WORKPLACE SAFETY AND INSURANCE APPEALS TRIBUNAL

Transcription

1 2002 ONWSIAT 254 WORKPLACE SAFETY AND INSURANCE APPEALS TRIBUNAL DECISION NO. 140/01 [1] This appeal was heard in Thunder Bay on January 18, 2001, by Tribunal Vice-Chair N. McCombie. THE APPEAL PROCEEDINGS [2] The worker appeals the decision of Appeals Resolution Officer B.J. Martlin, dated May 25, 1999, rendered without an oral hearing. That decision concluded that the worker did not have entitlement for an condition that he claims arose out of and in the course of his employment. [3] The worker appeared and was represented by J. Ranger, a private consultant. The employer attended in the person of its occupational health nurse, B. Rogers. THE EVIDENCE [4] The material included in the Case Record prepared by the Tribunal Counsel Office (Exhibit #1) was considered. In addition, the following were considered: Exhibit # 2 Tribunal s Vice-Chair Registrar Certification letter; Exhibit # 3 Correspondence from Ms. Ranger with enclosures; Exhibit # 4 Further correspondence from Ms. Ranger; Exhibit # 5 a detailed report from the Occupational Health Clinic for Ontario Workers dated January 15, 2001; Exhibit # 6 Post-Hearing Addendum with the parties submissions [5] Oral evidence was heard from the worker. No oral submissions were made at the hearing, but they were provided post-hearing in Exhibit #6. THE ISSUES [6] On behalf of the worker, Ms. Ranger is claiming that there is a causal relationship between the degenerative disc disease condition in the worker s neck and the work that he was performing for the employer. THE REASONS (i) Background [7] The worker was a heavy equipment operator for a forestry company. He had been employed in this capacity since May 1970, more than 25 years with the employer.

2 Page: 2 Decision No. 140/01 [8] The worker testified that he was involved in various aspects of logging, including operating a skidder, a cutter, a feller-buncher and a bulldozer. This work would often be carried out on rough terrain, terrain that was rocky or swampy. [9] In 1973, the worker suffered a low back sprain for which a brief period of lost time benefits was paid. A recurrence of this injury was claimed, and denied, in In addition, there were several no lost time claims filed between 1972 and 1987 concerning his low back. [10] In July 1996, the worker began work as a backhoe operator. He testified that he does not have problems with this job as the machine was stationary with a rotating cab and he was not required to twist and turn his neck. [11] In April 1998, the worker filed a Worker s Report of Injury or Disease. This report indicates that there was a gradual onset of pain in neck and upper back followed by dizziness caused by certain movements. Pain has increased considerably since having carpal tunnel. I have worked as a heavy equipment operator off and on since date of hire I have also worked as a feller for 5 to 6 years. [12] The date of injury given on this form is one year earlier, May 28, 1997, with lost time reported from June 15, In answer to the question as to when the pain was first noticed, the worker reported that it was after his first surgery for a carpal tunnel syndrome in He also notes the 1996 change in jobs to the backhoe operator, due to constant neck-upper back pain. [13] A Board investigator interviewed the worker and received further details about his job history and onset of symptoms. The Board denied the claim at that time on the grounds that there had been no medical attention sought for his neck between 1994 and It was concluded that there was no proof that the worker s occupation was a significant contributing factor in the development of his cervical degenerative disc disease. [14] The Appeals Resolution Officer confirmed this reasoning, noting the delay in reporting and the lack of medical support for a relationship between the worker s employment and the onset of symptomatic degenerative disc disease. (ii) The medical evidence [15] There is an orthopaedic report from Dr. G. A. Porter, dated February 22, 1993, concerning the worker s low back complaints. This is several years before the claim was filed. That report, in addition to the low back, also refers to x-ray evidence of degenerative changes in the cervical spine, over two or three levels with flattening of the cervical curve. Despite this, Dr. Porter was of the opinion that this is fairly well manageable at the present time and would allow him to continue to work in the capacity as a feller buncher operator. [16] By June 6, 1997, when further x-rays were taken, the finding was severe disc space narrowing from C3-C4 to C5-C6.

