LEE KA MAN v. HONG KONG AIRCRAFT ENGINEERING CO LTD

HCPI 355/2006

IN THE HIGH COURT OF THE

HONG KONG SPECIAL ADMINISTRATIVE REGION

COURT OF FIRST INSTANCE

PERSONAL INJURIES ACTION NO. 355 OF 2006

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J U D G M E N T

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1.  In this action, the Plaintiff sues the Defendant for damages in respect of personal injuries which she says she sustained in an accident in the course of her employment by the Defendant on 19 June 2003.  Both liability and quantum are disputed by the Defendant.

The “accident”

2.  The Plaintiff was born on 3 July 1982.  She was 20 years old on the date of the accident, and is now 26 years old.  She completed her Form 7 education in 2001.  She began to be employed by the Defendant as an aircraft engineering trainee in August 2001 and was to receive 2 years of training.

3.  During the first 3 months of her employment by the Defendant, she received training at a training centre in Junk Bay.  There she was taught concepts about work safety and risks of personal injuries in the course of her work.  She was given instructions about safety measures to which she should pay attention, as well as the proper use of equipment and tools.  The instructions also included safety regulations issued by the Government.  She said that she was given a lot of information and materials about safety at work.  In addition, she received technical training in respect of her work.  The Plaintiff said that the instructions and guidance on work safety continued after the initial 3 months of training, which were given to her by her supervisors.  The Plaintiff accepted that the Defendant placed a lot of emphasis on work safety issues and there was a culture of safe practices within the Defendant.

4.  In the course of her work, the Plaintiff often had to work inside aircraft compartments, including cargo and passenger compartments.  She said that prior to the date of the accident, she had mostly worked inside passenger compartments, but she had also worked inside cargo compartments on some 20 odd occasions.

5.  On the date of the accident, the Plaintiff had already worked for the Defendant for some 22 months.  At the material time, she was assigned to work inside the front cargo compartment of a cargo aircraft at the Hong Kong International Airport, and was working with, and under the supervision of, Mr Mak Kwok Hing (“Mr Mak”), an aircraft maintenance technician.

6.  The cargo compartment in question was, apparently, on the lowest level of the aircraft.  The floor of that cargo compartment was made of intersecting metal tracks with holes which were described by a witness (Mr Mak) as being approximately 20 inches by 20 inches in size and by another witness (Timothy Charles Cooper) as being slightly bigger than that of an “open box file”.  Underneath the metal tracks were wirings and air-conditioning and water pipes of various sorts.  The Plaintiff said that in the past when she had to work inside aircraft compartments, the floor would be covered by wooden panels or boards.  However, it is the Defendant’s case that this was so only in passenger compartments, or where the cargo compartment in which work was to be carried out was above the lowest level of the aircraft because there would be an obvious risk of fall.  Where the cargo compartment in which work was to be done was on the lowest level (as in the present case), there was no need to place wooden boards on the floor, because underneath the floor would be the base of the shell of the aircraft, which would only be about 18 inches to 2 feet below the floor level.

7.  At the material time, which was in the afternoon of 19 June 2003, Mr Mak and the Plaintiff were engaged in the task of removing 3 sets of Inertia Navigation Units (“INUs”) and INU racks located within an open cell in the Main Equipment Centre (“MEC”) of the front cargo compartment.  The INUs were removed by Mr Mak himself.  However, in order to remove the INU racks, it was necessary to first remove a drip shield which was installed to protect the INUs.  The drip shield was apparently made of a thin fibre sheet and was attached to some metal structure inside the cell by nuts and bolts.

8.  There were, amongst others, 3 sets of nuts and bolts near the floor level of the cargo compartment which had to be removed first before the drip shield could be removed.  The work procedure involved the Plaintiff using a wrench, of about 4 to 5 inches long, to hold the nuts while Mr Mak would use another tool described as a “speed driver” to loosen the bolts.  It is common ground that the nuts were hidden from sight and it was necessary for the Plaintiff to place her hand behind the drip shield and feel her way around in order to locate the nuts.

9.  According to the Plaintiff, she was asked by Mr Mak to first remove some electrical connectors which were connected to the INU racks.  However, before she had completed the task of removing all the electrical connectors, she was asked by Mr Mak to assist him to remove the nuts and bolts which held the drip shield to its proper position.  For that purpose, both Mr Mak and the Plaintiff worked in front of the cell, with Mr Mak on the left side and the Plaintiff on the right side facing each other.  The Plaintiff said that she and Mr Mak first removed the pair of nut and bolt on the left side, then the middle pair and lastly the pair on the right side.  In view of the space constraint and the fact there were two holes on the floor, one in front of her (between Mr Mak and her) and the other on her left, she had only a small area on which she could position herself and she had to adopt a squatting position, whereas Mr Mak was kneeling on his left knee and with his right leg extended into a hole on the floor, presumably resting against the base of the aircraft shell or other objects in order to maintain balance.  Also, in order to remove the pair of the nut and bolt on the left side, which was furthest away from the Plaintiff, she said that she had to lean forward, and bend and twist her back to reach the nut.

