Dr Conrad noted that despite a discectomy and laminectomy, Mrs Field still had considerable sciatica on the left side and is fit for light work only. Dr Conrad noted Mrs Field was well motivated and continued to work 25 hours per week at Australia Post and was able to continue working providing that she was able to stand or sit at will and not lift anything above five kilograms in weight (T3, N2000/1521).
On 29 June 2000, Dr D Maxwell, Orthopaedic Surgeon, opined that Mrs Field sustained a disc prolapse at L5/S1 and that 50 per cent of such prolapses occur spontaneously without any history of trauma and 50 per cent occur after a specific lifting and twisting injury. Dr Maxwell concluded that he could find no specific incident which precipitated Mrs Field's low back and leg pain. Therefore Mrs Field's disc prolapse had occurred spontaneously. Dr Maxwell opined that the disc may have been degenerate, causing some chronic low back pain and the severe leg pain would have occurred when the disc finally prolapsed. This appears to have been sometime after October 1999. (T5, N2000/1521).
On 26 July 2000, Dr Conrad further reported that according to the Comcare Tables, Table 9.6, Mrs Field has a 10 per cent whole person impairment due to back problems and further, according to Table 9.5, a 10 per cent whole person impairment of the left leg. These impairments combined under Table 14.1 to provide an impairment of 19 per cent (T6, N2000/1521).
On 2 August 2000, Dr Yap, General Practitioner, further reported that it was inconceivable that with seven years of employment at Australia Post during which time Mrs Field was lifting many parcels and pushing mail trolleys, that this work has not contributed to the wear and tear in her back. Although Dr Yap conceded there may be other factors contributing to her condition, Dr Yap concluded that Mrs Field's work was the substantial contributing factor (T7, N2000/1521).
On 5 September 2000, Australia Post varied the Respondent's determination of 12 January 2000, substituting the decision that Australia Post was not liable to pay Mrs Field for compensation in respect of any injury to her back and associated sciatica, specifically under sections 14, 16, 19, 20, 21, 22, 24, 25 and 27 of the SRC Act (T12, N2000/1521).
On 4 October 2000, Dr P Giblin, Orthopaedic Surgeon, opined that Mrs Field had a markedly impaired capacity for work between 8 October 1999 to 22 May 2000 and that she should have been seen to be unfit for her normal pre-injury duties during this period of time (Exhibit A2). Dr Giblin further reported on 7 December 2000, that Mrs Field was still reporting symptoms of backache, sharp stabbing pains and discomfort down her left leg. Dr Giblin noted that Mrs Field was involved in a motor vehicle accident in July 2000, but this accident had no material bearing on her current symptoms (Exhibit A3).
On 24 October 2000, Dr M S Memon, Orthopaedic and Medico-Legal Consultant, reported that as a result of the nature and working conditions of Mrs Field's employment, she developed progressive low back pain. Investigations revealed a disc herniation which was surgically removed. After surgery, Mrs Field had made a good recovery with well-tolerated residual symptoms. Dr Memon noted that Mrs Field experiences increased pain going up and down stairs, steep hills or on prolonged walking but that she had returned to her normal work. He noted there was short-term progress however was concerned that the long term prognosis may not be quite as satisfactory as there is the potential for arthritic change which may be troublesome in the future (Exhibit A7).

On 23 May 2000, Mrs Field made an application for review to the Tribunal (T1, N2000/739) in respect of the Respondent's determination that she was not entitled to compensation for lumbar disc protrusion and associated sciatica.
A further application for review was made by Mrs Field on 4 October 2000 (T1, N2000/1521) in respect of the Respondent's determination that Mrs Field was not entitled to permanent impairment of her back.

Evidence of Mrs Field

Mrs Field told the Tribunal that she commenced work at Australia Post as a cleaner. Her duties at that time included vacuuming, cleaning offices, windows and desks. She also worked in the mail room, where she polished and mopped the floors. Mrs Field worked seven hours and twenty-one minutes over a five-day week.
In 1992, Mrs Field commenced training in the Postal Services area as a "Postal Services Officer." She trained and continued her cleaning duties concurrently. Mrs Field also did relief work during this time in the mail room, collecting mail from the bins. Mrs Field told the Tribunal there was a lot of lifting to shoulder height of bags off/on hooks. She drove a van to local businesses to collect and deliver mail. Other duties involved distributing stock and stationery.
In 1994, Mrs Field ceased cleaning and took up postal service duties on a full-time basis in the "Licence Support Network Office." Mrs Field's duties then included preparing supplies, packaging materials, putting mail into and readying mail bags for dispatch. Mrs Field would drag these mail bags approximately 20 metres to the dispatch chute.
Mrs Field told the Tribunal that in 1994 there was a family tragedy when her son was killed in a motor-vehicle accident. At the time, she was feeling physically fine apart from having to deal with the sudden and devastating loss of her son and all that such a tragedy entailed.
In March 1995, the Post-Office moved from Campbelltown to Liverpool with the merger of two networks. Later, Mrs Field commenced work at the Ingleburn Post Office. Mrs Field was then "Stock and Financial Co-ordinator". Duties at that time involved unloading goods, including boxes of stationery, boxes of post-parcels and rolls. She would unload stock and stores into trolleys 100 metres high or shoulder height. The trolley could fit 24 boxes of photocopying paper and would involve, she estimated, a total weight of approximately 400 kilograms. In terms of loading the trolley, Mrs Field agreed that whoever loaded the trolley decided how much to put on it. Mrs Field could not recall being aware of the 16-kilogram load limit on goods. Nor could she immediately recall seeing goods or mail bags having the "overweight" tag. Mrs Field identified the trolleys to be loaded at page 7 of Exhibit R1. Mrs Field told the Tribunal that she is now familiar with the "overweight" tag and later in evidence recalled that she first saw an "overweight tag" at Ingleburn Post Office in 1999 but did not recall seeing overweight tags in the course of performing her own duties. Mrs Field stated that the goods she dealt with were never weighed. Mrs Field stated that she had not had training about load limits but acknowledged that she would not load goods so that she would be unable to lift them. The trolley was moved then to the storeroom for future use. Mrs Field told the Tribunal that she would order stock and stores and unload once or twice per week, noting that the trucks did not have specific delivery times. There were stores to be put out for delivery every day. For example, Mrs Field noted that she would organise stores for delivery, including reams of A4 paper weighing 12 kilograms per five ream box. Mrs Field estimated that she could load 100 boxes per day and unload 50 boxes or cartons containing a variety of products such as stamps, paper, "post-paks" and the like. Some boxes were heavier than 12 kilograms she believed.
In 1996, Mrs Field participated in an 18-month program in the Sydney Head Office. The aim of this program was to improve the stock management methods in Australia Post. Mrs Field, with a team of people, subsequently prepared a report at the completion of the project. Her work over this period involved working with a team for two months in the city then returning to Ingleburn for two or four weeks. The project was finalised in May 1998. During the periods back at Ingleburn, Mrs Field was a Supervisor with two part-time assistants. The assistants worked on four-hour shifts. Mrs Field would often have assistance, but there were some occasions when she was working alone. If there was an assistant present, Mrs Field had help when loading and unloading. One person would check the stock when it came off the truck, while the other did the more physical duties. Mrs Field estimated that she had assistance for 50 per cent of the time. During this time, she was also dealing with customer complaints.
