Decision #42/10 - Type: Workers Compensation
Preamble
The worker filed a claim with the Workers Compensation Board (“WCB”) for bilateral carpal tunnel syndrome (“CTS”) which she related to her work duties as an office manager. The claim for compensation was denied by primary adjudication and Review Office as both were unable to relate the worker’s bilateral CTS condition to her job duties. The worker disagreed and filed an appeal with the Appeal Commission. A hearing was held on March 31, 2010 to consider the matter.Issue
Whether or not the claim is acceptable.Decision
That the claim is acceptable for the left hand only.Decision: Unanimous
Background
On September 30, 2008, a bilateral nerve conduction study was conducted of the worker's wrists and hands. The study identified:
bilateral median focal neuropathy at the wrist of this patient (Carpal Tunnel Syndrome or CTS) that in terms of both sensory and motor criteria is bilaterally of moderate degree, greater on the left than the right in terms of motor criteria, and greater on the right than the left in terms of sensory criteria, with associated bilateral mild chronic denervation of the APB that is of slighter greater prominence on the right, but is associated with slightly greater reduction of recruitment indicating either loss of motor units, or distal conduction block, or both, on the left.
On March 25, 2009, the worker filed a claim with the WCB for tingling and freezing in both thumbs and hands that she related to her work duties which involved typing, bookkeeping, calculating and computer work.
In a consultation report dated March 31, 2009, the treating physician reported that the worker was employed as a bookkeeper for 24 years. She presented with pain in both wrists and tingling and numbness in the last three fingers bilaterally. The examination revealed no swelling on the wrists and the thenar muscles looked atrophied bilaterally. Tinel and Phalen signs were negative and range of movement in both wrists and all fingers were normal.
On April 9, 2009, a WCB adjudicator spoke with the worker. The following information was noted:
· the worker worked full time, 40 hours per week and is right hand dominant.
· the worker started having problems with her hands about one year ago. She tried chiropractic treatment last spring for severe pain and tingling in her thumbs. The treatment helped for a couple of months but then all her fingertips started to go numb and tingle. Some of her co-workers were aware of her ongoing hand difficulties but it was only mentioned verbally.
· her job duties entailed receptionist activities, typing, bookkeeper, computer work and not much phone work. She used a keyboard and a calculator while bookkeeping. She manually sorted bills and receipts. She used her right hand when using the mouse and her left hand when using the calculator.
· the worker indicated that there were no increases in workload. The keyboard she used was adjustable and she had a pad/support for her mouse. She did not have arm rests on her chair but she preferred it that way as she moved around a lot throughout the day.
On April 29, 2009, the WCB determined that it was unable to accept responsibility for the worker's claim. In terms of factors related to CTS, the adjudicator suggested that:
There is considerable debate in medical literature as to what work factors may cause CTS. Occupational factors most commonly reported to be associated with CTS include forceful and repetitive hand motions, awkward positions, mechanical stress at the base of the palm and vibration.
It is generally conceded that the greatest frequency of occupationally-related CTS is found where job duties involved high force and high repetition.
In the adjudicator's view, the worker’s duties as an office manager were not causal to the development of her bilateral CTS condition. The adjudicator suggested that the worker had indicated no recent changes in her work activities. The adjudicator concluded that the employment activities were not highly repetitive and did not require high repetition involving full flexion and extension. While noting that some force was involved, the adjudicator suggested that it was not done in a highly repetitious fashion. The adjudicator noted that the worker performed a variety of duties throughout the course of the day and accepted that certain aspects of her job duties would make CTS more symptomatic. However, in the adjudicator's view, this did not constitute an “aggravation” or “personal injury by an accident” arising out of and in the course of her employment.
On October 20, 2009, the worker appealed the April 29, 2009 decision to Review Office. The worker indicated that she performed large volumes of accounts payable and receivable and a lot of calculating during her 24 years of employment. The worker noted that she had CTS surgery on her left hand on September 16, 2009 and may have to undergo surgery to her right hand. The worker asked the WCB to cover the costs associated with her reflex massage therapy and physiotherapy treatments.
On October 29, 2009, Review Office determined that the worker’s claim for compensation was not acceptable. Review Office cited the medical literature which indicates that CTS can develop from work-related as well as non-work related risk factors. Work-related factors include jobs which require high force repetitive activity involving movements of the wrist such as twisting, gripping, pulling pinch pressure and wrist flexion and extension. Conversely, non-work-related risk factors include gender, pregnancy, diabetes, menopause, hypothyroidism, arthritis, skeletal injury to the wrist, age, smoking, obesity and idiopathic or unknown roots.
Review Office suggested that the worker’s job duties did not involve the repetitive anatomical movements or forces required to result in the development of CTS.
The Oral Hearing
On January 4, 2010, the worker appealed Review Office’s decision to the Appeal Commission and an oral hearing was arranged. The oral hearing took place on March 31, 2010. The panel heard evidence relating to the onset of the worker's CTS, changes in her work demands and a discussion of potential non-work-related risk factors. There was an extensive discussion of the specific nature of the worker's job duties as they related to both her left and right hand.