10.  According to the Plaintiff, she had to adopt an “awkward” posture during the time that she and Mr Mak were removing the said pair of nut and bolt.  The Plaintiff said that she used her right hand to hold the wrench, while her left hand was resting against the shoulder of Mr Mak in order to maintain balance.  She also said that she had to apply force to hold the nut in position to enable Mr Mak to unscrew the bolt.  According to the Plaintiff, the force that she had to apply was of the same magnitude of force that Mr Mak had to apply.  Apparently, it was relatively easier for her to remove the other two sets of nuts and bolts because she did not have to bend or twist her body so much.

11.  The Plaintiff said that the total time that it took her and Mr Mak to remove the pair of the nut and bolt on the left side was around 10 minutes, including about 2 minutes to feel around with her hand to locate the nut.  That it took so much time to remove that pair of nut and bolt was explained party by the fact that the nut in question had become deformed such that it would not fit tightly against the wrench head and so there were frequent slippings.  After the Plaintiff and Mr Mak had succeeded in removing the first pair of nut and bolt, she said that she felt something wrong and straightened up her body, at which point she heard two “pop” sounds and felt pain in her back.  She also said that she experienced an “electrifying” shock radiating down her legs at that moment.  The Plaintiff’s case is that she injured herself at that point of time.  Upon seeing that the Plaintiff was in pain, Mr Mak asked her whether she felt very painful and needed a rest.  The Plaintiff asked Mr Mak whether they needed to complete the removal of the INU racks before break time (which was at around 3:30 p.m.) and Mr Mak replied saying that his superior Mr Ng wanted the job done before break time.

12.  Hence, the Plaintiff continued with the rest of the work.  The Plaintiff and Mr Mak proceeded to remove the second pair of nut and bolt, which she said took them 1 to 2 minutes to do.  During that process, the Plaintiff still had to lean forward, but at a less inclined angle.  After that, they proceeded to remove the third pair of nut and bolt, which she said took them about 2 to 3 minutes to do.  She also said that she did not have to bend her body when removing the third pair of nut and bolt, although she still adopted a squatting position.  After that, she then resumed her previous task of removing the electrical connectors, and later still she removed 2 other sets of nuts and bolts.  Apparently, she still felt pain in her back after completion of the work and she went to see the company’s doctor on 19 June 2005.  I shall describe in greater detail the medical treatment that she received later in this Judgment.

13.  The above represents the version of events given by the Plaintiff in her evidence.  Mr Mak in his evidence gave a different account of the incident.  Mr Mak was at the time of the accident an aircraft maintenance technician.  He said that as at 19 June 2003, the aircraft in question was at an early stage of the maintenance work to be carried out which was supposed to last some 30 to 40 days.  There were other dismantling works going on in the cargo compartment in which he and the Plaintiff were working.  The work which had to be done by them was the removal of 3 sets of INUs and INU racks.

14.  According to Mr Mak, two workers working together were needed to remove the nuts and bolts.  He said that on the day of the accident, before work began he gave instructions to the Plaintiff about what she should be doing, indicating to her the positions of the 3 pairs of nuts and bolts which were to be removed.  He said that after he had given instructions to the Plaintiff as to what she should do, he occupied a central, sitting, position straddling the metal track on the floor and facing the front of the cell which housed the INU racks.  The drip shield was unfurled outwards and substantially covered his body.  The Plaintiff was initially on his right side, adopting a squatting posture.  The task that she was to perform was to use a wrench to hold the nuts in position so as to enable him to use a speed driver to loosen and remove the bolts from the nuts.

15.  Mr Mak said that they first removed the pair of the nut and bolt on his right side, than the middle pair and lastly the pair on his left side; in other words in the reverse sequence as described by the Plaintiff in her evidence.  Mr Mak accepted that the Plaintiff had to bend her back forward in order to carry out her work, but he also said that as a matter of work procedure, after the first two pairs of the nuts and bolts had been removed, the Plaintiff should move to occupy a position to his left in order to remove the last pair of bolt and nut on the left side.  By moving to the left side, the Plaintiff would also be able to adopt a more comfortable position (with less bending and twisting of her back) when removing that pair of the nut and bolt on the left side.

16.  This having been said, Mr Mak accepted, in cross-examination, that since he was effectively covered by the drip shield while carrying out his work, he did not see whether the Plaintiff had actually moved to his left side when they were removing the last pair of the nut and bolt on the left side.

17.  Mr Mak said that approximately 10 minutes after he had started to remove the first pair of nut and bolt on his right side, he found that the Plaintiff was not applying force to hold the nut and became aware that the Plaintiff appeared to be in pain in the area around her waist.  He immediately asked the Plaintiff whether she was okay and whether she need to take a rest and see a doctor.  After taking a rest for about 30 minutes, the Plaintiff continued to assist him to remove the two remaining pairs of nuts and bolts.