3 Page: 3 Decision No. 140/01 [17] At the time of the Appeals Resolution Officer decision, the worker relied on a report from Dr. A.K. Chaudhuri, a neurological surgeon. Dr. Chaudhuri saw the worker on March 13, 1998, and concluded that: This patient has moderately severe mid cervical spondylosis and degenerative changes. From the extent of the location this very likely is occupation related. This patient has worked in the bush and operated a tractor on rough ground for many years and repetitive vibrations of clinical trauma very likely lead to the degenerative process. At the present time there is no evidence of radiculopathy or myelopathy and there is no indication for surgical treatment. He is managing quite well and is working full time. He should continue to watch for limitations and should be advised by a therapist. At the present time, no further investigations are indicated. He has been seen by an orthopaedic surgeon, Dr. Puskas as he has informed me and apparently Dr. Puskas is going to follow him and see him if he shows any deterioration. I have not made any further appointment and if he shows any deterioration, hopefully you would be able to refer him to Dr. Puskas. [18] In a subsequent report from Dr. Chaudhuri, dated April 19, 1999, he repeated his opinion that the degenerative changes could be occupation related in view of the nature of work over the years. In this report, he noted that there was no exact length of time of vibratory trauma that led to degenerative changes, but speculated that probably ten to fifteen years would likely lead to disc degeneration. [19] Subsequent to the Appeals Resolution Officer decision, Ms. Ranger obtained an extensive opinion from the Sudbury Occupational Health Clinic for Ontario Workers ( OHCOW ). This opinion is dated January 15, 2001, three days before the hearing. This report was obviously outside the three week window. It is, however, a substantive report that squarely addresses the issue before me. As such, I accepted the report and gave Ms. Rogers the opportunity to respond post hearing. [20] The OHCOW report consists of: a 12 page medical opinion from Dr. J.E. Andersen; a copy of a September 13, 2000 report from Dr. R. House of the occupational health programme at St. Michael s Hospital in Toronto; a 12 page ergonomic assessment, dated January 9, 2001, carried out by the OHCOW ergonomist [21] These reports, as noted, are quite detailed. However, much of that detail establishes the history, which I have already noted, a diagnosis of cervical degenerative disc disease (which is not in dispute) and comments concerning the worker s low back injury in 1973 and subsequent symptoms (this is not an issue before me). In addition, the ergonomist s report reviews at some length the mechanics of degenerative disc disease and the general ergonomic risk factors. [22] The ergonomist then postulates that the worker would have been exposed to 32,500 hours of whole spine vibration. He bases this figure on the following supposition: 26 years of exposure ( ) x 50 weeks per year x 5days per week x 5 hours per day [23] Based on this equation, the ergonomist concludes:

4 Page: 4 Decision No. 140/01 It is probable that [the worker s] work activities as a heavy equipment operator may have resulted in his neck and back problems with years of exposure. [24] Dr. Andersen adopts this conclusion, noting that the worker has been a forestry worker for approximately 40 [sic] years. He also notes that Dr. House reiterates his exposure to wholebody vibration over many years and attributes his neck pain to his vibration exposure. [25] Dr. House is a specialist in occupational medicine. His report notes that the worker was a heavy equipment operator, for the past 34 [sic] years. For most of this time, he was required to drive a tractor over very uneven terrain with resultant whole body vibration exposure... the occupational history is significant for exposure to whole body vibration for an extended time and this may be associated with exacerbation of osteoarthritis of the spine. (iii) The caselaw [26] Neither party referred to Tribunal caselaw in this area. However, there have been a number of cases which considered the effect of whole body vibration on the progression of degenerative disc disease. [27] In Decision No. 559/87 (1988), 9 W.C.A.T.R. 103, the Panel undertook an extensive review of the medical literature. This review, it should be noted, related to the low back, not to the neck. It was concluded that there was not enough evidence to support a conclusion that the vibrations from long distance truck driving the worker s job in that case caused degenerative disc disease. However, truck driving was found to have aggravated an underlying, pre-existing, asymptomatic degenerative disc disease or some other pre-existing special susceptibility. The injuring process was the dynamic, cyclical, excessive stress on the lumbar region from enforced sitting in a whole body vibration environment. The worker s condition was therefore found to be compensable. [28] This literature review was revisited at the request of the Panel in Decision No. 373/91 (December 14, 1992), a decision that, again, involved the low back. In an appendix to that decision, Dr. B.W. Malcolm, an orthopaedic specialist, agreed that the review undertaken in Decision No. 559/87 was a complete one. His conclusions upon further review were that the literature did appear to support a relationship between early degeneration in the lumbar spine and whole body vibration. [29] However, as the Panel noted, the studies have not yet come to firm conclusions on exposure/response relationships between whole body vibration and spinal disease - and he [Dr. Malcolm] concluded that the current understanding of this relationship is essentially the same as the understanding at the time of the Decision No. 559/87 review. In our view, the epidemiological studies do not provide sufficient evidence for us to conclude that this worker s 1986 back disability resulted from the nature of his work. The studies raise the possibility that whole body vibration can cause back disability in some cases. But, we must look at the facts of this case and consider both the probability of any contribution from whole body vibration, and the extent of any such contribution.