Mrs Field stated that she only ever worked for a period of two or three weeks full-time in the mail room. If she was in a hurry, Mrs Field would drag bags across the floor and then lift each bag a foot or two into the chute. At the Campbelltown Office, Mrs Field estimated that she would have to drag goods to the chute once or twice per day. At Ingleburn, mail bags were not used as goods were packed into boxes and labelled, then loaded onto the trolley, again similar to that as seen on Exhibit R1, p7. The trolley was then taken 10 metres to the loading area.
In relation to Mrs Field's duties of ordering stock once per week, this took her approximately one hour. She would check stock on hand, then order electronically. When the stock arrived, she would check the order and depending on what assistance was available at the time, she may have had to check and unload the goods herself. There was a full stock-take once per year.
During her intermittent work between the city and Ingleburn Post Office, Mrs Field injured her thumb, but found it difficult to recall exactly when this occurred.
After the Head Office project and in 1999, Mrs Field was working full-time at Australia Post in Ingleburn. She was supervising staff again as the Stock and Financial Co-ordinator. Mrs Field told the Tribunal she was still undertaking the heavy work of loading and unloading reams of paper and putting it onto small trolleys, including taking the trolleys to display areas. Mrs Field acknowledged that in 1999 her work at Australia Post was much less physical.
During 1999, Mrs Field recalled coming home with an aching back and she stated that she probably first noticed this aching in August or September 1999. Mrs Field did not tell anyone about those symptoms as she is not a "whinger". Mrs Field did not see a doctor about her back until October 1999, when it became so bad that she sought medical assistance, attempting to see her General Practitioner, Dr Yap. Dr Yap was away on this first occasion and Mrs Field consulted another doctor, Dr J Gardner (T15, p26, N2000/1521). On 8 October 1999, Dr Gardner certified her unfit for work because of lower back pain until 18 October 1999. It later became apparent in Mrs Field's evidence that the onset of back pain which precipitated her seeing Dr Gardner occurred when she was on recreation leave from work. Mrs Field subsequently had one week of her recreation leave re-credited because of her having to take sick leave in her holidays. Mrs Field stated that when she consulted Dr Gardner, the pain was in her lower back and in her left leg to the ankle. Mrs Field then recalled seeing Dr Yap in November 1999. At that time, the pain was still in her lower back and left leg. Mrs Field stated that although when she first saw Dr Gardner he had given her two weeks off work, she only took one week of sick leave before returning to work. When Mrs Field returned to work, she stated that she was still in pain. It was at that point that she saw Dr Yap in November 1999, and he advised her that she had a "slipped disc" and that she should have a rest for two weeks. After two weeks, Mrs Field was no better and she continued to see Dr Yap on a further three or four occasions before Dr Yap referred her to Dr P Giblin, Orthopaedic Surgeon, in January 2000. Mrs Field told the Tribunal that Dr Yap also referred her to a neurosurgeon, Dr Sheridan.
Mrs Field was referred to medical certificates from Dr Yap for the periods 15 November 1999 up to 3 January 2000. In those documents, Dr Yap referred to "prolapsed (slipped) lumbar disc" but did not refer to any leg pain until the medical certificate of 6 December 1999, in which he referred to a lumbar disc protrusion with sciatica (T15, p30 – N2000/1521).
In her later evidence, Mrs Field noted that during the first week of her holidays in October 1999, she visited her daughter, driving to Port Macquarie, a six-hour drive. Mrs Field stated that she had had pain present for some months before this drive and in recent months had backache and tiredness during the day and after heavy work. The heavy work had started, she stated, in Campbelltown and then in Ingleburn. During the drive to Port Macquarie Mrs Field stated that she was in heavy traffic but she could not remember if her back ached as a result of the long drive.
Mrs Field denied telling her Supervisor, Karen Peacey, that she had woken up on the morning of the drive to Port Macquarie with a backache (T8, N2000/739). Mrs Field recalled telling her Supervisor that she had taken the trip, but she could not recall the details of this conversation or if indeed she had told her Supervisor that the traffic was heavy and the long drive had made her back worse. In response to Ms Henderson's suggestion that the pain came out of the blue on the trip to Port Macquarie, Mrs Field replied "I wouldn't say that". Mrs Field's later evidence was that when she eventually saw Dr Gardner after the Port Macquarie trip, her back pain was worse than in previous months.
Following further questioning, Mrs Field also later told the Tribunal that she had previously seen a chiropractor in 1993 who had "cracked her back". At that time Mrs Field was working at Campbelltown. She did not recall complaining to Dr Yap about back pain in 1995. Further, after questioning, Mrs Field acknowledged that she did have a previous operation for cardiac-arrhythmia and she had to stay still on her back for a long period. Mrs Field did not think that she had any back problems as a result of this. If she had had more back pain than usual, she stated that she would have sought treatment for it.
Under cross-examination and also arising out of questioning from the Tribunal, Mrs Field indicated that there was no particular incident which caused her back pain. She also was not aware of any family history of back problems. There is evidence from doctors that she may have had an aching back in 1998, but Mrs Field stated that the worst pain occurred on holidays in 1999. Mrs Field also later recalled that in May 1999, when she was back at Ingleburn, she had at that stage a problem with an aching back. She was referred to Exhibit A9 concerning her job description which was essentially the same as the inherent requirements of the position contained within the T documents. While Mrs Field had agreed that the work at Ingleburn was lighter, it still involved some bending, lifting and turning duties.
Mrs Field also confirmed later in her evidence that she had moved house in June 1999. She had packed and unpacked the boxes for removal herself but had removalists take them from her former house to her new dwelling. Mrs Field stated that she had no problems as a result of this activity, yet on one of her accounts of her back-pain, this was a period during which she was experiencing back pain.
Mrs Field told the Tribunal that she last worked at Australia Post in 1999 on about 13 November 1999 when she first saw Dr Giblin. He indicated to her that she would require a number of investigations, including a myelogram and he foreshadowed that she may ultimately require surgery. Mrs Field indeed had a laminectomy on 15 February 2000. Prior to the operation, Mrs Field described having pain 24 hours a day and that the pain was on a scale of seven out of ten. It then became worse but after the operation, whilst she still had pain and aches, there had been a 75 per cent improvement. Mrs Field stated that currently, she still has leg pain and occasionally pain and aches in her back, but she now knows how to manage her back pain and is able to restrict her activities in order to ensure that she does not cause herself more pain. Mrs Field stated that she has learnt about and accepted her restrictions. The pain level now is on a scale of three out of ten, whereas just prior to the operation it was on a scale of 10 out of 10.
Prior to November 1999, Mrs Field was earning $1,150.00 per fortnight but from November 1999 until May 2000 she was not in receipt of any compensation. During her period of work following the operation, Mrs Field took three months sick leave, four weeks recreation leave and three months with no pay.
