Decision #120/09 - Type: Workers Compensation
Preamble
The worker is appealing a decision reached by Review Office of the Workers Compensation Board (WCB”) which determined that his bilateral carpal tunnel syndrome was not caused by or aggravated by his work activities as a driver. A hearing was held on October 28, 2009 to consider the matter.Issue
Whether or not the claim is acceptable.Decision
That the claim is not acceptable.Decision: Unanimous
Background
On September 25, 2007, the worker filed a claim with the WCB for bilateral wrist complaints, diagnosed as bilateral carpal tunnel syndrome (“CTS”), which he believed was caused from repetitive driving activities. The worker indicated that the steering wheel on the vehicle he drove was in a horizontal position and he drove with both wrists holding onto the sides of the steering wheel. He stated that his wrists were not really in a flexed position at this point but he did have to flex his wrists when turning the vehicle.
The worker reported that he noticed symptoms in both hands approximately three years prior, with the right hand being a little worse than the left. He reported that the pain and numbness in his hands gradually increased and by the spring of 2006, the numbness and tingling were constant.
On September 28, 2007, the employer’s representative opposed the position that the worker’s injury arose out of or in the course of his employment. The employer’s representative indicated that non-compensable factors contributed to the worker’s bilateral CTS condition such as smoking, diabetes, and body mass index.
On October 3, 2007, a WCB adjudicator spoke with the worker to gather additional information regarding the onset of symptoms in both his hands/wrists, medical and work history, driving ergonomics, and reporting of his difficulties.
Medical information on file showed that the worker underwent nerve conduction studies on August 27, 2007 which confirmed severe bilateral CTS. It also showed that the worker was diagnosed with a left fourth finger Dupuytren’s contracture in May 2001 which was repaired through surgery.
On October 23, 2007, the worker was advised that his claim for compensation was not acceptable as the WCB was unable to establish a relationship between his current bilateral wrist and hand difficulties as arising out of and in the course of his employment. The following factors were identified by the case manager in support of her decision:
· the worker’s job duties as a driver did not expose him to sustained repetition, excessive force, awkward positions and extreme vibration;
· the non-specific nature of the accident history provided by the worker; and
· the delays in reporting the accident.
On December 3, 2007, a union representative appealed the above decision to Review Office. The union representative outlined the worker’s work history and felt that the worker’s claim should be accepted by the WCB as either “…a justified claim related to previous employment activities, or that this claim be accepted as an aggravation/enhancement of an underlying condition caused in part with his operating a [vehicle].”
A rebuttal submission was received from the employer’s representative dated December 18, 2007. It was felt that “…the preponderance of evidence fails to establish any relationship between [the worker’s] bilateral Carpal Tunnel Syndrome and the operation of a [vehicle]. Further, there is also no credible evidence that would support [the union representative’s] contention that the operation of [a vehicle] has aggravated or enhanced an underlying condition.”
On January 7, 2008, Review Office advised all parties that it could not make a decision as to whether the claim for compensation should be accepted on the basis of an aggravation of a pre-existing condition as this issue had not been considered by primary adjudication. Review Office also asked primary adjudication to obtain more information to assist in the review of the claim.
On February 4, 2008, primary adjudication asked a WCB medical advisor to review the file in conjunction with the union representative’s submission of December 4, 2007 and to provide an opinion as to whether there was a relationship between the worker’s employment history and the development of CTS and whether there was a relationship between CTS and the worker’s right hand trigger ring finger and left trigger finger and tenosynovitis of the left flexor tendons.
In a response dated February 27, 2008, the WCB medical advisor stated the following:
· there was no evidence to show that the worker’s prior work duties contributed to the development of CTS;
· there was no apparent pre-existing CTS which could have subsequently been aggravated by the more recent workplace duties.
· the reference to driving vehicles with no power steering 20 years ago that required more force to grip and turn was not relevant as there was no record of CTS developing associated with these remote duties. The worker’s symptom onset was within the last 5 to 6 years when power steering was in use.
· there was no relationship between CTS and tendosynovitis/trigger finger.
· the medical advisor was of the view that the issue raised by the union representative did not substantiate the argument that workplace duties were a material contributor to the development of CTS.
· the attending physician stated on October 10, 2007, “the patient relates his CTS to his gripping (vehicle) wheel continually for many years driving…and I think this is a reasonable possibility of the cause.” The medical advisor indicated that this appeared to be speculation.
On March 4, 2008, the WCB case manager declined to accept responsibility for the worker’s bilateral wrist difficulties as being caused or aggravated by his current work duties. The decision was reached mainly on the opinion expressed by the WCB medical advisor on February 27, 2008.
On April 1, 2008, the union representative asked the case manager to review a specific WCB claim which was similar to the worker’s claim (i.e. drove for 28 years and developed CTS) that was accepted by the Appeal Commission. In the event that no change was made to WCB’s previous decision to deny the worker’s claim, it was requested that the case be referred to Review Office for consideration.
On May 8, 2008, it was determined by the WCB case manager that no change would be made to previous decisions of October 23, 2007 and March 3, 2008. The case manager indicated that all claims were adjudicated on their own merits and that the WCB was unable to provide information relating to the claim referred to on April 1, 2008.
On June 5, 2008, Review Office considered all file information which included a rebuttal submission by the employer’s representative dated May 23, 2008. Review Office stated that it accepted the diagnosis of CTS. It stated that it could not establish from the evidence that the worker’s bilateral CTS was due to his employment activities performed over some 21 years. It was not until 2001 when the worker began having symptoms and signs suggesting that he had median nerve compression.
Review Office accepted the opinion of the WCB medical advisor dated February 27, 2008.
