Decision #28/11 - Type: Workers Compensation

Preamble

The worker filed a claim with the Workers Compensation Board ("WCB") for left wrist and hand difficulties that he related to his employment activities as a custodian. The worker's claim for compensation was denied by Review Office as it was unable to establish that the worker suffered an injury arising out of and in the course of his employment. The worker disagreed with the decision and an appeal was filed with the Appeal Commission. A hearing was held on January 27, 2011 to consider the matter.

Issue

Whether or not the claim is acceptable.

Decision

That the claim is acceptable for left sided carpal tunnel syndrome.

Decision: Unanimous

Background

On April 16, 2009, the worker filed a claim with the WCB for left wrist and hand difficulties that he related to his job duties as a head custodian. The worker indicated that he first noticed symptoms in early 2007 which felt like sharp little pains in his left wrist. In 2007 he went on WCB benefits for a separate back injury and his left wrist stopped bothering him when he was away from work. When he returned to work in July 2008 the pain gradually started to come back and it got worse over time. The pain became constant. He would feel a sharp pain when he grabbed a broom or garbage bag. He had some swelling off and on. He felt numbness in his left thumb and pain if he twisted or turned his left wrist.

The worker described his job duties as follows:

Grabbing boxes, mopping, twisting my wrists, everything that applies for cleaning. I wipe down walls using a duster, windows, wash windows using a rag and a spray bottle, wash floors using a wet mop, sweep floors using a dry mop. I work with wrenches and screw drivers, fixing things and putting pictures up, turning valves off and on boilers, and equipment. I have to write up notes and also work on computer, typing 61 forms - work orders which is approx 10 - 15 minutes a day, off and on throughout the day…I had pain in my left wrist early 2007 and I went to the dr [doctor's name] and he sent me for tests for CTS in my left wrist and confirmed I had CTS. I am always (sic) both hands to do my work and I try to avoid using my left arm.

Information obtained from the employer was that the worker, on April 13, 2009, completed an employer's accident report indicating that in January/February 2007 he began to experience pain in both wrists. The employer noted that the worker had been employed in the custodial section since October 1986. Between October 1986 to July 2005, the worker worked in the capacity of assistant caretaker and caretaker. On July 2, 2006, the worker became the head caretaker. The duties between the 3 positions were similar with the exception of the supervisory responsibilities assigned to the caretaker and head caretaker positions.

The employer noted that there were a significant number of duties that the worker was expected to perform over a regular 8 hour day. "Despite the volume of work, however, each incumbent has the ability and opportunity to choose and determine what order the various duties will be performed in. In this regard, we would suggest that although both hands/arms are required to be used on a regular basis, the variety of duties and flexibility that exists in being able to determine the order in which the duties can be completed, is such that it is not necessary for custodial staff to perform any of the identified duties for prolonged or substantiated time during a regular shift. As well, we would suggest that there is a sufficient range of heavy to light type duties assigned to the caretaking position, that no staff member should have to compromise their physical well being by performing repetitive heavy work that would put undue and prolonged stress on any single part of their anatomy. This fact has been substantiated by the W.C.B. on numerous occasions in the past through review of the job description and work site assessments conducted for the purpose of implementing Modified Return To Work Programs for custodial claimants…Given that [the worker] was absent from work for close to 11 months between the period September 4, 2007 to July 22, 2008 and upon his return to work on July 23, 2008 has not been required to perform heavy/strenuous work due to being accommodated with modified duties, the [employer] is somewhat at a loss as to what work related activities are causing [the worker's] symptoms."

Medical reports showed that on April 15, 2009, a plastic surgeon diagnosed the worker with left sided carpal tunnel syndrome ("CTS") and de Quervain's Syndrome. On April 24, 2009, a different physician reported that the worker had a painful left wrist since 2007 and that he was awaiting hand surgery.

On May 7, 2009, the worker advised a WCB adjudicator that he had CTS in his right wrist but it was not as bad as his left. The worker is right hand dominant. The worker indicated there were no changes to his work duties or increase in workload to account for the onset of his symptoms. The worker advised that he returned to modified duties after his back injury with restrictions to avoid lifting in excess of 10 pounds and to avoid repetitive twisting and turning in his low back. The worker indicated he was 6 feet tall and weighed 195 pounds. He smoked a half package per day for the last 30 + years and drank 2 to 3 cups of coffee per day.

On June 4, 2009, the treating physician reported that the worker had CTS in both wrists, the right being worse than the left hand.

On June 11, 2009, the employer's representative advised the WCB that because of the worker's permanent restrictions related to his separate back injury, the worker had to minimize mopping and sweeping as these jobs involved bending and twisting. As part of the accommodation for the permanent restrictions, the night person was put on notice to be called in on a moment's notice if the worker needed assistance. The only duties that could be considered repetitive in nature could be the sweeping and mopping. Mopping was more prevalent in the winter. Hand mopping involved only spot-mopping. The custodian would use the auto scrubber for large areas. The employer questioned how the worker's claim for left wrist problems could be work related if the worker had been following the permanent restrictions in place for his back.