In May 2000, Mrs Field commenced working part-time four hours per day. At that stage, she was still taking a great deal of "Panadeine" medication, but was working on counter duties. Mrs Field's gradual return to work included working four hours per day for two weeks, five hours per day for two weeks and then six hours per day for two weeks, until she returned to full duties in July 2000.
Mrs Field told the Tribunal that her lifestyle changed considerably as a result of her back problems. In early 1999, Mrs Field was involved in many social and recreational activities. She was a sports person. When she ceased work in October 1999, Mrs Field could not do much at all, either by way of sporting or recreational activity or work around the house. The pain in her back interfered greatly with her social life. Specifically, Mrs Field told the Tribunal that she had commenced a relationship in 1999 but had told her companion that he should leave because she was in so much pain and did not know what was happening. Fortunately, for Mrs Field, her companion stayed with her. Mrs Field also told the Tribunal that she used to dance before the operation but stopped that in September or October 1999.
Mrs Field's current work situation is that she is Acting Postal Manager and at the time of Hearing, did not know when this might end. Mrs Field was hoping to secure a permanent position as Postal Manager.
Mrs Field described her current level of disability as having an aching/sore back, but not to the level before her operation in February 2000. She also had a burning sensation in her back and left leg prior to the operation but did not have this now.
During her presence at the hearing, Mrs Field described her pain as being in the order of six or seven out of ten, principally because she was sitting for such a long time. It was an aching rather than a burning pain, she stated. Mrs Field told the Tribunal that she has good and bad days. Her pain is mostly between one and five out of ten and perhaps once per week, it is at the level of one out of ten. In relation to her left leg pain, Mrs Field described this as a dull ache. At home, Mrs Field stated that as at work, she is careful in what she does. Mrs Field still drives a car, hangs out the washing herself and lifts and bends in her private life. Her back condition has no impact on her ability to walk. Mrs Field now knows, she told the Tribunal, not to do the lifting she was previously undertaking at work. Mrs Field told the Tribunal that she has four children but had healthy pregnancies with no back pain.
Various medical records do detail muscular back problems for years which eventually increased to severe levels with the culmination on holidays in October 1999. Mrs Field stated that whilst this might be true, she had ignored the problem until she thought that she really did need to see the doctor, which she did in October 1999.
Evidence of Dr D Maxwell, Orthopaedic Surgeon
Dr Maxwell told the Tribunal that he examined Mrs Field on 29 June 2000 and provided a report dated 29 June 2000 (T5, N2000/1520). Dr Maxwell noted that when he did his report, he had the benefit of Dr Giblin's report of 10 August 2000 (T9, N2000/1521).
Dr Maxwell noted that Mrs Field described low back pain at the end of the day after a days work, but he could not identify a specific cause. Dr Maxwell considered the pain to be muscular pain from fatigue and noted that occasionally before a disc prolapse, it can cause low backache, which is often not incapacitating. Usually, the pain associated with prolapse occurs because the prolapse is pressing on the adjacent nerve root causing sciatic-type pain which then radiates down the buttock and knee. Such pain is usually unilateral following a certain dermatomal distribution. Dr Maxwell confirmed that Mrs Field had not reported to him any history of sciatica at work. Dr Maxwell noted that the muscular type pain which he believed Mrs Field was describing to him at the end of the day was different in character to pain associated with prolapse. The latter pain is often associated with other affects on the nerve, such as weakness of the muscles or loss of sensation. The pain associated with prolapse is a more intense pain, more continuous and may be affected by different activities.
Dr Maxwell knew that Mrs Field's duties included bending and lifting, but he ruled out the nature and conditions of her work causing the development of a disc problem because the more severe pain she described occurred when she was on holidays. It was at that time that Mrs Field first sought medical attention. Dr Maxwell concluded that the actual disc prolapse had occurred while she was not at work. In this regard, Dr Maxwell noted that Mrs Field gave a history of a long drive and that it was from that point that she seemed to develop severe leg pain. Dr Maxwell further noted that about half the disc prolapses will occur without any history of injury and the other half will occur at a specific time, often associated with a lifting injury. Therefore spontaneous disc protrusions do occur.
Mr Slowgrove, for the Applicant, asked Dr Maxwell about disc protrusions which Dr Maxwell stated are soft tissue injuries. In relation to such injuries, Dr Maxwell opined that jobs involving prolonged sitting seemed to be more of a risk with causing disc protrusions than jobs where people are active. Accordingly, Dr Maxwell did not think that low-grade activity, which he considered Mrs Field's duties to be, could be regarded as a likely cause of disc disease or disc protrusion. Mr Slowgrove further questioned Dr Maxwell as to whether or not, if Mrs Field had low-grade back pain from the job she did at work, whether she could still have a disc prolapse while on holidays and clinically, whether that could stem from her work. Dr Maxwell replied that if Mrs Field had a disc prolapse with a lifting incident at work, it would be work related. In reality however, there was a very grey area when there was a disc protrusion which had occurred away from work, or if it occurred gradually over a period of time, without specific incident. Dr Maxwell agreed with the proposition that because Mrs Field had a disc prolapse while on recreation leave, then it was a grey area as to whether or not there could be a causal relationship with work. Dr Maxwell noted that typically, people who have a disc prolapse state that they have had about one or two years of a very low grade back pain which is probably due to the disc degenerating. This pain could confused by either Medical Practitioners or the patient as muscular pain.
Dr Maxwell told the Tribunal that he disputed Dr Giblin's conclusion of a work-related disc prolapse which was based on his understanding of Mrs Field's job requirements of bending, lifting and twisting, and on the basis that her symptoms commenced at work (T9, p18 - N2000/1521). Dr Giblin's conclusion was that Mrs Field had the provisional diagnosis of a soft tissue injury to her back with resultant sciatica, "reasonably causally related to her work environment". Dr Maxwell stated that he disagreed with Dr Giblin on the basis that he had no knowledge of Mrs Field having any sciatic pain prior to disc prolapse when she was on holidays. In addition to the assumption which Dr Giblin made, that Mrs Field's back pain was directly related to work, Dr Maxwell's impression, from Mrs Field's statements to him, was that the backpain was bad at home when she was resting and this did not necessarily mean that it was due to her work. Dr Maxwell's point was that the pain may have come on whether or not Mrs Field was working. Dr Maxwell further noted Mr Slowgrove's submission that the pain did not come on one particular day, but, on Mrs Field's evidence, was happening continually. Dr Maxwell acknowledged that Mrs Field indicated to him that the pain was a chronic thing but she made no mention that it was worse after a day's work more so than it was on a weekend, although this was not directly discussed in any great detail. The presence of sciatic pain, Dr Maxwell noted, directly related to the rupture in the disc. It was at that point where there was nerve root irritation which radiated down Mrs Field's left leg. Sciatic pain was not reported to Dr Maxwell as being present until after October 1999.

