Decision #163/11 - Type: Workers Compensation

Preamble

The worker is appealing the decision made by the Workers Compensation Board ("WCB") which determined that her bilateral carpal tunnel syndrome ("CTS") did not arise out of and in the course of her employment. A hearing was held on November 4, 2011 to consider the matter.

Issue

Whether or not the claim is acceptable.

Decision

That the claim is not acceptable.

Decision: Unanimous

Background

The worker filed a claim with the WCB for injury to both her hands that she related to her work duties in housekeeping with the accident date of October 1, 2009. The worker described her job duties as follows:

  • Washing cabinets and counters
  • Sweeping and mopping floors
  • Cleaning ovens, fridges and bathrooms
  • Dusting from floor to walls
  • Cleaning windows
  • Moving items to do more cleaning jobs

The worker advised the WCB that she first noticed symptoms with her hands and arms in the fall of 2009. The worker noted that her symptoms are predominantly in her left hand and slightly in her right hand. Her right hand symptoms increased however when she "knocked" her hand on July 27, 2009. The worker believed the difficulties with her hands were related to her job duties in general as well as gripping of the mop and scrubbing.

The worker's claim was accepted based on the diagnosis of bilateral CTS and benefits were paid to the worker.

On September 9, 2010, a second WCB case manager requested a worksite assessment by a WCB rehabilitation specialist to get a better understanding of the job duties and the physical demands performed by the worker in her position.

On September 10, 2010, the WCB adjudicator met with the worker to discuss her claim. The worker denied any difficulties with CTS prior to working with the accident employer.

A worksite and job analysis was carried out on September 22, 2010 and the assessment results are contained in a memorandum to file dated September 28, 2010.

By memorandum dated September 29, 2010, the WCB medical advisor made the following comments:

"New information on file includes detailed job description. There is no use of vibrating tools, there is no repetitive grasping or finger and wrist repetitive resisted movement. Rather, the job describes a great variety of tasks, with no constant repetition. In the performance of such tasks, more stress of grasping would be expected on the dominant hand. It is noteworthy that the WCB is more developed on the non-dominant hand.

It is concluded that the development of CTS is probably not related to workplace activities in this case. The etiology is multi-factorial in most cases…It is probable that CTS would have developed to this degree in this worker, even in the absence of work activities."

Following consultation with a WCB medical advisor, the worker was advised on October 5, 2010 that the WCB was unable to accept responsibility for her bilateral CTS. The case manager indicated to the worker that she was unable to establish that her work duties involved the anatomical movements required for her condition.

A worker advisor, acting on behalf of the worker, asked for reconsideration of the October 5, 2010 decision and submitted a medical report from the treating neurologist dated December 15, 2010 to support that there was a relationship between the worker's job duties and the development of her bilateral CTS and the need for surgery. The neurologist did not agree with the September 29, 2010 opinion of the WCB medical advisor and stated:

"The development of CTS is probably not related to work activities in this case…" I disagree with this medical opinion. It was a change in her work duties to include washing walls that preceded the symptoms of carpal tunnel syndrome. While it is true that she is female, there are no other "non-work related factors" as listed in your letter. In work related factors "high force" and "repetitive activity…such as twisting, gripping…" are involved while she uses a mop. Gripping implies sustained/prolonged grip which is a described risk factor for the development of carpal tunnel syndrome. The left sided predominance is explained by her use of the mop with the left hand as the "power hand". Other activities performed such as wall/window washing are observed to be shared between the left and right hands. This involves periods of wrist extension identified as a work risk factor in your list. This is supported by the summary of videos/photos…The development of carpal tunnel syndrome was preceded by an increase in work demands suggesting a temporal association. She did not exhibit symptoms of carpal tunnel syndrome before this change. On the balance of probabilities, the carpal tunnel syndrome would not have developed in the absence of work activities." (emphasis in original)

On February 23, 2011, the WCB case manager determined that no change would be made to the October 5, 2010 decision. The case manager indicated to the worker advisor that it was her opinion that the tasks performed by the worker did not include the anatomical movements the WCB recognized as occupational factors for the development of bilateral CTS. The worker's job duties were varied significantly throughout the day, with the currently accepted definition of repetitive, forceful or awkward movements not established. On May 13, 2011, the worker advisor appealed the decision to Review Office.