Review Office stated it was unable to find that the worker’s employment tasks involving the operation of a steering wheel, whether it was a telescopic steering column or where the worker had to extend his arms due to his stature, to constitute highly repetitive, high force tasks which would lead to the development of CTS. It felt that the worker’s duties involved minimal force without extreme hand/wrist flexion, extension or repetition, with extra exertion/gripping applied periodically.
Review Office indicated that bilateral CTS typically suggested that employment was not causal in the development of this condition.
Review Office concluded that it was unable to find that the worker’s employment tasks were causally involved in the development of bilateral CTS or that his employment tasks “aggravated” his CTS resulting in the worker’s need for surgical treatment.
On June 1, 2009, the worker’s representative appealed Review Office’s decision to the Appeal Commission and an oral hearing was arranged.
Reasons
Applicable Legislation:
The Appeal Commission and its panels are bound by The Workers Compensation Act (the “Act”), regulations and policies of the Board of Directors. Subsection 4(1) of the Act provides:
4(1) Where, in any industry within the scope of this Part, personal injury by accident arising out of and in the course of the employment is caused to a worker, compensation as provided by this Part shall be paid by the board out of the accident fund, subject to the following subsections. (emphasis added)
The key issue to be determined by the panel deals with causation and whether the worker’s bilateral CTS, which became symptomatic in November, 2006, arose out of and in the course of his employment.
Worker’s position
The worker was represented by an advocate at the hearing. The position advanced on behalf of the worker was that his job duties involved more than just sitting in a driver’s seat all day and that there were numerous hand movements which could contribute to the development of CTS. His hands were constantly moving throughout his shifts in gripping the steering wheel to maintain control of the vehicle and in operating various controls which involved flexing and unflexing of the wrists. In addition, it was submitted that the suspension of the vehicle, the vibration through the driver’s compartment and the often cold temperature of the vehicle also contributed to the development of CTS.
At the hearing, the worker gave evidence regarding the scope of his duties as a driver. He had been employed as a driver for the accident employer for approximately 21 years. He described the various controls he was required to operate and how the manner of operation had changed over the last 5 years as new vehicle models were introduced. The worker also explained how he had difficulty in some vehicles with adjusting the driver’s seat to suit his short stature, and that at times he had to grip the steering wheel more tightly to remain secure in his seat. He showed the panel how he held the steering wheel (prior to his CTS surgery), which was in a palms down position at 3 and 9 o’clock, with the fingers and thumbs wrapped around the steering wheel and the wrists in a neutral position. There was also discussion of vehicle movement and how much the vehicle would shake, particularly at high speeds and in rough winter conditions. It was submitted that all of these factors contributed to the development of the worker’s bilateral CTS.
Employer’s Position
Two representatives from the employer were present at the hearing. It was submitted that the nature of the forearm activities associated with the worker’s operation of his vehicle were not those generally associated with the development of CTS. Typically, one would look for factors such as prolonged severe force through the wrist, prolonged extreme posture of the wrist, high amounts of repetitive movements and exposure to vibration and/or cold. In the present case, given the absence of any combination of such factors and given the existence of non-compensable factors known to predispose one to CTS (being smoking, age and high body mass index), it was submitted that the panel confirm the decision of the WCB.
Analysis
To accept the worker’s appeal, we must find on a balance of probabilities that he suffered injury by a workplace accident within the meaning of subsection 4(1) of the Act. In order to do so, we must find that his bilateral CTS arose out of and in the course of his work duties. Based on the evidence before us, we are not able to make that finding.
CTS is defined as the impairment of the motor and/or sensory function of the median nerve as it traverses through the carpal tunnel. It is caused either by intrinsic swelling of the median nerve or by extrinsic compression of the median nerve by one of the many surrounding structures of the wrist. CTS has a variety of causes. It can be caused by underlying systemic conditions such as rheumatoid arthritis, osteoarthritis, hypothyroidism and diabetes. Middle aged females, individuals with a high body mass index, smokers and people genetically pre-disposed to the development of CTS are also at increased risk for the development of CTS. It can also be caused by some work activities. There remains considerable debate in the medical literature as to what work factors may cause CTS. Occupational factors most commonly accepted to be associated with CTS include a wrist injury, frequent use of vibrating hand tools or any repetitive, forceful motion with the wrist bent, especially when done for prolonged periods without rest. It is generally considered that the greatest frequency of occupationally related CTS is found where the job duties involve high force and high repetition.
To decide this appeal, the panel must carefully examine the worker’s job duties to determine whether, on a balance of probabilities, they might have caused his CTS.
After considering the evidence before us, the panel is of the opinion that the worker’s CTS is not causally connected to his work duties. The job duties identified by the worker are not consistent with the type of duties typically associated with the onset of CTS symptoms. For the most part, the worker’s wrists were in a neutral position, and there was virtually no requirement for either high force or high repetition. There were no prolonged periods of loading the forearm muscles without an opportunity to rest. Although the worker was required to use his hands to operate the various controls of his vehicle, none of the actions appeared to be causative of CTS. We do not accept that gripping of the steering wheel or shaking/movement of the vehicle, as described by the worker, would cause CTS to develop. The panel also notes that the worker’s condition is bilateral, which suggests a non-work related etiology.
On a balance of probabilities, the panel is unable to relate the worker’s bilateral CTS symptoms to the work duties which were being performed by him. The worker’s appeal is therefore denied.
Panel Members
L. Choy, Presiding OfficerA. Finkel, Commissioner
P. Walker, Commissioner
Recording Secretary, B. Kosc
L. Choy - Presiding Officer
Signed at Winnipeg this 17th day of December, 2009