Dr Maxwell noted that in his report he had placed restrictions on Mrs Field's activities after surgery. He did not agree that this suggested that her work was having an effect on her back. Dr Maxwell explained that because Mrs Field had had an operation as a result of a disc prolapse, she needed to take care following the prolapse and the operation.
In relation to Dr Maxwell's assessment in his report that Mrs Field had a ten per cent permanent impairment (not causally related to work), representing a loss of half the normal range of movement, he noted that the evidence was that Mrs Field could reach to her calves. Accordingly, at hearing, Dr Maxwell reassessed the impairment, noting that the more accurate impairment was five per cent whole person impairment. He noted that Mrs Field does not have a great deal of restriction on walking, standing or climbing stairs.
Dr M S Memon, an Orthopaedic Surgeon, had noted that Mrs Field had a slight scoliosis. Dr Maxwell opined that this was not likely to cause pain.
Dr Maxwell concluded that there is some difficulty in making a decision about the cause of Mrs Field's back problem. In this regard, Dr Maxwell opined that it is very hard to relate work environments to disc degeneration and that this can occur in anybody at any time. In his experience, usually people whose discs are degenerating do experience some low backache, but it is very hard to actually suggest which occupations will lead to that. Certainly, people with more sedentary occupations have a higher rate of disc degeneration and subsequently a disc prolapse compared to those who are physically active. In other words, Dr Maxwell opined that physical activity helps protect the disc. Dr Maxwell had examined Mrs Field, spoken to her and had documents available including the inherent aspects of her position. Sometimes a prolapse can occur with a lifting incident and sometimes as Dr Maxwell had previously stated, in about half of the cases it comes on with no specific injury. The difficulty is deciding when work has actually caused the disc to degenerate prior to it prolapsing. In Mrs Field's case, Dr Maxwell concluded that it was very hard to make this causal connection, given the nature and conditions of her work as he understood them from talking to Mrs Field and considering her job description and requirements.
Dr Maxwell conceded that in relation to the various investigations undertaken of Mrs Field's back, including the CT scans, there was no significant degeneration of the facet joints. Having said this, Dr Maxwell noted that it would be unusual for someone who was "cooking up a disc for two years" not to see that on scan. However, Dr Maxwell noted that disc protrusions usually occur in the age group of 35 to 50 years and these are the people that tend not to have significant degenerative changes, Dr Maxwell stated.
In relation to Mrs Field's driving trip to Port Macquarie, Dr Maxwell opined that it was difficult to conclude that the drive was a cause, but in his view, it seemed to have contributed to the prolapse. Dr Maxwell noted that it is not an uncommon history to hear of somebody going on a long drive and developing a disc protrusion. Further, generally it is found that people who are unfit have a high incidence of disc protrusion because they have poor tone in their trunk muscles and it is the trunk muscles which protect their disc. In Mrs Field's case, the activity she was undertaking at work would probably protect her back because she was not sitting down all day, she was moving about, using her back bending and stooping and lifting reasonably light weights but on occasion, heavier weights.
It is Dr Maxwell's position that Mrs Field had some internal changes occurring in the disc which was related to degeneration as she got older. Occasionally, part of the disc degenerates and this then caused a protrusion through the degenerate area. Dr Maxwell did not agree with Mr Slowgrove's proposition that applying Dr Maxwell's theory, anyone who experienced consistent low grade back pain after work or at work doing a job involving bending and lifting could never show that their job caused the problem. Dr Maxwell stated that most people who injured their back at work have a specific injury. In most cases, the proposition that a back injury is work-related through the nature and conditions of work is fallacious, without there being a specific incident. This is Dr Maxwell's firm opinion based on the balance of probabilities.
Recent Medical Evidence
Dr P Conrad, Orthopaedic Surgeon
Dr Conrad provided more recent reports dated 6 April 2001 (Exhibit A5) and 24 April 2001 (Exhibit A6). On 6 April 2001, Dr Conrad opined that due to heavy, repetitive lifting and bending at Australia Post, Mrs Field developed L5/S1 disc protrusion and that despite laminectomy has ongoing backache and left sided sciatica. Dr Conrad concluded that according to the Comcare Tables, Table 9.6, Mrs Field has a ten per cent whole person impairment due to her back and from Table 9.5, a ten per cent whole person impairment due to left sided sciatica. This provided a combined impairment from Table 14.1 of 19 per cent.
Dr Conrad's report of 24 April 2001 reiterated his previous conclusions contained in the earlier report of 6 April 2001.
Dr M S Memon, Orthopaedic and Medico-Legal Consultant

On 9 April 2001, Dr Memon noted on clinical examination of Mrs Field's lumbar spine that she has a well healed mid-line scar and slight scoliosis with mild tenderness over L5/S1. Reflexes were normal but sensations were diminished over the left thigh and leg. Dr Memon noted left quadriceps wasting by 0.5 centimetres. (Exhibit A8).
Dr Memon reported on 24 October 2000, that as the result of the nature and conditions of Mrs Field's employment, she has 28 per cent whole person impairment as per the Comcare Guidelines, Tables 9.5 and 9.6.
Dr K G Yap, General Practitioner
On 11 April 2001, Dr Yap further reported that Mrs Field's seven years of employment at Australia Post was a substantial contributing factor to her ruptured lumbar disc. Dr Yap noted that Mrs Field will have to continue back exercises indefinitely and must be "obsessively cautious" in any activity. Dr Yap noted that there was a risk that Mrs Field would suffer further back pain and disability because of the effects of her compromising the integrity of the spine from a ruptured lumbar disc (Exhibit A1).
Submissions
Mr Slowgrove, for the Applicant, submitted that this case narrows down to the essential proposition that the Tribunal could either accept Dr Maxwell's opinion that there is no causal connection between employment and Mrs Field's condition or in the alternative, that employment did make a substantial contribution to Mrs Field's condition. Mr Slowgrove contended that there is no medical dispute that Mrs Field has a disc problem. Further, Mr Slowgrove strongly submitted that there is no issue in relation to Mrs Field's credit.
Mr Slowgrove submitted that there is a problem with Dr Maxwell's opinion. Dr Maxwell concluded that because the disc problem occurred away from work and there was therefore no temporal connection with work, then in Dr Maxwell's view, there could be no causal connection. Clearly, Mrs Field was not at work when the prolapse occurred, Mr Slowgrove noted. Put simply, Mr Slowgrove submitted that Dr Maxwell's view is that in the circumstances of Mrs Field's case, it is not possible to have a soft tissue injury to the back that arises from the nature and conditions of employment. Mr Slowgrove further submitted that Dr Maxwell's opinion was that if there was soft tissue back pain, even of a low grade nature, while Mrs Field was at work for a considerable period of time, this could not be work–related.