The worker began by noting she had worked 24 years for the same employer and had never had a workers compensation claim. She indicated that she currently served as office manager for her employer with responsibility for accounts payable, accounts receivable and the preparation of monthly financial statements.
a) Onset
From the worker's perspective, the onset of her CTS symptoms was relatively recent. She did not recall experiencing them in 2005. She indicated that she first noted the condition when she woke up at night and discovered “my hand would be just be all freezy”.
She recalled that the freezing started at night “first of all mostly in my left hand”. She noted that shortly after that “. . . all of a sudden it even happened to me at work”.
She indicated that at the time she was first examined by her chiropractor with regard to her CTS symptoms, the issue was mostly on her left side. A subsequent nerve conduction study “confirmed that I did have carpal tunnel in both of my hands, my left hand being more so than my right hand”. The worker suggested that the symptoms might be more related to her left hand because she did a lot of calculating with that hand.
b) Other risk factors
The worker took some time to discuss other non-work-related risk factors. She suggested that her non-work-related activities did not appear to be related to the development of the syndrome. Although not convinced of their relevance, she did identify certain risk factors related to her gender including pregnancy and menopause.
c) Changes in work situation
During the course of the hearing, the worker informed the panel that there had been substantial changes in her organization dating back to 2002. At or about that time, the day program workshop for approximately 100 individuals was merged with the ongoing residence programs managed by the employer.
The worker indicated that her organization has grown rapidly since that time from about 7 residences to 11. Currently, her organization operates 12 residences. In recognition of the growing demands on office administration, an additional administrative person was hired in January 2008.
c) Nature of work duties
During the course of the hearing, an extensive examination of the worker's job duties took place. The worker suggested that during the first two weeks of the month approximately 60 percent of her time, or three days a week, was devoted to accounts payable. Her duties in this area involved the processing and allocation of costs related to approximately 130 different bills a month.
The accounts payable task required considerable manual work both with a calculator and a pen in order to allocate items on a particular bill to particular cost centres for financial reporting purposes. A single invoice might require the disaggregation of the total costs among the 12 different residences and the work shop as well as separate individual GST calculations.
While there might be certain interruptions during the day, the worker indicated that:
when I'm doing the payables and doing all the calculating it can take me a couple of days to work through you know that area of work that I need to be doing …I could be doing it from morning until evening for a couple of days in a row …when I'm doing it, I'm doing quite a bit of it, and I'm doing it for quite a few hours.
In terms of her left hand job duties, the worker indicated that the use of her calculator for the purpose of accounts payable was the most challenging part of her duties. She testified that she used a large desk calculator with a paper roll. The desk calculator had a ridge about an inch high.
When the worker performed the calculations, she braced her left palm on the table with her thumb acting as a holder and facing towards her body. The thumb generally was not on the calculator. She used her fingers to perform the calculations and tended not to move her palm. Her hand stayed on the calculator for much of the time during the days she performed accounts payable.
The worker also provided an extensive description of her right hand duties in terms of mousing, keyboarding and writing. She indicated that a lot of her work using her keyboard involved the use of templates. When typing invoices, the most typing she would do would be to type two or three sentences on a note. Often, the pain associated with her right hand appeared to involve using the mouse.
The worker suggested that she had a dropped keyboard below the height of her table and that her arms remained in a relatively neutral position. Generally, her mouse was located beside her keyboard although she would move it from time to time. In her view, it was a good mouse.
Reasons
Overview
Considering the evidence as a whole and based on a balance of probabilities, the panel finds the worker's claim acceptable in terms of her left hand but not her right hand.
The panel finds that the worker had a pre-existing bilateral CTS condition which the panel finds not to be work related. However, placing heavy reliance on the worker's oral evidence which it sees as persuasive and credible, the panel finds based on a balance of probabilities that the worker's pre-existing left hand condition was enhanced by her job duties.
In particular, the panel relates the enhancement of the worker's pre-existing left hand CTS to her use of her left hand in an odd anatomical position with considerable flexion for an extensive period time while she performed accounts payable calculations. In the panel's view, the volume and flexion associated with this task supports a finding that her left hand condition was worsened by her work and that an injury (namely an enhancement of a pre-existing CTS condition) arose out of and in the course of her employment.
In terms of the worker's right hand and based on a balance of probabilities, the panel has determined that there was not sufficient volume or flexion involved with her duties to conclude that her right hand injury arose out of or in the course of her employment.
Legislation and Policy
Under s. 4(1) of The Workers Compensation Act (the “Act”):
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.
