Manawatu Knitting Mills Limited v Accident Rehabilitation and Compensation Insurance Corporation

IN THE DISTRICT COURT HELD AT WELLINGTON Decision No. 139/98 UNDER The Accident Rehabilitation and Compensation Insurance Act 1992 AND IN THE MATTER of an appeal pursuant to section 91 of the Act BETWEEN MANAWATU KNITTING MILLS LIMITED of Palmerston North Appellant (Appeal No. DCA 359/96) AND ACCIDENT REHABILITATION AND COMPENSATION INSURANCE CORPORATION a body corporate duly constituted under the provisions of the said Act Respondent DECISION OF JUDGE A W MIDDLETON ON THE PAPERS This is an appeal by Manawatu Knitting Mills Limited, the employer of Ms A R Matson (the worker) who was found by the respondent and the Review Officer to have suffered a work injury being Carpal Tunnel Syndrome which she suffered in the course of her employment by the appellant. I have received submissions from Ms J Forrest, counsel for the appellant and from Ms S Scott, counsel for the respondent with the request that I issue a decision on the papers. In addition, I have received from the appellant an affidavit from Mr A A R Griffin, an Orthopaedic Surgeon and I have received from the respondent a report from Dr WED Turner, a Specialist in Occupational Medicine, both of which are accepted by the Court as additional evidence on appeal. The worker lodged a claim with the respondent on 4 September 1992 stating that she suffered "occupational overuse syndrome - carpal tunnel syndrome" in the course of her 2 employment with the appellant. Her explanation as to how the injury was caused states: "My employer replaced machinery with 4 high production machines that produce knitwear panels (quickly) & require a small part to be separated from the bottom of the panel and this action has caused a continual ache in my right wrist & this is what caused it." At the request of the respondent, the appellant completed a questionnaire on 11 November 1992 in which it stated that the worker's injury was not work related and stated that the worker had complained about the injury while at work but that she had been trying for some months to cease the employment. The worker was also requested to complete a questionnaire and on 2 December 1992 she stated that the problem had come about after the installation of the new machines which were faster than the machines she had previously used and that the pain had appeared some four weeks after the introduction of the new machines. She was not aware of any non-work activities which may have contributed to the condition. The respondent referred the file to its District Medical Advisor, Dr N Smidt who considered "the history does suggest this is work related but the discrepancy between employer and employee needs clarification". Dr Smidt's file memorandum indicated that she had spoken to the worker's Supervisor. The memorandum reports some difficulty between the worker and her employers. In the ultimate Dr Smidt considered that "information from employee suggest work is a significant figure." On 8 January 1993 the respondent advised that it had accepted her claim under section 8(2)(b) of the Act as being "personal injury caused by gradual process arising out of and in the course of her employment." Following the issue of that decision the appellant's General Practitioner, Dr A Borwick notified the respondent: "The diagnosis remains as previously indicated, occupational overuse syndrome affecting her forearms, shoulder and upper back. Her prognosis is that following perhaps 6 - 9 months rest she should be able to resume most work of a similar nature, as I would expect useful improvement in such a time frame." As the appellant had been advised that the respondent would assign the cost of the claim to its claim history the appellant lodged an application for review of the respondent's decision. At the review hearing the worker produced a report from ERGOS, an Occupational Health and Ergonomic Services dated 18 July 1996 in which it is stated: "After observing the workstation and observing an employee at this station the following comments are made 3 182 The activities are varied and each are of short duration, including those that require a higher static load like in reaching to top of machine to change the cones. 3 The workcycle is fairly long and discretionary, ie the employee trims a garment, write something down, change cones, tie garments in bundles and place onto shelves. As far as I have been able to ascertain the sequence and order of those activities is entirely discretionery (sic). 4 Reech (sic) may be a problem for small people. The machine is reachable from front and back and cones are not heavy. Depending on garment and programme cones are changed about (up to ?) 100 times a day over a 8-10 hour period. 5 The speed of work is partly dictated by the machines, ie garments observed took from 13-55 minutes to finish. Plain garments finish a lot faster, however it is up to the employee to decide how fast they are trimmed and packed. 6 In between activities at the machine, the employee also goes out "hunting" for orders. There are overall numerous occasions for micropauses and small rest breaks from tasks. 7 Changing cones about 100 times a day reaching up is not considered light, however with the numerous breaks and other tasks in between it is not to be considered heavy either. 