Decision #46/08 - Type: Workers Compensation

Preamble

In March 2007, the worker filed a claim with the Workers Compensation Board (“WCB”) for bilateral carpal tunnel syndrome (“CTS”) that she related to her work duties in an office setting. The worker’s claim for compensation was denied by primary adjudication and Review Office on the grounds that they could not relate the worker’s job duties to the development of her CTS condition. The worker disagreed and filed an appeal with the Appeal Commission and an oral hearing was held on February 28, 2008.

Issue

Whether or not the claim is acceptable.

Decision

That the claim is acceptable.

Decision: Unanimous

Background

In March, 2007, the worker contacted the WCB to file a claim for problems she was experiencing with her hands and wrists. She attributed her injury to the nature of her job duties which involved keying on a computer with both hands and using a mouse with her right hand. The worker stated she had been at her current job for 25 years. She said everyone at work knew she was having problems and that she wore splints at work. The worker indicated that she had the same problems before and made reference to a previous WCB claim from 1999.

The previous claim was filed in June, 1999 for pain, paresthesia and weakness in both hands, with symptoms being greater in the left than the right. The Tinel and Phalen tests were positive bilaterally. Wrist splints were prescribed and the worker was disabled from working effective June 2, 1999. The worker’s previously booked vacation time coincided with the period of disability, and she was not scheduled to return to work until September. On August 3, 1999, a nerve conduction study was performed which showed normal median motor and sensory conductions bilaterally. When she had a consultation with a surgeon, he opined that she likely had CTS but that the condition had improved due to being off work for the past three months. The worker returned to work on October 12, 1999.

In January, 2000, a work site assessment was performed by the employer and some changes were implemented at the worker’s work station.

In March, 2000, the worker had a relapse and reported increased pain and swelling in both wrists. Phalen and Tinel tests were both positive bilaterally. The worker stopped working effective March 24, 2000. While she was away from work and keyboarding, the worker’s symptoms settled. On June 20, 2000, another nerve conduction study was performed which again showed normal median nerve conductions bilaterally. By June 26, 2000, her family physician reported that she was asymptomatic. The worker was then on summer vacation and did not return to work until September 13, 2000. As the diagnosis of CTS was never confirmed by the nerve conduction studies, the 1999 claim was recorded to be a tendonitis claim due to repetitive use.

In 2007, when the worker filed the present claim, she advised the WCB that she first noticed her symptoms at about the beginning of May 2006. The soreness would come and go, depending on how hard she was working. She wore splints at work, but still would go home with sore hands after work.

Nerve conduction studies taken on June 1, 2006 revealed bilateral median mononeuropathy at or distal to the wrists which electrographically appeared to be mild bilaterally.

In a report to the treating physician dated December 4, 2006, the plastic surgeon noted that the worker presented with a history of bilateral CTS and that she had it for a number of years. He noted that the worker did data entry and that her symptoms were getting slowly worse over time. He noted that nerve conduction studies were reported as being moderate. He said the worker was a good candidate for surgical decompression.

The worker was contacted on April 24, 2007. She indicated that her 1999 compensation claim was accepted for tendonitis. She advised that her computer set up was ergonomically correct. The keyboard was in front of her with the mouse on the right. She said her work duties do not expose her hands to excessive force, pressures, gripping or awkward positions. Her hands are relatively flat and there is no pressure on her wrists or hands while typing.

The employer’s accident report indicated that the worker worked on a computer for 9 hours a day and also answered the phone and made calls. The worker did not wear a head set unless she had to make multiple phone calls. She received and made about 20 to 25 calls per day. Her phone was on the right hand side. She also used the mouse about 15 percent of her day and the mouse was on the right side of her desk. Her desk was set up in June 2005. The worker had a proper chair and received an ergonomic keyboard in January of 2007. She also had a wrist support under her keyboard. The employer indicated that the worker wore splint support on both wrists since 2006.

On April 24, 2007, the worker was advised that the WCB was denying her claim for compensation on the grounds that it could not relate her bilateral CTS condition to her described job duties. The adjudicator noted that the worker’s job duties involved some repetition but there was no awkward hand positioning or force that would be causative for the development of bilateral CTS.

On May 16, 2007, the worker appealed the above decision to Review Office. She outlined her view that her wrists were already damaged prior to her getting the ergonomic keyboard in February 2007. She said her job involved constant repetition of wrist and hand flexion when she typed or wrote with a pen or used a mouse. She stated that she had worked at a variety of occupations with her employer since 1982 that necessitated the use of a typewriter or keyboard that was not ergonomically designed. Since May 2006, her symptoms had gotten worse.

On May 17, 2007 surgical repair was performed on the right wrist. Surgery on the left wrist was scheduled for September, 2007. Responsibility for the surgeries was not accepted by the WCB.

In a decision dated May 31, 2007, Review Office confirmed that the claim for compensation was not acceptable. Review Office outlined its view that the worker had several non-work related risk factors which were known to contribute to the development of CTS. These included gender, age and body habitus. Review Office acknowledged that the worker’s job duties may be repetitive in nature but did not find that her work activities involved high force and extreme wrist positions concurrent with the repetition. Review Office noted that the worker had a history of waxing and waning symptoms and had complete resolution of carpal tunnel like symptoms in 2000. If work was a causal factor in the development of CTS, one would expect that the symptoms would persist over the years as the worker continued to work in this environment. Review Office concluded that the evidence did not establish that the worker suffered a personal injury by an accident arising out of and in the course of her employment.