18.  Mr Mak also said that during the 10 minutes or so when they were engaged in removing the first pair of nut and bolt, the time that the Plaintiff actually had to apply force would be about 1 minute while he was applying force to turn the bolt.  The rest of the time was taken up by the Plaintiff trying to locate the position of the nut, and placing the wrench head around the nut.

19.  According to the Defendant’s witness Timothy Charles Cooper (“Mr Cooper”), who is the Quality Manager of the Defendant with considerable experience of aviation practices in Hong Kong and elsewhere, the nuts and bolts holding the drip shield to its proper position would not be tightly turned when it was installed, and the force that had to be applied to unscrew the bolts from the nuts would be about 15 to 20 pound inches, which would be no more than the force required to turn an ordinary door handle.  This evidence was not challenged by the Plaintiff’s counsel.

The course of treatment

20.  There is no substantial dispute about the medical treatment that the Plaintiff received after the accident on 19 June 2003.  What is in dispute is whether the Plaintiff suffered any injury in the course of her work on 19 June 2003 and if so what is the extent of the injury that she suffered.

21.  On 19 June 2003, the Plaintiff attended the Defendant’s clinic and complained of low back pain.  Physical examination revealed tensed back muscles and limited spinal movement.  The doctor gave her some analgesics.  Thereafter, she attended the Defendant’s clinic regularly for follow-up consultation and treatment for about a month, up to 21 July 2003.  The clinical notes indicated that the low back pain decreased in severity when she was seen by the company’s doctor on 23 June 2003 and 26 June 2003, and was “much reduced” on 30 June 2003 and 7 July 2003, but increased again on 14 July 2003.

22.  The Plaintiff resumed work in August 2003.  After working for about a week, her back pain increased and she attended the Accident and Emergency Department of Alice Ho Miu Ling Nethersole Hospital on 25 August 2003.  Physical examination revealed tenderness over her low back.

23.  She was referred to the Orthopaedic Clinic of Alice Ho Miu Ling Nethersole Hospital for treatment on 29 August 2003.  Physical examination revealed diffuse tenderness over her lumbar spine region with mild paraspinal muscle spasm.  The range of motion of the lumbar spine was limited.  The Plaintiff received a course of physiotherapy treatment at Alice Ho Miu Ling Nethersole Hospital in September/October 2003.

24.  The Plaintiff returned to work again on 6 October 2003.  After resuming work, she suffered from increased back pain and was admitted to Alice Ho Miu Ling Nethersole Hospital.  Physical examination revealed mild tenderness over the lower lumbosacral spine with decreased range of movement.  She was hospitalized for about 12 days between 10 and 21 November 2003 and received a course of in-patient physiotherapy treatment.

25.  The Plaintiff also received follow-up treatment at the Orthopaedic Clinic of Alice Ho Miu Ling Nethersole Hospital.  She resumed duty for a few weeks starting on 12 January 2004 but the back pain exacerbated after resuming duty.

26.  Thereafter the Plaintiff received further medical treatment, including physiotherapy treatment, from various Government hospitals and private doctors.  She also received chiropractic treatment in 2006.  She was hospitalised on 4 occasions in 2004, each lasting for a couple of days to over 2 weeks.  In her first witness statement dated 12 October 2006, the Plaintiff said that she was still attending the Department of Orthopaedics & Traumatology of Prince of Wales Hospital once every 3 months and receiving chiropractic treatment.

27.  Between June 2003 to July 2006, the Plaintiff was granted various periods of sick leaves, details of which are set out in paragraph 14 of the Plaintiff’s first witness statement.

The subsequent work history

28.  The Plaintiff resumed work in August 2003.  Thereafter, she worked intermittently in view of the various periods of sick leaves that she was granted.  She was assigned to do light duties work.  However, when there was insufficient manpower, she would be required to work in cargo compartments, which would require her to bend her back, lift heavy objects and climbed up and down.

29.  In August 2004, she was transferred from the Base Maintenance Avionics Department to the Technical Services Department of the Defendant and assigned to a clerical post, which continued for about half a year.  In December 2004, the Plaintiff was informed that she had completed the 2-Year Aircraft Engineering Trainee Scheme and her new title was that of Tradesman Grade 1.  In February 2005, she returned to the Base Maintenance Avionics Department and resumed her former duties as an aircraft mechanic, but found that she could hardly manage them physically.  Starting from 1 February 2006, upon the Plaintiff’s application, she was transferred to the Technical Support (LM) Department of the Defendant and started as a Technical Assistant (LM) Grade 1.  Apparently, the work duties of a Technical Assistant (LM) would be less strenuous as compared to those of a Tradesman in the Base Maintenance Avionics Department.  The Plaintiff is currently still working in the Technical Support (LM) Department of the Defendant as Technical Assistant (LM).