In a decision dated July 3, 2009, primary adjudication confirmed to the worker that his claim for compensation was not acceptable. The adjudicator stated: "…although the amount of mopping and sweeping you are restricted to performing as a result of your permanent back restrictions may be considered repetitious for only brief periods at a time, there is no evidence that you were exposed to high force repetitive activity involving motions of the wrist such as twisting, gripping, pulling, pinch pressure or repetitive wrist flexion/extension which would expose you to significant work related factors resulting in the development of carpal tunnel syndrome. Based on information concerning your assigned work based on permanent restrictions for your back, there is no evidence to indicate you were involved in work duties that would be considered causal to the development of CTS."

In a report dated July 15, 2009, the treating physician reported that the worker complained of a painful left hand on July 12, 2007. He also had pins and needles of the left hand with complaints of muscle weakness of the left hand. The worker had positive Tinel and Phalen signs, and nerve conduction studies were requested. At this stage, the worker also was suffering from disc disease of the lumbar spine which was his major problem. The physician reported that the worker did not suffer from any wrist difficulties prior to July 12, 2007. The worker next complained of tingling in his hands on July 17, 2008.

A nerve conduction study report dated July 31, 2007 was summarized as follows:

Distal latency of median motor and sensory responses was mildly delayed bilaterally which suggests bilateral median neuropathy at or distal to the wrists (e.g. CTS).

Following review of the new information from the treating physician, the worker was advised on July 17, 2009, that the WCB was still unable to relate his wrist symptoms to his work activities.

In a report to the WCB dated September 30, 2009, the plastic surgeon noted that the worker underwent corrective surgery on August 24, 2009 (left carpal tunnel release and release of left wrist de Quervain's). He stated: "It is difficult to know what role the workplace has on the development of carpal tunnel syndrome. However, it is unlikely that [the worker] uses his hand at home as much as he would at work for eight hours per day. He has no medical conditions that would increase the risk of carpal tunnel syndrome, nor does he have any hobbies that would cause such a condition to develop. I am unaware of any previous fractures of the wrist. With other causes of carpal tunnel syndrome being ruled out, one is left with work as the most likely cause."

In a decision dated October 21, 2009, the adjudicator advised the worker that the September 30, 2009 report did not provide any new medical evidence to support that his condition was directly related to his work activities.

In a submission to Review Office dated December 7, 2009, a worker advisor submitted that the evidence supported that the worker developed an injury after undertaking twenty-two years of job demands with repetitive arm and hand motions. In the event that Review Office did not find a sufficient relationship between the worker's activities and the development of his hand difficulties, it was suggested that his job demands caused an aggravation and/or enhancement of an undiagnosed pre-existing condition which would be compensable pursuant to the WCB's policy on pre-existing conditions.

On February 4, 2010, Review Office determined that the worker's claim was not acceptable as it was unable to find evidence to support that the worker sustained an accident as defined by subsection 1(1) of the Act. In making its decision, Review Office made reference to medical evidence on file to support that the worker's CTS predated his return to work in July 2008. It noted that the worker had risk factors associated with the diagnosis of CTS. The worker's job description and the fact that he was right hand dominant did not support that the worker's bilateral CTS was work related. The job duties performed by the worker were varied and were not continuous in nature.

Review Office further indicated that as it could not establish that an accident had occurred, it did not find that the WCB's policy related to pre-existing conditions applied with respect to the worker's claim for bilateral CTS.

In a decision dated April 1, 2010, the WCB adjudicator advised the worker that: "…there is no evidence that you were participating (sic) any work activities that would be considered conducive to the development of de Quervain's. As such, the claim is not accepted for a diagnosis of de Quervain's."

On May 10, 2010, the worker appealed Review Office's decision dated February 4, 2010 to the Appeal Commission and a 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 arose out of and in the course of his employment.

Worker’s position

The worker was represented by a union representative at the hearing. The position advanced on behalf of the worker was that the carpal tunnel syndrome diagnosed in both of the worker's wrists was caused by repetitive movements in the workplace. The condition was worse on the left side. The worker reported the injury to his employer on April 13, 2009, but first noticed having the problems as early as December 2007. Although the worker was performing modified duties due to a back injury, it was submitted that there was a limit to how much duties could be modified. The work remained repetitive and required hand movement, intense gripping and twisting. The worker would, in fact, overcompensate and rely more on his arms, wrists and hands to accommodate the restrictions related to his back. It was submitted that were it not for the injury created at work, the worker would have been able to attend work on a regular basis.

It was also submitted on behalf of the worker that he ought to have an acceptable claim for de Quervain's Syndrome. As the primary adjudicative decision of April 1, 2010 denying the worker's de Quervain's claim has not been the subject of a reconsideration by Review Office, the worker was informed that the panel did not have the jurisdiction to consider this claim.

