The Appeal CommissionThe Workers Compensation Act of Manitoba

Preamble

The employer is appealing the decision made by the Workers Compensation Board ("WCB")that the worker's bilateral carpal tunnel syndrome was related to her jobduties as a lab assistant.  A hearingwas held on July 21, 2015 to consider the employer's appeal.

Issue

Whether or not the claim is acceptable.

Decision

That the claim is not acceptable.

Decision: Unanimous

Background

On November 7, 2012, the worker filed a claim with the WCB for injury to both wrists and hands that she related to certain repetitive job activities that she performed while employed as a lab assistant. The worker advised the WCB that she began to notice symptoms at work in November 2011. "I first noticed a loss of strength in my right hand. Now I have tingling/numbness in my right hand. There is no tingling in my left hand but I have lost strength. I have trigger finger in my left pinky finger. I have severe carpal tunnel in the right hand and not as severe carpal tunnel in the left hand. My left fingers get stiff during the night when I sleep. I get shooting pains into both forearms too sometimes when I move my hands certain ways."

The worker indicated that she attended her family doctor around the beginning of 2012 and that blood tests were taken. The family doctor then referred her to a specialist and on October 17, 2012, the specialist's diagnosis was carpal tunnel in both hands, severe in the right and less severe on the left.

The worker indicated that she reported her hand/wrist condition to her employer on November 7, 2012 as "I did not know what it was at first."

On November 9, 2012, the employer submitted that there was insufficient evidence, on a balance of probabilities, to show that the worker's job duties were of causative significance to her carpal tunnel disability. The employer indicated that carpal tunnel syndrome ("CTS") in the work environment was caused by highly repetitive work, forceful work, a combination of force, repetition and extreme postures, or hand wrist vibration, none of which were present in the worker's job tasks. Included with the submission was a Physical Demands Analysis report for a lab assistant.

On November 21, 2012, the worker spoke with a WCB adjudicator stating that she had been employed in the same position for 27 years. She noted that there was a change in the process about five years ago and since then, it has been the same. The worker described in detail the job duties that she performed at work which she attributed to her hand/wrist condition and the medical treatment that she received.

Medical information on file showed that the worker was diagnosis with bilateral CTS and trigger finger of the left little finger.

On January 14, 2013, the worker was advised that after considering the nature of her job duties, the WCB was unable to accept responsibility for her claim. The adjudicator noted that the worker's job duties were not considered highly repetitive, did not require high repetition involving full flexion and extension. Although there was some force involved, it was not done in a highly repetitious fashion. It was the adjudicator's position that the worker's job duties were not causal for the development of her condition (CTS and trigger finger). The adjudicator commented that although the worker performed a variety of duties throughout the course of the day, it could be accepted that certain aspects of her duties would make CTS more symptomatic, this did not constitute an "aggravation" or "personal injury by an accident arising out of and in the course of your employment."

On September 3, 2013, the worker provided the WCB with further information (i.e. medical, witness statements, pictures of procedures/tasks) to support that her job duties over the years had led to the development of her bilateral CTS condition and trigger finger.

In a second decision dated October 4, 2013, the WCB adjudicator advised the worker that her claim for bilateral CTS was now being accepted and that no responsibility could be accepted for her left trigger finger. After a further review of the worker's job description and medical information on file, the WCB accepted that the worker's job duties were a contributing factor to the development of her bilateral CTS condition and the worker's claim for compensation was accepted for that condition. The WCB did not accept responsibility for the worker's left trigger finger condition. On October 3 and 4, 2013, letters were sent to the worker and the employer to advise them of the WCB's decision.

On October 21, 2013, the employer filed an appeal with Review Office as they disagreed with the WCB's decision to accept the claim for bilateral CTS. On September 8, 2014, the employer's legal representative provided Review Office with a further submission to support its position that "the nature of the worker's employment activities are of insufficient causative significance in producing bi-lateral carpal tunnel syndrome."

Prior to considering the employer's appeal, Review Office sought medical advice from the WCB's healthcare branch as to whether the worker's job duties were repetitive and forceful enough to contribute to the development of bilateral CTS. In a response dated September 17, 2014, the WCB medical advisor stated:

"Studies have shown strong evidence that the combination of forceful and repetitive wrist movements or grip may contribute to the development of CTS. Forceful grip has been defined as over 4 kg. It is difficult to actually measure grip force for most tasks, but a grip of over 4 kg is more than what would be required to just hold an item. Repetitive is defined as at least once every 30 seconds, and at least 20 hours per week.

However, the etiology of CTS is typically multifactoral. Other factors that contribute to its development are age, elevated BMI, female, diabetes, other comorbidities, genetics, etc. Those who are predisposed to the condition due to other factors may have a lower threshold for developing the condition when exposed to less forceful or less repetitious hand movements.