The MRI Reports

30.  There are in evidence three MRI Reports on the Plaintiff’s lumbar spine.

31.  The first one was prepared by Opus Magnetic Imaging Centre and dated 19 February 2004.  The following was stated:-

(1)  mild lumbar spondylosis with degeneration of the intervertebral discs of L3 to S1;

(2)  minimal central posterior disc protrusion at L3/4 with minimal compression of the anterior aspect of the thecal sac;

(3)  small left posterior disc protrusion at L4/5 with mild compression of the anterior aspect of the thecal sac;

(4)  moderate size central posterior disc protrusion at L5/S1 with slight caudal extension resulting in moderate compression of the anterior aspect of the thecal sac, which was most likely to be “the origin of the S1 never roots bilaterally”, which I understand to mean compression of the bilateral S1 nerve roots.

32.  The second MRI report was prepared by Apex MRI Centre Limited and dated 3 May 2006.  In that report, it was stated that there was mild to moderate left posterior herniation of the L2/3 and L4/5 discs causing slight posterior displacement of the left L3 nerve root and minimal posterior displacement of the left L5 nerve root.  However, there does not appear to be any significant compression of the left L3 and L5 nerve roots.  It was also noted that there was slight posterior herniation of the L3/4 and L5/S1 discs, degeneration and narrowing of the lower lumbar discs, and slight lower lumbar spondylosis was detected.

33.  When compared to the first MRI report, the most notable finding is that there did not appear to be any significant compression of the left L3 and L5 nerve roots, the presence of which would provide some explanation for the lower limb symptoms complained of by the Plaintiff, which will be further described below.

34.  The last MRI Report was also prepared by Apex MRI Centre Limited and dated 1 December 2008.  The following was revealed: spondylosis with small marginal spurs scattered in the mid and lower lumbar vertebral bodies, mild posterior prolapse of the degenerated mid and lower lumbar discs and slight narrowing of the L3/4, L4/5 and L5/S1 discs.  This report also confirmed that there was no impingement on the thecal sac or S1 nerve roots.

The evidence of the medical experts

(i) Dr Lam’s 1^st Report

35.  At the trial, the Plaintiff called Dr Johnson Lam to give evidence and the Defendant called Dr David Cheng to give evidence.  Each expert has prepared 2 medical reports.  Dr Lam’s reports are dated 12 June 2005 and 15 April 2007 respectively, and Dr Cheng’s reports are dated 17 October 2005 and 19 September 2007 respectively.

36.  Dr Johnson Lam first saw the Plaintiff in his clinic on 9 June 2005.  In respect of the circumstances of the accident, Dr Lam was told by the Plaintiff that at the time of the accident, she had squatted with the back bent forward for about ½ hour to disassemble equipment and felt tired, and when she rose from a squatted position, suddenly she heard a “pop” sound in her back, and experienced severe back pain.  She stopped for a while and then continued to work.

37.  The Plaintiff also told Dr Lam that her pre-accident job required occasional lifting of heavy objects, frequent bending of her back, climbing ladder, and long hours of standing and walking.

38.  In his first report, Dr Lam stated that according to the MRI report prepared by Opus Magnetic Imaging Centre, it was revealed that there were multiple levels of disc protrusions, the worst being over the L5/S1 level with probable compression of the bilateral S1 nerve roots.

39.  In the “Past Medical History” section, it was stated that the Plaintiff did not have pain in or injury to the back prior to, or any injury after, the subject accident.

40.  In the “Complaints” section, it was stated that the Plaintiff still complained of pain over the lower lumbar region, and the pain increased with prolonged sitting for 45 minutes, and walking or standing for 1 hour.  The Plaintiff also complained that the pain radiated from her back to the upper back since 2 to 3 months ago (i.e. starting in about March or April 2005), and the pain radiated from the back to both lower limbs.  It was also said that activities of daily living including hygiene and self care were largely unaffected.

41.  On physical examination, Dr Lam found that there was muscle guarding over the lumbar region, and muscle spasm and tightness over the right paraspinal muscles of the lumbar spine.  In prone lying, there was still guarding over the lumbar region at the right paraspinal muscles but the tightness of the muscles decreased.  There was tenderness in the lower lumbar spine at the L3/S1 levels in the midline, and mild tenderness over the paraspinal muscles.  There were also decreased ranges of flexion and extension but not lateral bending of the back, as well as some limitation of movement of the right lower limbs.

42.  Radiographs showed some decrease of the lumbar lordosis, and minimal degenerative changes in the lumbar spine.

43.  According to Dr Lam, the encroachment/compression of the S1 nerve roots could explain the Plaintiff’s complaint of pain radiating down both of her lower limbs.

44.  Dr Lam considered that the Plaintiff’s back condition had reached maximum medical improvement.  In view of the Plaintiff’s impairment and the requirements of her pre-accident job, Dr Lam considered that she should not be able to return to her pre-accident post in servicing airplanes.  He recommended her to consider changing to a job that required only light to medium physical demands which would allow her to alternate between sitting and standing/walking during work, e.g. as a clerical worker or an executive officer.