40-45 hours a week (five days) if up to over 50 then divided into six days. It is essential that people have sufficient opportunity to rest and recover fully for the next days work. Sometimes this is not possible for people who work 10 hours a day and then have household to look after. 10 Be it either physical or mental, it is an important factor with OOS occurrence. However, some stress may be work related, other stress factors may be of a private nature. COMMENTS: I do understand from information received that the current employee handles eight machines and her predecessor handled four machines. In that case the pace would have been slower, less cones handled, less items trimmed, etc. Overall the job has a low to reasonable static or isometric muscle load, especially in relation to duration of the muscle contraction. The tasks are varied and workcycle discretionary. The hours, however, especially in the busy season seem quite long. CONCLUSION: Occupational Overuse Syndrome is rather a personal matter in the case that some people are more likely to suffer from it than others. Furthermore factors at work 4 may be however in a number of cases external factors may also play a role. In this case at the Shima machines it is my opinion, in relation to workload, work methods and workcycle that the occurrence of OOS may very well have different participating factors." The worker also gave evidence at the review hearing and was subject to examination by the appellant's representative. The Review Officer found that the ERGOS's assessment was undertaken at a time when the worker was not present so that the Assessor was not able to assess her ability at carrying out her particular task. The Review Officer noted that it was significant that the worker's problem had began four weeks after the introduction of the new machines and that there were no non-work factors which could have caused or contributed to the condition. She therefore confirmed that that the worker was entitled to cover for Carpal Tunnel Syndrome arising out of and in the course of her employment. It is against that decision which the appellant now appeals. In support of the appeal Mr Griffin has provided an affidavit in which he has explained the nature and possible causes of Carpal Tunnel Syndrome which he describes as being "a very common neurological disorder". Mr Griffin did not examine the appellant nor her workplace but gave a general description of the nature of the syndrome and then concluded his affidavit by stating: "15. I am relatively familiar with the Accident Compensation and Rehabilitation Insurance Corporation's legal test for injuries caused by gradual process. The difficulty with such a test is that it can be very difficult to determine whether a particular task or activity is causative or has contributed to Carpal Tunnel Syndrome. As I have indicated, it can sometimes be obvious, but more often than not, that is not the case. It is quite conceivable that if 100 people were doing the same activity, one of them would get Carpal Tunnel Syndrome. Whilst that particular activity might be said to have led to the development of Carpal Tunnel Syndrome, it is equally clear that that person had an underlying susceptibility to the Syndrome not shared by the other 99 people. The other contributing factors can be difficult to ascertain. 16. I am aware that the second limb of the ARCIC test requires that the activity which is deemed to be causative of Carpal Tunnel Syndrome is "not found to any material extent in the non-employment activities or environment of that person". This can be equally difficult to assess. Before those questions or issues can be determined affirmatively, it would be necessary to undertake an assessment of a person's work and non-work activities and to assess if there is anything unusual about those activities. 17. The same difficulty arises in determining whether the risk of suffering Carpal Tunnel Syndrome is significantly greater in persons performing any given employment task than the persons who do not perform that task in that environment. Again, the specific activities (work and non-work) and 5 the presence or absence of an underlying susceptibility, would need to be assessed before implicating either the task or the environment." The report from Dr Turner dated 10 September 1997 states that he has examined the worker and visited her workplace. The early part of his report notes the appellant's history and that she first commenced work with the appellant in April 1988 as a Textile Technician Trainee. She then attended the Auckland Technical Institute between June 1988 and December 1989 undertaking a Textile Technician Certificate course. During her period in Auckland she worked in a knitwear factory during her holidays, the work there being similar to that which she undertook with the appellant. When she had completed the course she returned to her employment with the appellant as a Technician Trainee. When problems arose between the worker and her then Supervisor, she moved to a different department where she worked on shift work for a period of some two years. After some difficulties with depression, partly caused by her work and partly by her relationship with her boyfriend, she considered that her