Mr Slowgrove noted that Dr Maxwell's assessment of the evidence includes his consideration that the prolapse did not occur at work and that Dr Maxwell's understanding of Mrs Field's evidence was that she did not experience sciatica at work. It was basically these two factors that were the basis for Dr Maxwell's disagreement with Dr Giblin's opinion. Mr Slowgrove further contended that Dr Maxwell's conclusions are based on it not being possible to prove a work- related causal connection with Mrs Field's back condition. Not even on the balance of probabilities was Dr Maxwell able to conclude a work relationship between Mrs Field's back condition and work, despite his statement that Mrs Field's circumstances fall within a "gray area" in terms of causation. Dr Maxwell's position is extraordinary, Mr Slowgrove submitted, because, in his submission, compensation cases like this occur all the time and such cases often succeed. If the Tribunal accepted Dr Maxwell's opinion, then in Mr Slowgrove's submission, nature and conditions claims for compensation for low grade back pain followed by disc prolapse could never succeed and the Tribunal's work on such matters would be halved. Dr Maxwell's evidence in its totality would make it very difficult to ever prove the case that in regard to backs and disc prolapses, they could ever be found to be work related, Mr Slowgrove submitted. Dr Giblin is the best placed of all the doctors in this matter to provide an opinion, Mr Slowgrove contended.
Mr Slowgrove submitted to the Tribunal that he did not have to prove as a matter of certainty that Mrs Field's disc prolapse arose out of employment. Mr Slowgrove has to show that on the balance of probabilities, it is more probable than not that the employment was a substantial contributing factor towards the disc prolapse. This proposition was supported through Dr Giblin's various reports. Mr Slowgrove submitted that given the standard of proof required in compensation matters, Dr Maxwell's opinion collapses on an evidentiary basis.
While the Applicant concedes that the disc prolapse did not happen at work, reliance is placed on Dr Giblin's opinion that the prolapse is work-related. Mr Slowgrove submitted that Dr Giblin's view should be accepted by the Tribunal because he is Mrs Field's treating specialist. Dr Giblin carried out Mrs Field's laminectomy and he has all of the history. Mr Slowgrove contended that given Dr Giblin's experience and dealing with Mrs Field, his opinions are more informed and persuasive.
Mr Slowgrove submitted that arising out of Dr Maxwell's evidence was the proposition that low grade back pain which Mrs Field felt prior to the disc prolapse may have been as a result of the back degenerating, that is, it may have been discogenic pain. The problem with that opinion is that none of the radiological reports support such a view and Dr Maxwell admitted this in evidence.
Mr Slowgrove submitted that Mrs Field's evidence is that she had back pain starting continuously in July 1999 and it may have even been present as early as May 1999. At the end of the day, Mr Slowgrove contended that it is not possible to say as a matter of certainty that the disc prolapse was caused by work or not caused by work. Simply put, in Mr Slowgrove's submission it was more probable than not that work substantially contributed to Mrs Field's back problems.
Referring to Dr Yap's opinion, Mr Slowgrove contended that he makes it clear that it is Mrs Field's work which has caused her back problems. Dr Yap is thus in agreement with Dr Giblin, Dr Conrad and Dr Memon. Dr Maxwell is therefore at odds with other medical opinion and has a thesis of his own which none of the other doctors subscribe to, Mr Slowgrove submitted. There is nothing to indicate that Mrs Field had abnormal degenerative changes in her back. It further does not follow, Mr Slowgrove submitted, that there can be therefore no connection between the soft tissue injury to the back and a disc prolapse.
Referring specifically to Mrs Field's work duties, Mr Slowgrove submitted that it is quite clear that Mrs Field's job, as a practical reality, required her to do physical lifting and bending. Mr Slowgrove further asked the Tribunal to accept that she had to turn as part of the performance of her duties and that from medical reports, this involved twisting. Furthermore, Mr Slowgrove asked the Tribunal to accept that Mrs Field experienced low back pain while she was doing that sort of work in the day and after work. What is also important for the Tribunal to understand is that Mrs Field experienced the pain continually, Mr Slowgrove submitted. It was not a one off occurrence but everyday. In her mind, Mrs Field associated her work activity with the pain she experienced and she complained to doctors along those lines.
Even if the Tribunal concluded that driving to Port Macquarie put some pressure on Mrs Field's back, that did not stop her back condition being work related because of other factors. On the balance of probabilities, Mr Slowgrove submitted that her work substantially contributed to Mrs Field's back condition and accordingly, she had discharged her onus. From the inherent requirements of her position described at T4, p9 (N2000/1521), Mr Slowgrove submitted that Mrs Field's duties included being required to bend, to lift, to turn and to twist and her evidence is that she experienced back pain contemporaneous with those duties on a consistent basis. Mr Slowgrove contended that Dr Giblin, Dr Memon, Dr Conrad and Dr Yap had provided the same history as Dr Maxwell. Not one of those doctors thought that because Mrs Field had a disc prolapse when she was on recreation leave, that that prevented her employment having a causal link with her condition.
In relation to the assessment of Mrs Field's impairment level, Mr Slowgrove submitted that the assessment as provided by Dr Giblin, her treating specialist, should be accepted. Mr Slowgrove further submitted that Dr Maxwell's evidence did not diminish Dr Giblin's opinions. Dr Maxwell's opinion was seized upon by the Respondent in an attempt to use a fortuitous circumstance that Mrs Field had a disc prolapse when she was on a period of recreation leave, to try and take it out of the course of employment.
Mr Slowgrove submitted that Mrs Field has a 50 per cent whole person impairment. What is also at issue is the pain and suffering experienced by Mrs Field. The pain and suffering experienced by Mrs Field is significant, causing fundamental interference with her life.
In relation to Dr Maxwell's opinion that Mrs Field's work duties may have protected her back, Mr Slowgrove submitted that Mrs Field still developed pain whilst she was doing her work. How could it be that work would have been protecting her disc when she was developing continuous back pain at work and after work, Mr Slowgrove asked? The fact that Mrs Field was in pain meant that the work was not protecting the disc, Mr Slowgrove contended.
Ms Henderson, for the Respondent, submitted that while Mr Slowgrove had noted on a number of occasions that his client's credibility was not undisturbed, the respondent did not hold such a view. Ms Henderson provided the Tribunal with a number of examples where Mrs Field had provided seemingly inconsistent evidence. Mrs Field told the Tribunal that in 1999 she was at Ingleburn as a Supervisor of staff undertaking counter duties. Her title was "Stock and Financial Coordinator". Ms Henderson contended that in fact Mrs Field was second-in-charge of the Post Office. Mrs Field had initially told the Tribunal that her duties were physical and she was still putting copy paper on trolleys and onto displays, receiving stock. She later provided evidence that the work was much less physical than she had been doing previously. Then, Mrs Field stated that in July 1999, she had a tired aching back at the end of the day. Mrs Field had also told the Tribunal that she first noticed her aching back in about August or September 1999. Further evidence had Mrs Field indicating that she experienced pain in the left leg located slightly to the left of the spine and down the back of that leg. Mrs Field recalled that Dr Gardner was the first General Practitioner she saw for back pain and he told her that her condition was muscular. Thus, Mrs Field's evidence was that she first noticed her aching back in August or September 1999 and at that stage she was working when she saw Dr Gardner. Under cross-examination, Ms Henderson reminded Mrs Field that she had experienced back pain which took her to Dr Gardner whilst she was on recreation leave (as noted in the T documents) from 27 September until 29 October 1999. At that point, Mrs Field's evidence was that she in fact had the pain before she went on holidays and that it had been there for a few months before, that is, present a few months before August or September.