5 Page: 5 Decision No. 140/01 [30] Decision No. 160/95 (September 27, 1995) does deal with cervical disc degeneration. That Panel too sought the opinion of a Tribunal assessor, in that case, Dr. D.J. O Neil, another orthopaedic surgeon. The Panel quoted the following from Dr. O Neil s report: After reviewing [the worker s] medical reports, and his type of work, it is my opinion that this gentleman s work activities would contribute to the development of degenerative disease of the cervical spine. It is also my opinion that his work activities as a scoop tram operator, which involves impact loading of his neck with the neck in a fully rotated position to the right and left, would most probably accelerate the process of the degenerative disease in his cervical spine. It is also my opinion on reviewing the medical reports on file that there is no connection between his two work place accidents and his two-non-compensable accidents and the course of his cervical disc disease. [31] The Panel expressed some concerns with Dr. O Neil s explanation of his conclusions, but nevertheless, decided, on a benefit of doubt basis, that the worker s neck condition was related to his job as a driller scoop tram operator. [32] Finally, again dealing with a low back condition and with a forestry worker, Decision No. 1539/98 (January 7, 1999) concluded that, Machines built to carry heavy loads requiring heavy construction cannot possibly provide a smooth vibration-free ride. It must also be kept in mind that vibration is not only caused by the travelling over rough terrain, but that loading and unloading charges of logs by grapple or bucket jars and jolts the machine. I have also been provided [with]medical excerpts on whole body vibration, vibration of the spine and low back pain, as well as vibration and the human spine [that] show that low-back pain is more common in workers exposed to vibration than the general population.... Given the worker s pre-employment symptom-free history, the nature of his employment as a loader operator exposed to vibration, the medical fact that such vibration can likely render an already degenerative disc disease symptomatic, and given Dr. Dakin s and the Board physician s opinions that the condition was aggravated by his employment, I find that the worker is entitled to compensation for the impairment of his lower back resulting from his employment. [33] The Tribunal has a discussion paper concerning cervical degenerative disc disease (Neck Pain and Related Symptoms: Cervical Disc Disease, written by Dr. J.F.R. Fleming, April 1997). This paper does not address whole body vibration, but does make the following point: Repetitive stress to the cervical spinal column may result from activities such as in carrying loads on the head (as in some societies), in football, or in high divers (such as in Acapulco). Although premature aging (degenerative) changes are seen in many of the spines of such individuals, pain or other symptoms are very uncommon. Repetitive stresses to the cervical spinal column also occur in individuals with neurodegenerative disorders such as dystonia or torticollis, who suffer from repeated, sometimes quite violent, uncontrolled writhing and twisting movements of the neck, yet neck pain is remarkably uncommon in these individuals. Repetitive neck movements or prolonged awkward positioning of the neck in a workplace activity are similarly well tolerated by most individuals, although they may be associated with muscular aches and pains in some.

6 Page: 6 Decision No. 140/01 [34] In addition to these cases and several others at the Tribunal, I note that British Columbia has issued a number of appeal decisions concerning whole body vibration and lumbar problems. Of particular interest is Decision , (16 WCR 265) (December 6, 1999). This decision conducted a thorough review of the literature and concluded that: The worker s appeal is allowed. His lumbar spine degeneration has been significantly aggravated by his employment as a heavy equipment operator since 1957, and an occupational disease claim should be accepted. [35] This decision notes that there are regulations in British Columbia concerning whole body vibration: That exposure to whole body vibration may be problematic is illustrated by the fact that the Occupational Health and Safety Regulation addresses exposure to whole body vibration. Parts 7.24 to 7.31 of that regulation issued by the Workers Compensation Board provide that employers must evaluate whole body vibration in accordance with three published standards or another standard acceptable to the Board. Where practicable, equipment which meets the guidelines must be used in preference to equipment which produces higher levels of vibration. Equipment which produces levels of vibration above the recommended guidelines must be labelled to identify the hazards. The employer must ensure that a worker exposed to excessive levels of vibration is informed of the nature of the hazard and possible adverse effects. [36] This decision refers to the above Ontario case, Decision No. 559/87, but had some concern: The Ontario case noted above involves acceptance of a back disorder as result of a relatively brief period of exposure that was much shorter than the five years referred to in the Dr. B report or the 10 years found in the German guideline. While the decision is of interest in that it reviews some of the literature and testimony, we would be reluctant to rely on the outcome for guidance in this case given the brief period of exposure. [37] Also of interest is a major study by the U.S. National Institute of Occupational Safety and Health ( NIOSH ) 1. Again, with respect to low back injury, this study was supportive of a relationship with whole body vibration: Conclusions: Whole Body Vibration There is strong evidence of a positive association between exposure to WBV [Whole Body Vibration] and back disorder. Of the 19 studies reviewed for this chapter, four demonstrated no association between WBV and back pain. Possible explanations for these results included use of subjective exposure assessments that perhaps resulted in misclassification of exposure status and, in one cross-sectional study, operation of a healthy worker selection effect (where those with higher exposures dropped out of the study group). The remaining 15 studies were consistent in demonstrating positive associations, with risk estimates ranging from 1.2 to 5.7 for those using subjective exposure measures, and from 1.4 to 39.5 for those using objective assessment methods. Most of the studies that examined relationships in high-exposure groups using detailed quantitative exposure measures found strong positive associations and exposure-response relationships between WBV and back pain. These relationships were observed after adjusting for age and gender, along with several other covariates (which, depending on the study, may have included smoking status, anthropometric measures, recreational activity, and physical and psychosocial work-related 1 "Musculoskeletal Disorders (MSDs) and Workplace Factors: A Critical Review of Epiderniologic Evidence for Work- Related Musculoskeletal Disorders of the Neck, Upper Extremity, and Low Back"; July 1997