work as an operator amounted to a demotion because her full skills were not being utilised. Dr Turner carried out a full neurological examination of the worker and all the normal tests necessary to consider the worker's claim. He concluded his report by stating: "Workplace Visit A workplace visit was undertaken for biomechanical task analysis for risk of OOS development at Manawatu Knitting Mills on 09/09/97 in the presence Alayne Matson and her case manager Pam Rush. The Shima Seika machines were assessed there being a total of 8 machines in the Department. It should be noted that Alayne only operated 4 Shima machines and that since she worked at Manawatu Knitting Mills production has increased approximately by 20%-30%. The assessment was carried out in the presence of Mr P Finn, Technician, and Mr R Redpath, Supervisor, and I am advised that despite the increased production there have been no further cases of work related musculoskeletal pain. I viewed the SES Product Manual for the Shima which is available for the operators to read, these manuals providing safety information. The machines themselves have inherent safety procedures such as machine cut outs which are activated with the opening of the panels. In other words operators can not place their hands into the moving parts of the machine when the machine itself is operating. I viewed the Manawatu Knitting Mills ISO Quality Manual which has been in operation for 2 years, this being a comprehensive guide to the safe operation of all the machinery. Prior to this the factory had a safety manual all the available information being formalised and compiled into the ISO Manual. Al the machines were running at the time of my visit and I was able to ascertain that the cycle time for each machine varied according to the jersey panel style ranging from 20 minutes for simple designs through to 30 minutes for cable and Fair Isle designs. The sub tasks contained within the cycle involved the following activities: 6 1. Collecting, loading of cones then threading approximately 10%-15% of the cycle. The weight of the cones averaged around 300 gm with variation of 50 gm to 1 kg. Three to six cones were carried by the operators at any one time. 2. Change overs occupying approximately 15% of the cycle varying from 11/2- 15 minutes according to the number of threads involved. Change over is usually proceeded by a blow down to rid the machine of all dust from the previous operation. Change overs involve a dynamic work activity where there is tying of threads, reaching above the shoulder, threading the threads through the feeders, then tying them off at waist level. It was noted that the reach above the shoulder was not sustained occupying a maximum of 3 seconds at any one time with the majority of the work being carried out at waist level. Alayne height is 167 cm and she had long arms which were measured at 75 cm, giving her a reasonable reach. It was noted that there was a tendency for her to bend forward with considerable flexion of the thoracic and cervical spine and forward drawing of the shoulders when tying off. Her technique was quite differing from that of the present operators who were adopting a more upright posture. 3. Trimming. This consists of some 20%-30% of the work cycle and involves the use of scissors held in the right hand there being neutral postures of the wrist in the process. Very little force was evident when cutting the threads. 4. Mending. This occupied some 15%-20% of the cycle and involved a 10 gauge latch needle. Once again there was very little force and neutral postures were evident throughout. 5. Down time. This occupied 20% of the cycle where operators had discretionary time in which to observe the operation of the machines. Operators can sit down during this time and are free to take stretching exercises for relief of fatigue. 6. Bundling and carrying panels. This occupied 5% of the cycle where bundles of 12 body panels and 24 sleeve panels weighing in the region of 5-6 kg per bundle are carried a short distance. The time spent carrying this weight is 11/2-2 minutes in a shift. Alayne worked an average 40 hour week and in the time just prior to developing musculoskeletal pain in July 1992 according to records supplied to me by Mr Redpath worked increased hours. These hours are attached to this report as an appendix. It should be noted that there was no bonus scheme in operation. The average production at the present time is 200 panels produced per shift and I am advised that the production was 20%-30% less than this when Alayne worked at the Mill. Alayne herself elected trimming as the predominant problem in terms of her pain disorder and it should be noted that this is a low force, low repetitive activity [in the context of all the other sub tasks undertaken in the work cycle]. The speed of work is dictated by the machines, currently there is 4 change overs per shift plain garments finishing a lot faster as previously noted. It is however up tot the individual employee to decide how fast garments are trimmed, mended 7 and bundled. Therefore there is considerable discretion available to operators in terms of pacing and production time management. According to Jason Stewart, the operator of the machines on duty at the time of my visit there is 15 minutes per hour of