(ii) Dr Cheng’s 1^st Report

45.  Dr Cheng first saw the Plaintiff in his clinic on 19 August 2005, some 2 months after she was seen by Dr Lam.  She told Dr Cheng that, at the time of the accident, she had been working in a bent position for over 30 minutes.  After finishing the job and on getting up, she felt pain over the back.  She said that there was no contusion, fall, lifting or twisting.  She rested for a short while and continued with her work.  She then attended the company’s clinic and afterwards did 3 more hours of overtime work.

46.  In respect of her current complaints, the Plaintiff told Dr Cheng that she had pain over her back and both buttocks. She described the pain as bearable, about grade 2 or 3 on a scale of one to ten.  She said that the pain increased on bending, turning and twisting of the back, and that the pain was worse during her periods, and sometimes radiating to both lower limbs.

47.  On physical examination, Dr Cheng noted that there was local tenderness over the L4/5 region and the left paraspinal area.  There was also some tightness on straight leg-raising.  Otherwise, her range of motion was good.  Radiological examination revealed slightly reduced lumbar lordosis.

48.  Dr Cheng noted that when the Plaintiff was first seen by the company’s doctor (Dr Ng Man Yiu) on 19 June 2003 (mistakenly stated to be on 19.9.2003 on page 7 of Dr Cheng’s first report), the complaint was dysuria (pain on micturition) and low back pain, but there was no mention of any injury at work.  Dr Ng’s diagnosis was that of urinary tract infection (which could cause some back pain).  Coupled with the fact that the Plaintiff mentioned that there was no fall, contusion, or twisting of the back, Dr Cheng considered that there was reason to say that the Plaintiff did not suffer any particular injury to any particular part of the body at any specific point in time on 19 June 2003.

49.  Dr Cheng also observed that although the Plaintiff had undergone a protracted course of treatment and had been reviewed by private and public orthopaedic surgeons as well as by her general practitioner, nothing remarkable was noted except some muscle spasm.  There was no bony injury or neurological complications.  The MRI scan showed that there was some disc bulging with hardly any nerve root complication, which was quite commonplace.  There was no disc prolapse or any other pathology.  I pause to note that the term “prolapse” was not used in the first or second MRI reports, but appeared in the third MRI report, which was not in existence at the time that Dr Cheng prepared his first report.  I should also mention that Dr Lam accepted in cross-examination that the terms “bulging”, “protrusion” and “herniation” of the discs were often used interchangeably, although he also said that there was a distinction between diffuse bulging and focal bulging.

50.  Taking into account the whole clinical picture, Dr Cheng opined that the Plaintiff probably had a weak back generally and there was no pathology in her back.  He considered that the prognosis should be good, and that with back exercise and taking a sensible approach to work, the recurrence of symptoms should diminish.  Dr Cheng emphasised that the Plaintiff’s physical impairments were assessments on her back as it was, and that there was nothing medically to suggest that they were caused by what happened on 19 June 2005.  Dr Cheng also considered that the Plaintiff was capable to resume her job as a mechanic, but she should do exercise to keep a good back and take a sensible approach to work.

(iii) Dr Lam’s 2^nd Report

51.  Dr Lam’s second report was essentially prepared in reply to Dr Cheng’s first report.  Dr Lam expressed the view that, having regard to the young age of the Plaintiff, the fact that she did not have any pre-existing back pain or back injury, and the fact that she developed persistent back pain afterwards, it was probable that the injury that she sustained on 19 June 2003 caused the multiple levels of disc protrusions.  Dr Lam considered that the most probable cause of the Plaintiff’s injuries was the following: when the Plaintiff was using force to unscrew/untwist a tight nut, there was some increase in the strain on the back with some twisting, and since the Plaintiff had to unscrew 2 tight nuts (taking 15-30 minutes to do so, which suggested that the nuts must have been very tight), it was probable that the multiple disc injuries were caused by excessive force on the back, which was in a vulnerable position as a result of the squatting and bending posture adopted by the Plaintiff.

52.  In respect of Dr Cheng’s observations on the findings of the MRI scan, Dr Lam expressed the view that the multiple disc protrusions from L3 to S1, showing signs of degenerative changes in the discs, would be very uncommon for a young woman like the Plaintiff.  Taking into account the fact that the Plaintiff was asymptomatic before the accident and that she did not have previous back injury, such changes were most likely caused by the subject accident.

53.  Lastly, Dr Lam disagreed with Dr Cheng about the prognosis.  He also considered that the Plaintiff should avoid duties that caused heavy physical demand on the back, and she should not be able to return to her former job or indeed continue with her present job.  Dr Lam recommended that the Plaintiff should consider changing to a job that required only light to medium physical demands and one that allowed her to alternate between sitting and standing/walking, such as a clerical worker or an executive officer.

(iv) Dr Cheng’s 2^nd Report

54.  The Plaintiff attended Dr Cheng’s clinic on a second visit on 11 June 2007, and this led to his second report dated 19 September 2007.  On this occasion, the Plaintiff complained of a stiff sensation and aches over the low back constantly.  However, the symptoms were quite bearable, and she could carry out her daily activities without difficulty.  The Plaintiff also said that there were sudden episodes of some back pain without any cause, sometimes after simply getting up from sitting position or during changes of weather.