Ms Henderson noted that further questioning from the Tribunal provided evidence Mrs Field that in fact she had an aching back present when she was at Ingleburn in 1998 loading trucks. Summarising Mrs Field's evidence, Ms Henderson noted that it included histories which had back pain commencing in August to September 1999, a few months before her September/October holidays, and, in 1998. Dr Memon's report of 24 October 2000 (Exhibit A7), then dated the onset of Mrs Field's pain four years before he saw her, which takes the onset even further back than any of her three versions provided to the Tribunal by Mrs Field at Hearing.
Ms Henderson concluded that in the Respondent's submission, Mrs Field is a very poor historian and has very little ability to accurately relate events. Mrs Field's poor historical perspective was further illustrated when Mr Slowgrove had reminded Mrs Field that she had had a thumb injury and that Mrs Field had told the Tribunal that this happened while she was under training when she was working as a cleaner. It was later pointed out that in fact the thumb injury occurred in 1998 and Mrs Field was "visibly surprised". Ms Henderson submitted that Mrs Field was just as surprised during the Hearing when she was reminded that it was on her holiday that she sustained a disc prolapse.
Ms Henderson submitted that against the variety of histories provided by Mrs Field, it is important to reflect on what is known for sure about the disc prolapse. Mrs Field was on holidays from 27 September to 29 October 1999. The trip that she made to Port Macquarie occurred on the October long weekend. Mrs Field saw Dr Gardner as the first medical practitioner she ever consulted for back pain on 8 October 1999. When Mrs Field gave Dr Gardner's certificate to her supervisor, Ms Peacey, the supervisor noted that she had never previously been informed of any injury to Ms Field except when she bought in Dr Gardner's certificate (T8, p36 N2000/739). Ms Peacey had reported that Mrs Field told her that she had woken up with a sore back and that she drove to Port Macquarie in bad traffic, taking six hours to reach her destination. Further, it was reported that Mrs Field told Ms Peacey that the prolonged sitting had made it worse. Ms Henderson noted that Mrs Field had agreed with the details in Ms Peacey's note under cross-examination, apart from denying she had woken up with a sore back.
Ms Henderson submitted that Mrs Field's memory was also deficient in that she thought that she had first seen Dr Yap in November 1999 although Dr Yap has an entry in his medical notes of seeing her on 13 October 1999. At that time, Dr Yap noted Mrs Field's back pain was greater than when seen by Dr Gardner last week and Dr Yap opined that Mrs Field had ligamentous strain. On Mrs Field's own evidence, she did not at the time associate her back condition with work. It was only when she saw a doctor in a medical centre who suggested this possibility that this became focussed in Mrs Field's mind, Ms Henderson contended. Dr Yap did not disclose to Mrs Field the prospect which Dr Maxwell had explained, that constitutional processes can lead to prolapsed discs which happen to 50 per cent of the cases quite spontaneously.

Ms Henderson submitted that even if the Tribunal accepted that Mrs Field had back pain at the end of her day's duties prior to October 1999 when she consulted Dr Gardner and later Dr Yap and Dr Giblin, it was still apparent that Mrs Field described the pain when first examined as pain that she did not mention to anyone previously because she thought it was insignificant. Ms Henderson noted Dr Yap's treatment cards, where it is mentioned from time to time that Mrs Field did tell the doctor of back pain. This was never recorded as being in the context of her work. For example, in March 1998 the medical records noted that Mrs Field associated a period of back pain with an operation which she had had to correct a cardiac arrhythmia which had been troubling her. On another occasion in March 1992, Mrs Field complained to Dr Yap of neck and upper back pain which she experienced while stretching in bed. In July 1993, back pain was recorded arising out of Mrs Field's bad posture while watching a video. Ms Henderson contended that Dr Yap's medical records are evidence that it was not a matter of insignificance to Mrs Field that she actually experienced back pain at times which caused her to consult with her General Practitioner. Ms Henderson further referred the Tribunal to Mrs Field's evidence that she had moved during mid 1999 and that while removalists had carried boxes of her belongings and furniture from one dwelling to the other, she had packed and unpacked her own boxes. She could not remember any specific problems with her back at the time. This is curious given Mr Slowgrove's submission on the history that at that stage in 1999, Mrs Field was experiencing continuous problems with her back.
Referring to the medical opinions available in this case, Ms Henderson noted that Dr Conrad had the onset of Mrs Field's back pain as occurring two or three years ago. Dr Giblin was told that there was backache for several years. Dr Yap stated that she first presented to him on 13 October 1999 with low back pain of a week's duration. There is therefore a great spread of different versions which Mrs Field has given or various doctors have understood her to have given as to the onset of her back problems. In particular, Dr Yap did not receive any complaints and accounts of difficulty that Mrs Field was having at work. Ms Henderson contended therefore that the Tribunal should regard all those various histories as indicative that Mrs Field was suffering minor muscular ligamentous sorts of problems such as might be experienced by anyone from time to time at the end of the day's work. The Tribunal should not, as Dr Maxwell had opined, move to the conclusion that work then was actually causing damage to the spine.
Specifically in relation to Dr Giblin, whose opinion Mr Slowgrove submitted should be persuasive on the Tribunal, Ms Henderson submitted that the Tribunal should carefully consider the history reported by Dr Giblin. On 19 January 2000, Dr Giblin referred to Mrs Field as having backache for several years and quite severe leg pain for the last four months (T12, N2000/739). On 31 January 2001, Dr Giblin referred to Mrs Field's CT results and further noted that Mrs Field wished to put the matter through Workers Compensation (T13, N2000/739). On 29 February 2000, Dr Giblin noted that it is his opinion that Mrs Field had a soft tissue injury at work (T17, N2000/739). On 28 March 2000, post operatively, Dr Giblin predicted Mrs Field's ability to return to lighter work (T19, N2000/739). On 10 August 2000, Dr Giblin reported that on the basis of Mrs Field's job, requiring bending, lifting and twisting and on the basis that her symptoms commenced at work, he gave the provisional diagnosis of a soft tissue injury to her back with resultant sciatica "reasonably causally related to her work environment" (T9, p18, N2000/1521). Dr Giblin then concluded that Mrs Field has a 15 per cent whole person impairment from Table 9.6 of the Comcare Guide. Dr Giblin's report of 4 October 2000 (Exhibit A2) states that Mrs Field is probably unfit for work during the period 8 October 1999 to 22 May 2000. Dr Giblin further reports on 7 December 2000 (Exhibit A3) about Mrs Field's motor vehicle accident.