This worker does do some repetitive firm grip and wrist movements throughout her work day. It is noted on the physical demands table to be done frequently (34-66% of a shift). In a typical 40 hour work week, this would equate to 13- 26 hours per week. The repetition of movement would therefore meet the criteria for the development of CTS.

The force involved with a particular task is harder to measure. Average female grip strength in a 50 year old female would be about 25-30 kg. So forceful grip would be about 15% of full grip. Some of the job duties such as massaging units of blood, lifting full cooling trays or green buckets, manipulating tubing, applying clamps, squeezing or massaging product, shaking product, handling product in general, would require firm grip, but whether that equates to 4 kg is difficult to determine..

Based on this review, the worker does work that would meet the criteria for repetitive in terms of the development of CTS. The force of the grasp required has not been sufficiently measured, but due to the nature of the activities, it seems reasonable that it would be considered forceful.

The worker may be predisposed to CTS due to her age and being female, so in that environment it is likely that the job duties are repetitive and forceful enough to contribute to the development of bilateral CTS."

On October 15, 2014, a worker advisor, acting on the worker's behalf, submitted to Review Office that the worker's claim was rightfully accepted by the WCB on the basis that her job duties contributed to the development of her CTS condition. In the event that Review Office found that the onset of the worker's right or left-sided CTS was not related to her work duties, it was submitted that the claim was still acceptable on the basis that continuing to perform her regular work duties for an almost 2 year period beyond the onset of her right sided symptoms likely caused or at least contributed to an acceleration of her condition resulting in the need for right-sided surgery in September of 2013.

On October 16, 2014, Review Office provided the employer's legal representative with a copy of the September 17, 2014 WCB medical opinion and the worker advisor's submission dated October 15, 2014 for comment. Comments by the legal representative to Review Office were later received dated October 17 and November 10, 2014.

In a decision dated November 14, 2014, Review Office referred to specific file evidence to support its position that the worker's bilateral CTS condition was related to her every day job duties which involved repetition and the use of force and therefore her claim for compensable was acceptable. On December 3, 2014, the employer appealed Review Office's decision to the Appeal Commission and a hearing was arranged.

Reasons

ApplicableLegislation and Policy

The employer has appealed the WCB's decision that accepted the worker'sclaim, by relating the onset of the worker's bilateral carpal tunnel syndrome(CTS) condition to her job as a lab technician.

The Appeal Commission and its panels are bound by The WorkersCompensation Act (the “Act”), regulations and policies of the Board ofDirectors.

Sections 1(1) and 4(1) of the Actset out the circumstances under which claims for injuries can be accepted bythe WCB, and state that the worker must have suffered an accident that aroseout of and in the course of his employment. Once such an accident has beenestablished, the worker would then be entitled to the benefits provided under theAct.

WCB Policy 44.10.20.10 Pre-ExistingConditions states that a claim can also be accepted if there was awork-related aggravation or enhancement of a pre-existing condition.

The Employer's Position

The employer was represented by an advocate and its Coordinator,Occupational Health & Safety who was available to assist with technical andoperational information. The Coordinator had also filmed various elements ofthe worker's job duties which had been placed on the WCB file prior to thehearing.

The advocate's position was that the worker's job duties neither caused theworker's bilateral CTS condition nor aggravated nor enhanced an underlying orpre-existing CTS condition. While there are two medical opinions on the filesuggesting that there is a causal relationship, her position is that theworker's doctor did not see or observe the physical demands of the job.Similarly, the WCB medical advisor relied only on the physical demands analysisand photos on the file and did not see the ergonomic assessment of the worker'sjob duties, which was placed on the file in November 2014, at a later date. Aswell, the medical advisor's comments of April 18, 2014 were couched in neutralterms, that "She performed repetitive and prolonged firm grasp at work,which can­ contribute to the development of this condition."[advocate's emphasis]

The advocate described the relevant occupational risk factors of CTS asbeing force, repetition, awkward postures, environmental, and vibration. Sheindicated that contrary to the worker's position, long term accumulation over awork career was not a risk factor for the development of CTS. She asked thepanel to place considerable weight on the physical demands analysis and theergonomic assessment, as they show low risk factors that do not equate to theidentified hazards for the development of CTS. The occupational therapist whoperformed the ergonomic assessment has been doing this type of work for anextended period of time with an established expertise that should be preferredover the worker's opinions as to whether there were work-related causes for herCTS.

The advocate described the worker's job duties as being consistent andsteady, with the worker having the opportunity to change positions at any time.There were 13 different job tasks performed in a day or over the course of theweek, meaning there wasn't any sustained repetitive and frequent activity, andthere were ample micro breaks that allowed the worker to oxygenate her tendonsand recover to her original recovery state. There was task variety, and none ofthe jobs were prolonged or repetitive in a way that would lead to thedevelopment of CTS.