55.  There was nothing remarkable on physical examination, except some mild tenderness over the L4/5 region of the low back, in the mid-line and over the left side.  Radiological examination showed, as before, a slightly reduced lumbar lordosis.

56.  Dr Cheng commented there was no objective findings to suggest any significant pathology of the Plaintiff’s back.  There was no neurological deficit, and no bony injuries.  In so far as the first and second MRI scans were concerned, Dr Cheng’s interpretation was that both showed mild disc bulging of the lumbar disc at multiple levels, at L2/3, L3/4 and L4/5, but no nerve root compression and no canal narrowing.

57.  Dr Cheng expressed the view that disc bulgings were features of disc degeneration, being shown up by the powerful MRI scanning method.  They were present in the majority of individuals of the Plaintiff’s age group.  Degeneration was a natural occurring process, and was not caused by what happened to the Plaintiff on 19 June 2003.  Dr Cheng considered that a single event as that described by the Plaintiff simply could not have caused the bulgings – they developed insidiously over a period of time.  Dr Cheng referred to the work of Firoozinia et al, “MRI and CT of the Musculoskeletal System” at p.62, which stated as follows, “Bulging of a disc is due to desiccation and degeneration.  It develops over many years, essentially because of the normal wear and tear of aging.  Acute traumatic injuries such as falls or motor vehicles accidents do not cause bulging”.

58.  Dr Cheng said that, on the basis of the Plaintiff’s description of the events on 19 June 2003, there was no fall, no contusion, no twisting, and no actual physical injuries.  According to her, she was screwing or unscrewing some nuts and bolts in a squatted position, with the back bent.  There was no lifting of heavy objects.  This could not cause stress, or heavy stress, on the back.  Dr Cheng considered that it was possible that there might be some fatigue, or some aches and pain, but certainly not sufficient to cause bulging of multiple lumbar discs and persistent aches and pain for three or four years afterwards.  At the highest, what happened on 19 June 2003 could be regarded as an act of daily occurrence contributing to wear and tear.  Dr Cheng concluded that what happened on 19 June 2003 did not cause any damage to the back, or aggravate the status of her back.

(v) The oral evidence of the experts

59.  In his evidence in chief, Dr Lam said disc protrusion could be asymptomatic for an adult.  However, in severe cases, it could cause irritation or compression of the nerve which could lead to numbness of parts of the body.  Dr Lam also said that merely by squatting and bending for 8 to 10 minutes should not cause any injury to a person’s back, but if that person also had to twist the back and carried out strenuous work at the same time, the stress on the back could cause disc protrusion.  In cross-examination, Dr Lam said that he was told by the Plaintiff that she felt tired after working (dissembling something) for about 30 minutes with her back bending forward, and his impression was that the Plaintiff was engaged in a strenuous task, and his opinion on the cause of her back injury was based on the assumption that she had to bend forward continuously for 30 minutes while doing a strenuous job.  He did not expect, however, that she would be applying force continuously for 30 minutes, and he did not ask the Plaintiff what force she had to apply to do her job.  Dr Lam also agreed that the spinal column was a strong part of the body which was resilient to stress.  It was protected by muscles which would normally be flexible and strong.  If there was no fatigue, the muscles protecting the spine should be able to resist rather strong force.

60.  When asked about the Plaintiff’s complaint of numbness on both legs and the buttocks, Dr Lam accepted that there was no pathology which could explain that complaint.

61.  In cross-examination, it was put to Dr Lam that his whole expert report demonstrated an intention to formulate a report to assist the Plaintiff’s claim.  Although, for reasons which I will come to later, I am unable to accept Dr Lam’s conclusion as regards the cause of the Plaintiff’s back injuries, I wish to make it clear that I do not accept this criticism of Dr Lam.  I consider that Dr Lam was doing his best to assist the court in a fair, objective and professional manner, and his evidence was based on information made available to him, including information provided by the Plaintiff herself, which turned out not to be entirely accurate. 

62.  Dr Cheng said in his evidence in chief that about 20% to 30% of young women at the age of 21 would have lumbar spondylosis (or degeneration).  He did not agree with Dr Lam that sprained injury would cause protrusion (or bulging) of the lumbar discs, and considered that a trauma involving a very high magnitude of axial compression would be required to produce protrusion of the discs.  On the basis of what was described by the Plaintiff, namely, squatting down, bending forward with some twisting of the body, and exerting some force using a hand held tool, Dr Cheng expressed the view that, from a medical point of view, it was very unlikely (unusual) that multiple levels of disc protrusions would be caused.  Dr Cheng also said that if what happened on 19 June 2003 did cause multiple levels of disc protrusions, it would have been a very serious condition, and there would not be a fast improvement of her condition as could be seen form the clinical notes of the company’s doctor between 19 June 2003 and 21 July 2003.  Dr Cheng maintained his evidence in cross-examination.