From all this material, Ms Henderson noted that Mr Slowgrove was submitting that Dr Giblin had all the histories. Mrs Field's own evidence did not refer to any twisting that she was required to do in her duties. Dr Giblin in his longer report at T9, p18 - N2000/1521 gave no indication whatsoever, Ms Henderson submitted, as to why Mrs Field was required to bend or twist and also did not indicate how often this occurred. It also appears quite clear from T9 - N2000/1521 that Dr Giblin had no idea that Mrs Field's symptoms did not commence at work but rather in the middle of a one-month's holiday. Ms Henderson submitted that the Tribunal is in a vastly better position than Dr Giblin to understand what was involved in the bending and lifting and other duties undertaken by Mrs Field. Ms Henderson submitted that far from ruling out the significance of a holiday, the Tribunal could not be satisfied that any of the medical practitioners whose reports are relied upon by the Applicant had ever heard that piece of history. As to Mrs Field's supposed long history of heavy lifting, Ms Henderson submitted that Mrs Field's evidence was that she worked in a mail room actually handling mail bags on a regular basis for only two or three weeks out of her lengthy Australia Post career.
Ms Henderson referred the Tribunal to Mrs Field's denial of any previous health problems prior to the year 1997 during her examination-in-chief. In the duties which she had described from that period onwards, she had available to her help from other staff. Mrs Field had agreed that it was up to her how much she piled on to the trolleys and which she might have to move on her own. Mrs Field also readily spoke of the scenario in which two people would work together. Thus, Ms Henderson contended that Mrs Field's major responsibility in the period since 1997 has been the distribution of goods to licensed Post Offices and those Australian Post Outlets staffed and run by non-Australia Post personnel. It was Mrs Field's task to go through the orders put in by the numerous licensed Post Offices and to load into a box with her two assistants the required Australia Post Items, including stationery needed to replenish the local Post Office's supplies.
Mrs Field also explained that none of the outgoing boxes would weigh over 16 kilograms and that it would be most unusual for them to be over 12 kilograms. Under no circumstances, according to Mrs Field's evidence to the Tribunal, did she pack boxes so heavily that she could not lift them, Ms Henderson submitted. The protocol for handling the bags or boxes was first established when she was at Campbelltown. In that location the boxes were loaded into bags then pushed down a chute. They had first been dragged about 20 metres along the floor which was partly carpeted and partly shiny. At Ingleburn however, goods were loaded onto a trolley as identified by Mrs Field. Ms Henderson noted that Mrs Field did not represent to the Tribunal that that particular task was the only duty she was required to perform. Mrs Field had also told the Tribunal that she never had to interrupt her work because of her suffering back pain or of having to take a break to recover. Ms Henderson contended that Mrs Field's apparent description to Dr Giblin of a job which consisted of bending, lifting and twisting compares very poorly to the very detailed understanding which the Tribunal had obtained during the Hearing as to the types of duties that Mrs Field was performing.
Ms Henderson next referred to Dr Memon's reports in which he recorded a brief history that at work, Mrs Field was lifting boxes of various sizes and weights. Again, this history compares very poorly with the evidence provided at Hearing. Dr Conrad believed that Mrs Field's job involved lifting mail bags and various items of stock which were relatively heavy. The job entailed a lot of lifting and bending. In the Respondent's submission, the histories contained in the Applicant's various medical reports do not reflect a great deal of understanding by those doctors of Mrs Field's actual duties and work circumstances. Ms Henderson stressed that Mrs Field has not represented the lifting which she was required to do as being particularly heavy, nor does it seem that the medical practitioners who formed these views had an understanding of what assistance was available to Mrs Field in terms of fellow employees. While Mr Slowgrove stressed that none of the Applicant's doctors expressed any reservations about the fact that Mrs Field's back condition was work caused, in the Respondent's submission, none of those medical practitioners were in a position comparable with the Tribunal in terms of evaluating the duties performed by Mrs Field and in understanding the job requirements. Further, none of those medical practitioners seemed to have the benefit of the knowledge that the prolapse actually manifested itself in the middle of a month's holiday.
In contrast to the medical opinion provided by experts engaged by the Applicant, Ms Henderson submitted that Dr Maxwell gave evidence which was careful. The test that the Tribunal is required to apply is a test of evaluating the expertise of the doctors and the credibility of the expert evidence which had been provided to the Tribunal. Dr Maxwell explained that the pain which Mrs Field experienced prior to her disc prolapse could be consistent either with muscular discomfort at the end of a day's work or the slow process of the collapse in a degenerative disc. Dr Maxwell firmly refused, for credible reasons, Ms Henderson submitted, to agree to the further possibility that it was the work duties which were causing the ultimate prolapse of the disc. Ms Henderson further submitted that the Tribunal should accept as credible Dr Maxwell's opinion that the use of back muscles and actually exercising the back serves to protect and delay the onset of disc prolapse. Dr Maxwell relied on medical literature and on his own clinical experience and expertise in providing his opinion. Dr Maxwell pointed out that the literature indicates that it is more the sedentary occupations which increase the rate of risk of disc prolapse and that physical activity in work duties appears to assist persons who are at risk of prolapse. Where Dr Maxwell was relying on his own personal experience or views he made that quite clear, Ms Henderson submitted. While it was hard to say whether the motor vehicle trip to Port Macquarie caused the prolapse, Dr Maxwell noted that it was not an uncommon history that patients who had undertaken a long car drive later experienced a disc prolapse. Dr Maxwell did not know whether his clinical experience was supported in the literature. Dr Maxwell was not shaken in cross-examination, Ms Henderson submitted and he was an impressive and credible witness. Dr Maxwell's explanation of the Applicant's situation is in line with statistical evidence that a spontaneous disc prolapse occurs as a 50 per cent likelihood in the population. This is a convincing opinion which, in Mrs Field's case, is supported by the evidence, Ms Henderson contended.
If the Tribunal did not accept the Respondent's submissions on this point, then in relation to the matter of permanent impairment, Ms Henderson noted that the medical practitioners for the Applicant are at variance with one another in relation to the issue of assessment of the impairment. Ms Henderson noted that Dr Memon and Dr Giblin were at variance in their reports and while Dr Maxwell's findings were not markedly different from those of Dr Giblin and Dr Memon, Ms Henderson submitted that the appropriate rating is five per cent as found by Dr Maxwell. One of the Applicant's medical practitioners suggested there existed impairment also under Table 9.5 of the Comcare Guide in the range of 10 per cent but that Table refers to a person who can rise to a standing position and walk but has difficulty with grades and steps. Ms Henderson submitted that here was no such evidence provided by Mrs Field. On the evidence provided to the Tribunal, in terms of the affects on Mrs Field's day to day activities, be that at work or domestically, there was no support for the contentions of medical practitioners who had assessed Mrs Field as having a 10 per cent impairment under Table 9.5 or indeed Table 9.6, Ms Henderson contended.
Ms Henderson concluded in relation to permanent impairment that if the Tribunal accepted that Mrs Field had a work related back injury, the most that could be assessed in terms of permanent impairment was five per cent under Table 9.5, because the necessary restriction on physical movement has not been reported by Mrs Field to any practitioner nor to the Tribunal. Ms Henderson reiterated the Respondent's principal submission, however, that the Tribunal could not be satisfied as to a causal connection between the back prolapse and the nature and conditions of the work Mrs Field was doing during her many years of service with Australia Post.