Employer’s Position

A representative from the employer was present at the hearing. It was submitted that the medical information on file disclosed that the worker first complained of symptoms in his left wrist during a doctor's appointment on July 12, 2007, then did not complain again until July 17, 2008. During the 11 month period from September 4, 2007 to July 21, 2008, the worker was off work due to a back condition. It was submitted that if the worker's job duties were the primary cause of his CTS, the symptoms would have subsided during the 11 month absence. In fact, they did not and from this one could only conclude that there were other factors at play other than the performance of custodial duties that were causing the symptoms. It was also submitted that after returning to work in July 2008, the worker performed modified duties, which consisted of sedentary work from July 22 to September 1, 2008. Even after the worker resumed modified custodial type duties, there was flexibility and variety in the duties and none would be considered to be highly forceful and repetitive in nature. Overall, it was submitted that there was not sufficient cause for the Appeal Commission to overturn the WCB's decision in this case.

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 CTS was causally related to his work duties. With respect to the worker's claim for CTS in his left wrist, we are able to find a causal connection.

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 a causal relationship to his CTS.

At the hearing, the worker gave evidence regarding the duties he performed as a custodian. He had originally been hired by the accident employer in 1986, but had been at his location since 2005. When he commenced work at this location, he had no problems with either of his wrists. When asked about the duties which he felt contributed to his CTS the worker identified the following:

  • Mopping floors, particularly when he returned to work after his back injury. In order to protect his back and avoid twisting, the worker used more arm and hand motions. After snowfall, the halls would tend to get slushier and the worker would spend about a half hour to 45 minutes mopping in the morning, after school began, then again after lunch, and after each recess. He would also have to mop up any spills.
  • Using an auto-machine to wash the floors (only occasionally).
  • Using a buffer/stripper on the floors, waxing, washing walls (during summer clean up).
  • Turning valves on the boilers (took a couple of minutes once per day).
  • Sweeping stairs and front entrances (ten minutes per day).
  • Repairs and fixing anything which needed attention.
  • Wiping glass and windows (every two days).
  • Shovelling or using a snowblower (when required).

After considering the nature of the work duties performed, the panel is not convinced that the duties the worker performed prior to his absence from work on account of a back injury were causative in the development of the mild bilateral CTS which was detected in the nerve conduction studies of July 31, 2007. In the panel's opinion, the development of this condition was unrelated to his job duties as we are not able to indentify sufficient repetition or loading of the worker's wrists while in a flexed or awkward position which would, in and of itself, tend to cause CTS to develop. The panel also notes that the worker's condition is bilateral, which suggests a non-work related etiology. We therefore find that the worker's bilateral CTS was a pre-existing condition whose etiology was unrelated to activity performed in the workplace.

Although we find that the worker's bilateral CTS was pre-existing and not caused by his work duties, we do find on a balance of probabilities that, with respect to his left side only, the progression pattern of the worker’s pre-existing CTS was accelerated by his work, such that surgery was required. We accept that in the context of a pre-existing condition, the following job duties which the worker performed after his return to work in July 2008 contributed to the worsening of the worker’s condition:

  • Mopping using his arms in a manner to protect his back by placing the right hand at the top of the mop as a pivot and the left hand gripped the handle and moved it side to side. A significant portion of the worker's day was spent mopping floors during the winter of 2008.
  • Operation of the auto machine which required the wrists to be sustained in an extended position with vibration and some degree of force.

It was noted by the WCB that the worker's family physician had recorded that the worker complained of tingling in his hands during a visit on July 12, 2008, which was six days prior to his return to the workplace after an eleven month absence due to his back injury. When asked about this at the hearing, the worker advised that in the months prior to his return to work, he was participating in a physiotherapy program for his back, which he attended three times per week. One of the weight machine exercises he was required to perform involved a lateral pull on a weight machine. The worker explained that when he did this exercise, his wrist would be deeply flexed while he pulled on the weight. This was what caused his left hand to tingle at the time and that it would go away after he rested it. He did not experience pain at the time and the tingling only occurred when he performed this exercise while attending physiotherapy. The panel accepts that this maneuver caused a temporary aggravation of the worker's pre-existing CTS and explains the doctor's record of symptoms prior to the worker's return to duties. We view this to be evidence of a continuing pre-existing condition, but do not consider it indicative of a steadily progressing CTS condition which was worsening despite the worker's absence from the workplace. The worker's evidence was that aside from these flare-ups during physiotherapy, he did not have problems with either of his wrists during the time he was away from work.

After the worker returned to work in July 2008, he experienced a steady increase in his left sided CTS symptoms, which caused his rating of the pain to rapidly increase from 6/10 in July, 2008 to 9/10 by April, 2009. In the circumstances, the panel finds that the worker’s left CTS condition was accelerated by his work duties to the point where surgery was required. It is notable that the NCS studies in 2007 showed basically parallel CTS conditions bilaterally, but after the worker returned to the workplace in July 2008, the left side worsened significantly over the next 9 months. The panel finds that this was due to the increased loading on the left side, primarily due to the way the worker modified the way he mopped in an effort to protect his back.

It is therefore the panel’s finding that his left sided CTS was causally related to his work duties, and his claim for left sided CTS is acceptable as an enhancement of a pre-existing condition.

The worker’s appeal is allowed.

Panel Members

L. Choy, Presiding Officer
A. Finkel, Commissioner
P. Walker, Commissioner

Recording Secretary, B. Kosc

L. Choy - Presiding Officer

Signed at Winnipeg this 3rd day of March, 2011

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