7 Page: 7 Decision No. 140/01 factors). This evidence is supported by results observed in many earlier epidemiologic investigations that have been summarized in other reviews. Laboratory studies have demonstrated WBV effects on the vertebrae, intervertebral discs, and supporting musculature. Both experimental and epidemiologic evidence suggests that WBV may act in combination with other work-related factors such as prolonged sitting, lifting, and awkward postures to cause increased risk of back disorder. It is possible that effects of WBV may depend on the source of exposure. For example, in the studies reviewed for this document, ORs [Odds ratios] were particularly high for helicopter pilots. It was not possible to determine differences for other types of vehicles automobiles, trucks, and agricultural, construction, and industrial vehicles) 2. [37] However, with respect to neck problems, the study noted: We conclude that there is insufficient evidence to support an association between vibration and neck or neck/shoulder MSDs [Musculoskeletal Disorders]based on strength-ofassociation criteria. Too few studies of neck or neck/shoulder MSDs have examined the relationship between exposure to vibration and to draw any conclusions about their relationship. 3 (iv) Conclusions [38] It is clear from the evidence that the worker does have severe degenerative disc disease ( DDD ) in his neck. It is also clear, from all the general medical evidence that, while DDD is a typical part of the aging process in the majority of cases it is not symptomatic. [39] The question of why this worker s DDD may be symptomatic is addressed in the reports submitted on his behalf. [40] Dr. Chaudhuri and Mr. Schell s reports implied that the worker s employment may have been a cause of the degenerative changes in his neck, whereas Dr. House suggests that whole body vibration may have exacerbated the worker s DDD. Some Tribunal cases and the BC case discussed above have also accepted that whole body vibration may aggravate or accelerate an underlying lumbar condition. None of these decisions, that I am aware of, has accepted that vibration is a cause of DDD. [41] That being the case, and considering the lack of supporting literature in his report, I cannot accept Dr. Chaudhuri s implication that this worker s condition was caused by his work. [42] It is also evident, however, that lumbar DDD may be aggravated by occupations such as operating heavy machines on rough terrain, although there is little evidence in the literature for a relationship between whole body vibration and cervical DDD. [43] Dr. House does suggest that exposure to whole body vibration for an extended time and this may be associated with exacerbation of osteoarthritis of the spine. [emphasis added] His report, however does not cite the any authority for this proposition. [44] There is also a concern, as noted by Ms. Rogers, that the medical practitioners relied on highly inaccurate estimates of the worker s exposure to whole body vibration. In her 2 Ibid. Chapter 6. 3 Ibid. Chapter 2. [emphasis in original]

8 Page: 8 Decision No. 140/01 submission, for example, the 32,500 hours cited by Mr. Schell would be more like 9,850 hours, based on her information. [45] On the other hand, the medical reports from various doctors are supportive of a relationship in this worker s case. And, as noted, there is no doubt that the worker was exposed to whole body vibration combined with constant rotation and craning of the neck, for many years on and off. While it was not the 40 years suggested, for example, by Dr. Andersen, it was not, insignificant. [46] There is general evidence that this kind of activity can aggravate damage to the lumbar spine. This is significant enough that one jurisdiction, British Columbia, regulates worker exposure to whole body vibration. [47] In weighing all of these factors, I am of the view that the totality of the evidence in favour of and opposed to a casual connection, on an aggravation basis, is approximately equal in weight. As such, the benefit of doubt provision in section 4(4) of the Workers Compensation Act (also found at section 119(2) of the Workplace Safety And Insurance Act, 1997) applies and the appeal should be granted. THE DECISION [48] The appeal is allowed. The worker s cervical degenerative disc disease was aggravated by his long term occupation as a forestry worker exposed to whole body vibration straining of the neck. DATED: This 31 st day of January SIGNED: N. McCombie.