available down time when the hands are idle and the machines are essentially being observed to ensure they are operating correctly. The biomechanical task analysis in terms of risk for OOS reveals a low frequency low force operation which constitutes a very low risk from Shima machine operating as a stand alone activity. Opinion In my opinion Alayne has developed a regional pain syndrome affecting her right shoulder and upper limb with features of a chronic myofascial pain syndrome. Clinically she had moderately active trigger pints in the forearm wrist and finger extensors, pronators teres, in the scapular elevator muscles, pectorales of the chest wall and the right thoracic outlet. In addition she manifested an untoward forward drawn shoulder posture. There is a clear past history of psychosocial stress arising both from her non-occupational and occupational environment. There is little doubt that her pain syndrome has arisen in the main from the influence of stress rather than from faulty ergonomics. This is reflected in the fact that her pain at presentation did not follow the usual crescendo pattern during the working day or throughout the working week with decrescendo over the weekends. When underlying stress is the predominant cause of muscle tension the muscles remains tense throughout the week confusing the relationship to the work process. Biomechanical analysis revealed that the operation of the Shima machines was in fact low risk work. Traditionally in occupational medicine the risk of developing a gradual process syndrome [OOS] is assessed by determining: 1.] The rate of repetition of movements over time. 2.] The exhibition of force of these movements [including weight carried, degree of friction, tool handle size and shape or the size and shape of objects being manually handled]. 3.] The frequency of deviated joint postures from mid anatomical positions. 4.] Allowance for rest from fatigue within the work cycle. 5.] The stress reactivity of the individual concerned. Risk is therefore highest in those occupations characterised by rapid repetitive movements performed over prolonged periods where there are also forceful exertions involved. Risk is compounded when these movements are undertaken in constrained or untoward postures and when there is no appropriate allowance for rest from fatigue in the work cycle, eg. 3 minutes 10-15 second micropauses , 20:10 regime, 5 minute rest breaks per 30 minutes for exercising. On a descending scale one would therefore have; 8 high risk work, high repetition, high force movements, poor posture, absent rest allowances, no rotation. medium risk work, high repetition, low force movements, poor posture, absent rest allowances, no rotation. moderate risk work, moderate repetition, moderate force movements, balanced postures, adequate rest allowances, exercises undertaken, some rotation. low risk work, low repetition, low force movements, good posture, excellent rest allowances, exercises undertaken, full rotation repetitive to non-repetitive in 20:10 regime. It should be noted here that high risk work can be transformed to a lower risk category even in the face of moderate repetition and moderate force of movements when appropriate interventions are made for balanced postures, rest allowances and stretching exercises and job rotation. I would conclude that Alayne's task since it involves low repetition, low force movements with a considerable amount of down time namely 15 minutes per hour which was discretionary time where the muscles could be rested providing a variation from repetitive duties; is in fact low risk work. This is clearly reflected in the fact that her pain syndrome escalated at a time when she was under considerable stress from non-occupational and to a lesser extent occupation factors. Furthermore she was pregnant in the latter part of 1992 a known cause of exacerbation of her carpal tunnel syndrome. Alayne incriminated trimming as the predominant cause of her symptoms and there is little doubt that aches and pains can arise from this activity. One would however expect these aches and pains to wax and wane with the work process, to remain localised and not to escalate to level producing diffuse muscle tension in the upper limb, neck and shoulder region. Pain syndromes arise from multifactorial causation and did not directly arise from faulty ergonomics. From a therapeutic point of view it is important that Alayne understands that personal stress (ie. her stress reactivity] will have an influence upon the musculoskeletal system [as it had] inducing widespread tension in the muscles themselves and indirectly in the nerves. In the presence of her postural phenomena [forward drawn shoulders] this will result in crescendoeing and spread of the overuse symptoms. It is simply unfair and iniquitous to blame the work environment in its entirety for a condition [chronic pain syndrome] that will not respond to ergonomic intervention when this is the only activity that is undertaken. Clearly Alayne was under considerable stress in the work environment from her perception of being devalued where her skills as a technician were being under utilised. This would have had an untoward effect on stress levels undoubtedly inducing escalating muscle tension contributing to her cumulative trauma disorder. 