Findings of fact in relation to the circumstances of the accident

63.  In respect of the two versions of the events of the accident given by the Plaintiff and Mr Mak, I prefer the evidence of Mr Mak, for the following reasons:-

(1)  The Plaintiff’s version is inherently improbable.  Having regard to the work to be done by Mr Mak, it was natural for him to occupy a central position facing the front of the cell which housed the INU racks.  This position would facilitate him using the speed driver to unscrew the bolts and remove them from the nuts, whereas if he had positioned himself on the left side of the cell facing the Plaintiff, he would have to extend and twist his right arm in an awkward manner to unscrew the bolts using the speed driver.  Also inherently improbable in the Plaintiff’s version is the suggestion that the first pair of the nut and bolt that she and Mr Mak removed was the pair on the left hand side.  It is not disputed that the Plaintiff was initially on the right hand side of Mr Mak, with the drip shield unfurled outwards substantially covering the body of Mr Mak.  In that position, the drip shield would have blocked or at least hinder the Plaintiff’s access to the nut on the left hand side, whereas the Plaintiff had an obviously easier access to the nut on the right hand side.  It seems to me both natural and probable that the Plaintiff and Mr Mak would first remove the pair of the nut and bolt on the right side, then the middle pair, and lastly the pair on the left side.

(2)  The Plaintiff’s oral evidence is materially inconsistent with her witness statements.  In the Plaintiff’s first statement, she said that she and Mr Mak spent around 15-20 minutes to loosen 2 screws, then she felt that her back was a little tired and she stood up, and it was at that time that she felt stiffness and pain on her back.  In her supplemental statement, the Plaintiff claimed that she was “removing the second screw, i.e. the screw in the middle of the underneath of the waterproof cap, when my waist began to hurt”.  However, the Plaintiff said in her oral evidence that after she and Mr Mak had succeeded in removing the first pair of nut and bolt and before they commenced to remove the second pair of nut and bolt, she stood up, and heard two “pop” sounds and felt pain in the back.

(3)  There are other inconsistencies in the Plaintiff’s evidence.

(a)  It appears from Dr Lam’s 1^st report that she told Dr Lam that her work required occasional lifting of heavy objects and frequent bending of the back.  However, in cross- examination, the Plaintiff said that during the 22 months that she was in the employment of the Defendant prior to the date of the accident, she seldom had to bend her back or lift heavy objects (she regarded a weight of about 15 lbs to be a heavy object).

(b)  The Plaintiff apparently told both Dr Lam and Dr Cheng that she had to bend forward for some 30 minutes before she stood up and felt pain in the back.  It also appears from Dr Lam’s second report that the impression that she had given Dr Lam was that for a continuous period of some 15-30 minutes, she had to apply force to unscrew 2 tight nuts when occupying a squatting and bending posture.  Even on the Plaintiff’s evidence, what she said to the doctors cannot be correct.

(c)  The Plaintiff never claimed in her two statements that after she had stood up, she heard two “pop” sounds and felt an electrifying pain radiating down to the legs.  It also appears from a Physiotherapy Assessment Form that the Plaintiff told the physiotherapist on 1 September 2003: “no sound heard”.

64.  In the final submissions of the Plaintiff’s counsel, there was no suggestion that Mr Mak’s evidence was inconsistent or inherently improbable or should for any other reasons be rejected.

65.  In all, I accept the evidence of Mr Mak in relation to the circumstances of the accident.  To the extent that the Plaintiff’s evidence is inconsistent with that given by Mr Mak, I reject her evidence.

Finding of fact in relation the cause of the Plaintiff’s back injuries

66.  The question is whether what happened on 19 June 2003 to the Plaintiff could have produced the severe back injuries now suffered by the Plaintiff.

67.  Dr Lam’s conclusion that the Plaintiff’s back conditions, namely, multiple disc protrusions from L3 to S1, were the result of the work activities carried out by the Plaintiff on 19 June 2003 was based on 3 factors: (i) the Plaintiff’s young age, which made it unlikely that she would have a degenerated spine with multiple levels of disc protrusions, (ii) there was a definite episode occurring on the day in question during which the Plaintiff had to squat and bend/twist the back and use force to unscrew a tight nut with a tool, and (iii) the Plaintiff was asymptomatic before the episode and there was a sudden onset of low back pain after that.