On November 2, 2007, a worker advisor appealed Review Office’s decision to the Appeal Commission and a hearing was arranged.

Prior to the hearing, the worker advisor provided the Appeal Commission with a letter from the treating plastic surgeon. In his report dated October 29, 2007, he stated, in part, “Based on the probabilities and her temporal relationship and description of her job, it is very likely that [the worker’s] workplace activities at least enhanced her carpal tunnel syndrome or possibly even caused it.”

Reasons

Applicable Legislation:

The worker is employed is employed by a federal government agency or department and her claim is therefore adjudicated under the Government Employees Compensation Act (“GECA”). Under the GECA, an employee who suffers personal injury by an accident arising out of and in the course of employment is entitled to compensation.

The key issue to be determined by the panel deals with causation and whether the worker’s CTS which was diagnosed in June 2006 arose out of and in the course of her employment.

Worker’s position

The worker was represented by an advocate at the hearing. The position advanced on behalf of the worker was that the job duties being performed by the worker since she started working for the employer in 1981 were repetitive and over time caused the CTS. It was argued that although there may not have been force involved, the repetitive nature in and of itself could cause the injury. With each movement, micro damage was being incurred to that particular part of the body, and over time, it simply wore out. At the very least, the repetitive duties would have enhanced the condition, leading to the need for the two operations.

At the hearing, the worker testified that when she started with the employer in 1981, her duties were basically typing all day. She started off on a manual typewriter, then went to an electronic typewriter and then to a word processor. At the time, there were no provisions made for proper ergonomics and her wrists would be in flexion as she worked. The worker remained in the word processing job for ten to fifteen years. Over that time, she would get fatigue in her hands and tightness in her shoulders, but she did not miss any time from work because of these symptoms.

In the late 1980’s and early 1990’s, the worker took some time off work when she had her children. When she was at home, her symptoms were much better and she did not have any symptoms of burning or aching in her wrists or hands.

In approximately 1995, the worker was promoted and her job duties changed. She still did a fair bit of typing, but it was not as intense as word processing was. Her job now involved keyboarding, some telephone contact and data retrieval on the computer system, which required using a mouse. In this position, she would get tingling in her fingers, and aching and burning in her hands and wrists. Towards the end of the week, her symptoms would increase. She would treat the symptoms by resting her hands when she got home and applying ice.

By 1999, the symptoms and pain became more intense to a point where it was a daily occurrence. She also started to have shooting pain from the wrist to the elbow, and swelling. Wrist splints were prescribed by her family physician, and her first WCB claim was filed.

She returned to work in the fall of 1999, and continued her duties, often using wrist splints while she worked. She also continued the pattern of taking extended periods of nine to ten weeks off during the summers. She also had five weeks of vacation time and she would take a week at a time throughout the year, during which time she could give her hands a rest.

In 2001, she commenced a new position. With the new position, the nature of the worker’s duties did not change but the position was much busier and more stressful. She did receive some ergonomic supports for her wrists at work, but these were not provided until more recently.

Analysis

To accept the worker’s appeal, we must find on a balance of probabilities that she suffered injury by a workplace accident. In order to do so, we must find that her bilateral CTS arose out of and in the course of her work duties. Based on the evidence before us, we are 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, overweight individuals, 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 her CTS.

After considering the evidence before us, the panel is satisfied that the worker’s CTS was causally connected to her work duties. In reviewing both the 1999 and 2006 WCB claim files, the panel notes that there were CTS signs present from an early date. In 1999, she tested positive for Tinel and Phalen signs in both wrists. At that time, she had been performing repetitive keyboarding and computer duties for approximately 18 years in an environment where little attention had been paid to ergonomic adjustments. Although the nerve conduction studies performed in August 1999 and June 2000 showed normal nerve conduction bilaterally, in both cases, she had been away from work for several months prior to the tests being conducted. It is possible for CTS symptoms to improve when the offending activity is avoided and the panel finds that this is what in fact occurred. When the worker returned to work after her 1999 claim, she continued to rely on her wrist braces and she carried on her pattern of taking extended absences from work for multiple weeks at a time, during which periods her wrists rested and recuperated.

The October 29, 2007 report of the treating plastic surgeon indicates that although there may not be extreme wrist positions, this does not necessarily mean that the worker could not develop CTS from her repetitive activity. Some patients may require less of the offending risk activities to cause carpal tunnel syndrome. Based on the temporal relationship and description of her job, it was his opinion that the workplace activities at least enhanced the CTS or possibly even caused it. The panel accepts this opinion, based in particular on the extended periods over which the worker had experienced right and left wrist difficulties, including the ongoing use of wrist braces.

On a balance of probabilities, the panel finds that the worker’s wrist problems in 2006 were connected to the symptoms she experienced in 1999. The worker had a lower threshold and was predisposed towards CTS symptomatology. Her job duties of keyboarding, writing and mousing worsened her condition. Given the foregoing, we find that the worker’s claim is acceptable.

The appeal is allowed.

Panel Members

L. Choy, Presiding Officer
A. Finkel, Commissioner
M. Day, Commissioner

Recording Secretary, B. Kosc

L. Choy - Presiding Officer

Signed at Winnipeg this 28th day of March, 2008

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