9 To her credit Alayne has become independent of ACC and is now engaged in an active rehabilitation programme attending training college clearly now having improved coping abilities. She has learnt to focus on function and not on her pain which has meant that she has become self reliant through the development of self management skills. She is to be congratulated for the efforts she has made to help herself." Ms Forrest submitted: 1. That the Review Officer had failed to correctly interpret the legal tests required by section 7(1) and that there was insufficient evidence to enable her to make finding she did. 2. That the requirement of section 7(1)(a) is that the Review Officer had to be satisfied that the particular property or characteristic "caused or contributed to" the personal injury. That it is not sufficient that the employment task could merely cause or contribute to the injury. 3. That there was insufficient evidence before the Review Officer to satisfy the requirement that similar characteristics were not found to any material extent in the non-employment activities. 4. That there was insufficient evidence upon which the Review Officer could hold that the requirements of section 7(1)(c) were met. Ms Scott submitted: 1 . That while there was no specialist medical evidence available to the Review Officer, this problem had been remedied by the report of Dr Turner. 2 . That Mr Griffin had not inspected the workplace or examined the worker but gave a general statement on the cause of Carpal Tunnel Syndrome but indicated that the causes are difficult to ascertain. The issue falls to be determined under section 7(1) of the Act which states: "Personal injury shall be regarded as being caused by gradual process, disease, or infection arising out of and in the course of employment only if--- (a) In respect of a period that ended on or after the Ist day of April 1974, the employment task performed by the affected person, or the environment in which it was performed, had a particular property or characteristic which caused or contributed to that personal injury by gradual process, disease, or infection; and (b) The property or characteristic is not found to any material extent in the non-employment activities or environment of that person; and 10 (c) The risk of suffering that personal injury is significantly greater for persons performing that employment task in that environment than for persons who do not perform that task in that environment." In addition, it should be noted that pursuant to section 7(4) personal injury which is related to non-physical stress is precluded from cover under the Act. The history of this appeal commenced with the finding by the respondent that the worker had suffered a work injury. At that time the only medical evidence available was that of the appellant's General Practitioner who had diagnosed Carpal Tunnel Syndrome arising out of and in the course of her employment by the appellant. When the appellant applied for a review of the respondent's primary decision it submitted the assessment by ERGOS which had been made at the workplace but in the absence of the worker. However, it is interesting to note the conclusion made by the Assessor in that case which leaves open the possibility that OOS can be likely to occur in some people doing a particular job when it may not occur to others doing the same job. It certainly does not appear to take the issue any further and Mr Griffin's report simply outlines the possible causes for Carpal Tunnel Syndrome and the difficulty in making a diagnosis but without particular reference to the worker. Dr Turner has provided a very full report in a field in which he specialises. He examined the appellant and examined the workplace from which he concluded that the nature of the work with the appellant did cause or contribute to the onset of the worker's problems. The Review Officer heard the evidence from the worker who was then subject to an examination by the appellant's report. The Review Officer concluded that on the evidence there was nothing in the worker's non-work activities which contributed to or cause the problem. In the absence of any other evidence which might contradict that finding I am bound to accept the Review Officer's finding. The Review Officer also included that the on the evidence the nature of the appellant's industry was such that there were factors present in it whereby persons preparing that employment task in that environment are at a significantly greater risk in developing Carpal Tunnel Syndrome than persons who do not perform that task. I consider that on the basis of Dr Turner's report there is additional confirmation to support the Review Officer's finding on that issue. The Court has to be guided by the medical evidence in cases of this nature and the only persons who have examined the worker are Doctors Borwick and Turner. In addition, Dr Turner specialises in this field and in order to prepare his report inspected the work practices. 11 Accordingly I consider that the appellant has not established the onus on it that on the balance of probabilities the worker has not suffered a work related injury. The appeal is therefore dismissed. DATED at WELLINGTON this 2 day of July 1998 A W Middleton District Court Judge dc359-96.doc (nr)