68.  I accept that points (i) and (iii) would give some support for Dr Lam’s conclusion.  However, the critical issue is (ii), i.e. whether what happened on 19 June 2003 as found in this judgment could have caused the serious injuries to the Plaintiff’s back.  Dr Lam’s view is to a large extent dependent on what he was told by the Plaintiff as to what happened on that day, in particular, that she had to adopt a bending posture for about 30 minutes while carrying out her work and she was during that period of time engaging in a strenuous exercise.  However, it is clear on the evidence that she did not bend her back for 30 minutes.  According to the Plaintiff, she suffered injuries in the course of removing the first pair of nut and bolt on the left side, or immediately afterwards.  It is the evidence of both the Plaintiff and that of Mr Mak that it took them approximately 10 minutes to remove that pair of nut and bolt.  During that period of time, the Plaintiff did not have to apply force all the time.  The evidence of Mr Mak, which I accept, is that she had to apply force for about 1 minute only.  Further, the evidence of Mr Cooper, which was not challenged, is that the force that had to be applied would be no more than that required to turn an ordinary door handle.  In any event, I find that the first pair of the nut and bolt which the Plaintiff and Mr Mak removed was the pair on the right side.  It is clear on the evidence that, for the purpose of removing the pair of nut and bolt on the right side, the Plaintiff did not have to bend her back much in order to carry out her work.  In all, I consider that Dr Lam’s point (ii) has little force having regard to the evidence which I have accepted in this case.

69.  I also accept Dr Cheng’s evidence that it is very unlikely that something as described by the Plaintiff could produce injuries as severe as multiple disc protrusions, and his evidence that some force, impact or compression of considerable magnitude far greater than that experienced by the Plaintiff on 19 June 2003 would be required.

70.  I accept that the Plaintiff could have suffered some minor sprained injury to the muscles on the back on 19 June 2003 which, in an ordinary case, should recover within a short period of time.  What she is complaining of, however, is something of an entirely different order.

71.  Approaching the issue of causation as a matter of common sense and judging it on the balance of probabilities (see Lee Kin Kai v Ocean Tramping Ltd [1991] 2 HKLR 232 at 235-236, per Hunter JA), I am not satisfied that the Plaintiff’s back injuries were caused by the work activities that she carried out on 19 June 2003.

72.  Having reached this conclusion, it would be speculative for me to offer any view as to what was or were the cause or causes of the Plaintiff’s current back conditions, and I shall refrain from doing so.

No breach of duty

73.  In the Statement of Claim, the Plaintiff’s claim against the Defendant is based on negligence, breach of contract of employment and breach of statutory duties.  It is clear from the Plaintiff’s final submissions that all these different causes of action are ultimately based on a complaint that there was a failure on the part of the Defendant to instruct the Plaintiff to adopt a “proper posture” when carrying out the work.  It is said in the Plaintiff’s final submissions that “unlike the comfortable posture of Mak in the video – P would have been bending her upper body in a very uncomfortable squatting position while she was performing the said task … in P’s position, it would cause great pressure on her back when she had to bend her upper body to reach the far end (the nut on the left side) when she help to undo the nut”.  The submission advanced on behalf of the Plaintiff is that she should have been given the benefit of Mr Mak’s posture, namely, sitting on the metal track facing the front of the cell which housed the INU racks with her lower limbs beneath the floor level.  In this connection, the Plaintiff relied on the fact that she had been instructed that she should not place her feet into the “holes” on the floor to avoid damaging the installations below the floor.

74.  It is apparent that a central plank of the Plaintiff’s submissions is that she had to bend her upper body in a very uncomfortable position in order to carry out her work, in particular when removing the pair of nut and bolt furthest away from where she was.  However, the Plaintiff accepted in her evidence that when she was engaged in removing the pair of nut and bolt on the right side, she did not have to bend or twist her body, and when she was engaged in removing the middle pair of nut and bolt, she needed to lean or bend forward a little only.  The Plaintiff also said that there was no difficulty encountered when removing these two pairs of nuts and bolts.  In relation to the pair of nut and bolt on the left side furthest away from the Plaintiff, it was a simple matter for the Plaintiff to move to the left side of Mr Mak to carry out her job.  Irrespective of whether the Plaintiff had been given any specific instruction by Mr Mak that she could move to the left side, I consider this was a matter of common sense and she hardly needed to be given any specific instruction in this regard.  It is clear from the evidence of Mr Mak that this was what he expected the Plaintiff to have done, and he would have no objection to the Plaintiff moving to his left side if she considered that would be the most comfortable position for her to carry out her work.

75.  At the bottom of the matter, the work that the Plaintiff was tasked to carry out was, in my view, a simple operation involving no obvious risk of injury to her back.  The Defendant was quite entitled to leave it to the Plaintiff to assess the working environment and her own ability and to choose the most appropriate position or posture to carry out the work.  I do not consider that, in the circumstances of this case, it can be said that there was a reasonably foreseeable risk of injury such that the Defendant was required to give specific instructions to the Plaintiff to avert the risk.

76.  In all, I am not satisfied that the Plaintiff has proved that the Defendant was negligent or in breach of the contract of employment or any statutory duties in this matter.

Conclusion

77.  For the above reasons, I dismiss the Plaintiff’s claim against the Defendant.  Since I have come to a clear view on the issue of liability, I do not consider that it would serve any useful purpose for me to making any findings on the quantum of damages.

78.  The Defendant is entitled to have the costs of this action paid by the Plaintiff, to be taxed if not agreed.  The Plaintiff’s own costs are to be taxed in accordance with the Legal Aid Regulations.

79.  Lastly, it remains for me to thank counsel for the assistance that they have rendered to the court.