The advocate also asked the panel to review a submitted B.C. WCAT decisionand in particular the findings in respect of the nature of the same job dutiesthat were performed by this worker. In that regard, the panel advised that itwould base its decision on the information that was on file and as presented atthe hearing.

The Worker's Position

The worker was represented by a worker advisor whose position was that herjob duties were sufficient to cause her bilateral CTS condition. In thealternative, the worker may well have a

predisposition to the development of CTS because of her age and gender, butthat even if it was caused by non-occupational factors, she continued to workin her job for two years and her job duties would have aggravated or enhancedher CTS.

The worker provided considerable detail regarding her job duties. Her labdeals with the processing of 130 units per day, divided among six staff whohave various start times. Although there are 13 different job duties/tasks inthe whole process and everyone is cross-trained, some staff tend to specializein certain task areas. As well, there are different start times which willaffect what tasks are done by each staff member. The worker does do differentshifts but most often volunteers for the earliest start, at 6 a.m. As a result,most of her focus is on the earlier job tasks that are performed on theincoming units.

The worker then discussed four of the positions in detail which were themost challenging for her. She had prepared and submitted video to the panelprior to the hearing, which showed her doing those positions:

·        The first task involved bringing several small itemstogether, folding and arranging them into a bundle on a table in front of her,and then packing or stuffing them into a plastic can which would be used on thenext step in the production process. The fit into the can was tight andrequired her to press down with flat palms on the top of the stack of items, topush them all the way down. The worker was standing above the can which was onthe table in front of her and used her body weight to assist in pushing down.The panel confirmed with the worker that there was a bit of extension in herwrists when she pushed the items in.  This task was performed up to 30 times at thebeginning of her shift and would often occupy the first hour of her day withouta break.

·        The second task involved grasping a plasticconnector that needed to be snapped or broken between her thumb and index (andsupporting fingers), by bending it back and forward three times. The employerhad samples of that item and the panel members were given the opportunity totry that operation, under the guidance and instruction of the worker. Theworker's evidence is that she would do that operation on six units at a time.It was done in two stages. She would break two connectors on each unit (for atotal of 12) at a time, then come back soon after, within minutes to break athird connector on each unit (a final total of 18).

·        The third operation was described as"flossing" which involved squeezing the unit and the tube at the topof it with her thumb and finger to remove air. The panel observed that this wasdone mostly with one hand.

·        The fourth operation involved taking the unit (asoft plastic bag with liquid) between her two hands and rub it back and forthsteadily between her palms, in front of her, for a while to mix the contents.In discussion with the parties, the weight of the bag was described variouslyas being in the 500-800g range.

The worker advisor's position that there was sufficient forceful grip,squeezing, repetition and frequency in an extremely busy and fast-paced jobwith time deadlines to cause or exacerbate the worker's bilateral CTScondition.

Analysis:

In order for this employer's appeal to be successful, the panel would haveto find that the worker's bilateral CTS condition was not causally related toher employment. We have carefully reviewed the evidence available in the fileand presented at the hearing, and have concluded on a balance of probabilitiesthat the worker’s job duties would not have resulted in the development of abilateral carpal tunnel syndrome.

The panel was particularly appreciative of the quality of the submissionsmade by both advocates as well as the detailed information on the job dutiesprovided by the worker and the two videos that were provided by the worker andthe employer.

CTS is defined as the impairment of the motor and/or sensory function of themedian nerve as it traverses through the carpal tunnel. CTS is caused by eitherintrinsic swelling of the median nerve, or by extrinsic compression of themedian nerve by one of the many surrounding structures of the wrist.

CTS has a number of causes. Some of the most commonly accepted occupationalfactors associated with CTS include: wrist injury, frequent use of vibratinghand tools, and any repetitive or forceful motion with the wrist bent, particularlywhen done for prolonged periods without rest. Generally, CTS is more commonlyfound where the job duties involve high force and high repetition. BilateralCTS presents another challenge in that it is often associated with systemic ornon-work-related factors, but it can in any event be found to be caused bywork, if the evidence shows that both hands and wrists were exposed to thetypes of occupational hazards that could lead to the development of CTS in eachhand.

To decide this appeal, the panel must consider the worker’s job duties todetermine whether, on a balance of probabilities, those duties might havecaused or contributed to her CTS.

Dealing with the worker’s job duties, the panel had the opportunity tocarefully examine the nature of the worker's job duties. After considering theevidence as a whole, we are unable to find that the work duties either causedor contributed to the worker’s CTS.