On July 6, 2011 Review Office determined that the worker's CTS condition did not arise out of or in the course of her employment and confirmed that the claim for compensation was not acceptable. Review Office indicated that some of the job duties performed by the worker required full flexion of the wrists but the motion would not always be considered forceful. The job duties did not require forceful motion with the wrist bent for a prolonged period of time as the worker's duties varied and she alternated between using her left hand and her right hand. Review Office noted that the worker was right hand dominant but used both hands to perform her work duties. A review of the work duties did not provide an explanation as to why the CTS would be worse in her non-dominant hand. It was felt that the job duties did not have the degree of sustained repetition, forceful, or awkward movements to be considered causal in the development of CTS. On August 30, 2011, the worker advisor appealed Review Office's decision to the Appeal Commission and a hearing was arranged.

Following the hearing, the appeal panel requested a copy of the worker's 2009 compensation claim for bilateral shoulder difficulties. A copy of the 2009 claim was then forwarded to the interested parties for comment. On November 4, 2011, the panel met further to discuss the case and render its final decision.

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 arose out of and in the course of her employment.

Worker’s position

The worker was accompanied by a worker advisor at the hearing. It was submitted that the worker's work duties entailed the occupational work factors which are recognized in the development of CTS. Her work duties involved repetition, force and awkward postures of the wrist which were extended to the end of range of motion and involved forceful twisting and gripping. The work being done by the worker had to be fast-paced as her workload was greater than normal. This caused her wrists to swell and develop CTS. It was also submitted that the CTS symptoms arose while the worker was in the course of her employment and that there was an explanation as to why the CTS was worse in her non-dominant hand. As the evidence supported on a balance of probabilities that the worker's personal injury of CTS did arise from the physical aspects of her workplace duties, her claim should be accepted.

Analysis

To accept the worker’s appeal, we must find on a balance of probabilities that she 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 her bilateral CTS arose out of and in the course of her 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 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 her bilateral CTS.

After considering the evidence as a whole, we are unable to find that the work duties contributed to the CTS, either causally or as an aggravation.

At the hearing, the panel carefully reviewed the duties being performed by the worker during her employment with the accident employer. She started her job at the end of January 2009, and although she was supposed to be assigned to a three person work crew, for most of her period of employment she worked with only one other person. For the first couple of weeks, there were three, but then their third person left and she was never replaced. Other cleaning crews had three people assigned to do the work, but the worker and her partner had to do all the work themselves. It was evident to the panel that the worker and her partner had to work at a fast pace in order to finish the work assigned to them each day. They had to work harder than the other crews and did not have time to waste.

Despite the fast pace of the work, however, the panel's overall impression was that the duties being performed by the worker were not the kind which are typically associated with the development of carpal tunnel syndrome. The worker did describe some tasks which involved flexion and extension of the wrists; however, these tasks were not performed for sustained lengths of time. The worker’s job duties were varied and only seldom was she required to maintain a certain position for very long. For most tasks, a significant amount of force was not required. The jobs which the worker described did not involve the degree of repetition, force, or awkward movement which would typically be associated with CTS.

In his letter of December 15, 2010, the treating neurologist identified "power hand" duties which he felt contributed to the worker's CTS and explained the left-sided predominance. The panel questioned the worker regarding the use of a mop with left-sided power. The worker's evidence was that these mop duties were performed when she cleaned bathrooms, and in particular, the tile bathtub walls. The panel did have the opportunity to view videos of the worker's job duties, that were in the claim file, including this particular job activity. Her normal rotation was that one day she would wash bathrooms, and the next she would do the kitchen area. Both she and her partner would clean the living room area together. It would therefore appear that the worker would only have been performing the power hand duties every other day, and even then, only for the limited amount of time which it would take to clean the bathtub walls. The panel is not convinced that this pattern of work entailed the degree of sustained awkward wrist positioning with force, which would cause CTS. We also note that the worker's cleaning tasks were varied and her wrists would have opportunity to rest and recover from the awkward positioning as she moved from one area to the next.

The panel also notes that part of the history relied upon by the neurologist was not accurate. The neurologist's information was that the worker's CTS was preceded by an increase of work demands and he therefore concluded that there was a temporal association. The neurologist believed that the worker had only been recently short-staffed when her symptoms began. In fact, the worker had been working short staffed since February 2009. Her report to the WCB was that she first noticed her symptoms in the fall of 2009.

Based on the foregoing reasons, the panel is unable on a balance of probabilities to relate the worker’s bilateral carpal tunnel syndrome to the work duties which were being performed by her as a cleaner. The worker’s appeal is therefore denied.

Panel Members

L. Choy, Presiding Officer
A. Finkel, Commissioner
C. Anderson, Commissioner

Recording Secretary, B. Kosc

L. Choy - Presiding Officer

Signed at Winnipeg this 6th day of December, 2011

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