Findings
The Tribunal has reached a decision in this matter taking into account the oral and documentary evidence of the legislation and case law.
A fundamental difficulty in this matter is the variation in evidence provided to the Tribunal by Mrs Field and medical experts as to the history of her lumbar back condition and sciatica of the left leg. The Tribunal has evidence of a variety of onset dates of the back symptoms. In this regard, the Tribunal notes that Mrs Field is reported to have experienced lower backache and pain commencing in August/September 1999; some months prior to August/September 1999; 1998; 1996 and, in 1994. It is apparent that it is not only the Tribunal which has been provided with varying histories, but also the medical experts on whose opinions the Tribunal had been urged to rely. It is also apparent from reading the various medical practitioners' reports, that the majority believed that the onset of the prolapsed disc occurred at work, when in fact, it occurred during Mrs Field's recreation leave away from work.
A further significant factor is that the medical experts retained by the Applicant appear to consider that the majority of Mrs Field's duties involved her bending, lifting heavy goods, twisting or turning. From Mrs Field's evidence at Hearing and the Tribunal's reading of the duty statement and inherent requirements of the position, such activity was limited and in at least the year before the prolapse in October 1999, Mrs Field had the aid of at least one assistant. Mrs Field's other duties included supervision, stocktaking, counter duties and ordering of goods. Mrs Field also noted that she never had to take a break from work because of pain and did not load or unload boxes of packages which she could not lift. The Tribunal noted Mrs Field's evidence concerning her knowledge or absence of knowledge of weight/load restrictions of 16 kilograms. On all of the evidence, the Tribunal is not satisfied that Mrs Field was unaware of these organisational restrictions.
Further, the Tribunal notes that in Dr Yap's clinical notes, while there is mention of back pain/symptoms going back to 1994, there is no association recorded between those symptoms and Mrs Field's work. While Mrs Field was no doubt a conscientious worker and as a supervisor, wanted to set a good example and not "whinge", she still did not consider it necessary to inform her supervisor of any back condition or complaint that her work was causing her physical distress. It was only when Mrs Field provided a medical certificate to Ms Peacey from Dr Gardner in October 1999 that Mrs Field's back condition was made public.
Given Mrs Field's evidence to the Tribunal, including the inconsistent details of the onset of back symptoms, and the Tribunal's understanding of the duties of her position, the Tribunal does not consider that Mrs Field's doctors, whose reports reflect those varied histories and differing understanding of her duties, can be considered to be persuasive. Those medical opinions are based on incomplete or inaccurate information. In such circumstances the weight of such reports is diminished. It is not a matter, as Mr Slowgrove submitted, of there being a few different dates. It also goes to Mrs Field's duties at work and the circumstances during which the prolapse occurred. These details are crucial to any Tribunal or medical expert coming to an understanding of the causation in this matter based on the balance of probabilities.
The Tribunal notes the Full Federal Court decision in Health Insurance Commission v Van Reesch and Anor (1996) 45 ALD 302 which applied the High Court Decision in Zickar v MGH Plastic Industries Pty Limited (1996) 187 CLR 310 in which the High Court had held that a sudden rupture of blood vessels is an "injury". The Full Federal Court in Health Insurance Commission v Van Reesch and Anor (supra) noted that a disc prolapse, which was not an inevitable consequence of a pre-existing back condition could also be properly identified as an "injury". The Tribunal finds that Mrs Field had an injury as defined. The causation of the injury is at issue.
Under the legislation, there is a requirement that for compensation, there must be a contribution in a material degree by the employee's employment. The Tribunal notes ReWelsford and Commonwealth Banking Corporation (1984) 1 AAR 42, in which Davies J commented that it is sufficient that the employment contributed to the contraction, aggravation, acceleration or recurrence of the disease or indeed in this case, injury. The factor is not required to be the "real" proximate or effective cause of, in that case, the disease or its development. Further, the Tribunal notes that in Treloar v Australian Telecommunications Commission (1990) 26 FCR 316, the Full Federal Court discussed the use of the word "material" in conjunction with the words "contributing factor" only to emphasise that the section is not brought into play unless it is established by evidence that the features of employment did in fact and in truth contribute to the condition complained of. The causal connection must be established on the probabilities and not left in the area of "possibility or conjecture". Once there is a link established, it matters not whether the condition was large or small.
The Tribunal must look to what Mrs Field did in her employment and make a determination on the balance of probabilities as to whether or not during the course of her employment, the characteristic of the work performed or the conditions in which it was performed, contributed to or caused the disc prolapse.
In all of the circumstances, the Tribunal is not satisfied on the balance of probabilities that the nature and conditions of Mrs Field's work contributed to or caused her disc prolapse and sciatica. In reaching this decision, the Tribunal has taken into account the totality of the evidence, both documentary and oral. While the Applicant's doctors assert that Mrs Field's work contributed to her disc prolapse, they were unaware that the prolapse occurred away from work and were not fully aware of the true characteristics of her work and the inconsistent or incomplete information concerning the onset of symptoms. Medical opinions, which have as their foundation either inaccurate or incomplete information, are diminished and through no fault of their own, the experts are unable to provide a fully informed opinion.
Dr Maxwell opined that 50 per cent of prolapses occur spontaneously without any history of trauma and 50 per cent occur after a specific twisting or lifting injury. Based on Dr Maxwell's opinion and the Tribunal's understanding of all the evidence, the Tribunal finds that there was no specific incident which precipitated Mrs Field's low back pain, nor can the Tribunal be satisfied on the balance of probabilities that Mrs Field's type of work contributed to or caused her disc prolapse and sciatica. In these circumstances, it is more likely than not that the disc prolapse occurred spontaneously while Mrs Field was on leave. It may have been that the disc may have been degenerate causing some chronic low back pain. The absence on CT investigation of any degeneration is not fatal to this conclusion. Dr Maxwell noted that in Mrs Field's age group, the evidence of a degenerative disc is not always present on radiological examination. On the balance of probabilities, the Tribunal considers that the disc prolapse is due to the natural progression of an underlying condition and the Tribunal is not satisfied on the balance of probabilities that employment was a contributing or aggravating factor.

Accordingly, in all of the circumstances and for the reasons expressed above, the Tribunal determines that Mrs Field's nature and conditions of employment did not contribute in a material way to her disc prolapse and sciatica or to the aggravation of that condition. Therefore, the decisions under review are affirmed.
I certify that the 94 preceding paragraphs are a true copy of the reasons for the decision herein of Ms S M Bullock, Senior Member and Dr Lynch, Member
Signed: .....................................................................................
Stella Vaughan, Associate

Dates of Hearing  8 and 13 August 2001
Date of Decision  21 December 2001
Counsel for the Applicant  Mr B Slowgrove
Solicitor for the Applicant  Ms Togiao Kha, Bryden's Law Office
Counsel for the Respondent  Ms R Henderson

Solicitor for the Respondent Ms Olga Liavas, Australian Government Solicitor