On balance, after considering the nature of the work duties performed, thepanel is not persuaded that the worker’s job duties caused her bilateral CTS. Theoverall impression was that the worker's job was fast paced and had a number oftasks that involved the hands and wrists, but that overall the job had far more"busy" work than acute or prolonged activities or sustained force andrepetition that would be causative of CTS in either her right or leftwrist/hands.

The panel did carefully consider the specific work duties proposed as beingthe most problematic for the worker. These are described in detail in theworker's position above:

·        The folding/packing job task: The panel notesthat this was a very busy hour for the worker. The panel finds that thegreatest portion of the task involves the busy work of organizing a number ofmaterials on a table in front of her into a right sized bundle. The task ofpushing the bundle into the can is the most aggressive part of this job task.It takes a few seconds of pushing to get the bundle into the can, but the panelnotes that the worker is using the flat of her palms to push down, with wristsonly in slight extension. While the required force was not measured, the panelnotes that the job was done carefully so that the liquid bag would not puncture,As well, the worker's evidence was that she would sometimes tap-tap-tap the canlightly to finish the insertion of the contents. This suggests to the panelthat the push down force on the palms was at best light to moderate. The panelalso finds that there were rest/recovery cycles between each press, with the interveningactivities of preparing the next set of materials for the next can.

·        The snapping/breaking connector job task: Thepanel had the opportunity to try this task after being "trained" bythe worker (herself a certified trainer in her lab) as to the proper technique.Each snapping requires the connector to be pressed forward and back and forward(three times in all) for it to break. The task does involve more grip pressurethan would have been anticipated to accomplish the task, but it was certainly amanageable task. The panel finds that this type of task does involve the typesof risk factors (forceful grip) that could be associated with the developmentof CTS. It also requires the use of both hands. If this task had been performedrepetitiously and over an extended period of time, the panel would beconsidering this to be a potential cause of the worker's CTS. The evidence,however, is that this job is done infrequently over the course of the day andfor small periods of time. The worker performs this task in batches of 18 (onsix bags). She is self-paced while hanging bags, breaking the 12 connectors,moving on to other tasks, and then returning to the bags within minutes tobreak the other 6 connectors. In between, she is doing other tasks, and then isoff to other job tasks for extended periods of time before coming back to thiswork station to do another 6 bags. Again, the panel cannot find the necessaryforce, repetition and frequency to find that this task would cause CTS orexacerbate an underlying condition.

·        The flossing position: The panel finds thatthere is not the necessary force and repetition in this task. The panel notesthat this job is mostly done with one hand and again, is self-paced by theworker, with other small tasks causing micro breaks between each time theworker flosses. Again, this task is broken up with other job tasks that areperformed over the course of the day. The panel finds that this task does nothave the occupational risk factors associated with the development of bilateralCTS.

·        The rubbing/mixing position: The worker'sevidence is that she provides enough force to the bottom/sides of the bag toensure that it does not fall out of her hands, while she rubs the bag back andforth between her hands. The panel notes that the worker holds her handsdirectly in front of her with her arms extended, with minimal wrist extensionand that the pressure required is not significant and that this job duty wouldnot be a risk factor for CTS.

The panel notes the worker's reliance on the opinion of her doctor and theWCB medical advisor who reviewed the photos on file, as well as the physical demandsanalysis, as the best evidence to support a relationship between her job dutiesand her bilateral CTS condition. However, we note firstly that the medicaladvisor had not seen or commented on the ergonomic assessment which was addedto the worker's WCB file about two months following the medical advisor'sreview, and secondly she expressed some reservations about her opinion,particularly as the grip pressure or force for a number of the tasks had notbeen measured. In contrast, the panel notes that the ergonomic assessment ofall 13 jobs provides a rigorous assessment of the risk factors of all thepositions, and is essentially silent on risk factors (such as repetition,force, grip, frequency, awkward positioning, etc.) to the hands/wrists forthose jobs, with the most significant feature being "negligibleforce" for a number of positions. In the panel's view, the ergonomicassessment mirrors what we were able to observe in the videos and in theevidence and demonstrations provided at the hearing.

Based on the foregoing, the panel is unable to relate, on a balance ofprobabilities, the worker’s bilateral CTS to the work duties which were beingperformed by her as a lab technician. We further find that the worker’sbilateral CTS was not aggravated by her job duties and that the evidence doesnot support an aggravation or enhancement of the condition.

Accordingly, we find that the worker did not suffer awork-related injury that meets the requirements of subsections 1(1) and 4(1) ofthe Act, and her claim is therefore not acceptable.  The employer’s appeal is approved.

Panel Members

A. Scramstad, Presiding Officer
A. Finkel, Commissioner
M. Kernaghan, Commissioner

Recording Secretary, B. Kosc

A. Finkel - Commissioner

Signed at Winnipeg this 30th day of July, 2015