Section 1(1) of the Act defines an accident as
a chance event occasioned by a physical or natural cause; and includes
(a) a willful and intentional act that is not the act of the worker,
(b) any
(i) event arising out of, and in the course of, employment, or
(ii) thing that is done and the doing of which arises out of, and in the course of, employment, and
(c) an occupational disease,
and as a result of which a worker is injured;
WCB Policy 44.20.30.20, Pre-Existing Conditions, provides:
The Workers Compensation Board of Manitoba will not provide benefits for disablement resulting solely from the effects of a worker’s pre-existing condition as a pre-existing condition is not “personal injury by accident arising out of and in the course of employment.” The Workers Compensation Board is only responsible for personal injury as a result of accidents that are determined to be arising out of and in the course of employment.
The policy discusses when workers are eligible for wage loss benefits and provides:
a) Where a worker’s loss of earning capacity is caused in part by a compensable accident and in part by a non compensable pre-existing condition, or the relationship between them, the Workers Compensation Board will accept responsibility for the full injurious result of the accident.
b) Where a worker has:
i. Recovered from the workplace accident to the point that it is no longer contributing, to a material degree, to a loss of earning capacity, and
ii. The pre-existing condition has not been enhanced as a result of an accident arising out of and in the course of employment, and
iii. The pre-existing condition is not a compensable condition, the loss of earning capacity is not the responsibility of the WCB and benefits will not be paid.
The policy provides the following definitions:
Aggravation: The temporary clinical effect of a compensable accident on a pre-existing condition such that the pre-existing condition will eventually return to its pre-accident state unaffected by the compensable accident.
Enhancement: Where a compensable injury permanently and adversely affects a pre-existing condition or makes necessary surgery on a pre-existing condition.
Pre-existing Condition: A condition that existed prior to the compensable injury.
Risk Factors Associated with Carpal Tunnel Syndrome
The debate about whether a specific individual has developed carpal tunnel syndrome through their work or otherwise can be fraught with controversy. The panel finds itself in general agreement with the statement of the adjudicator that:
there is considerable debate in medical literature as to what work factors may cause CTS. Occupational factors most commonly reported to be associated with CTS include forceful and repetitive hand motions, awkward positions, mechanical stress at the base of the palm and vibration.
It is generally conceded that the greatest frequency of occupationally-related CTS is found where job duties involved high force and high repetition.
Similarly, in terms of risk factors, the panel finds itself in general agreement with the statement of Review Office suggesting that CTS can develop from work-related as well as non-work related risk factors. Work-related factors include jobs which require high force repetitive activity involving movements of the wrist such as twisting, gripping, pulling pinch pressure and wrist flexion and extension. Conversely, non-work-related risk factors include gender, pregnancy, diabetes, menopause, hypothyroidism, arthritis, skeletal injury to the wrist, age, smoking, obesity and idiopathic or unknown roots.
Specific Findings
In coming to its determinations, the panel places heavy weight on the worker's oral evidence which it finds to be credible and candid.
The panel finds that:
l the worker had a pre-existing bilateral CTS condition which cannot be related to her job duties. In drawing this conclusion, the panel notes that the worker's description of her job duties both in the preliminary investigation and during her oral evidence suggested that during the course of a month, she performed a variety of different tasks using her hands in a variety of different ways.
The bilateral nature of the worker's condition would seem at odds with the varied nature of the work activity she undertook with each hand. Focusing on her right hand, the panel finds that her work did not involve the repetitive anatomical movements or forces that one would associate with a work-related genesis for carpal tunnel syndrome.
The panel also observes that the onset of CTS symptoms was not at work but at night when the worker woke from sleep. Recognizing that the worker had other non-work- related risks factors related to her gender, prior pregnancy and menopause and that in certain cases, CTS simply has unknown roots, the panel cannot relate the original development of a bilateral CTS condition to her work, and thus finds that the worker had a pre-existing bilateral condition.
· while the worker had a pre-existing CTS condition in both hands, the CTS condition in the worker's left hand was enhanced by her work related activities. In making this determination, the panel notes that for three consecutive days a week for each of the first two weeks of each month, the worker was involved in intensive calculations related to accounts payable that left her left palm and hand in an awkward anatomical position that resulted in considerable flexion for an extended period of time. In the panel's view, based on a balance of probabilities, this awkward extended position for a relatively long duration worsened the pre-existing condition in the worker's left hand.
The panel observes that the worsening symptoms experienced in the left hand in 2008 is relatively close in time to the period in which increased demands on office staff time led to the hiring of additional administrative staff in January of 2008.
Taking into account the nature of the worker's duties involving her left hand, and considering the evidence of an increase in demand for office assistance relating to the growth of the organization, the panel concludes that the worker's pre-existing left CTS condition was enhanced by her work activities;
l the injury to her right hand cannot be attributed to work related activities. In terms of the volume of activities such as typing and mousing, the panel observes that the worker's tasks involved the extensive use of templates and a relatively low volume of continuous activity.
In terms of flexion, the panel notes that the worker appears to have had a workstation that did not raise material ergonomic issues. She had a dropped keyboard and her arms remained in a relatively neutral location. The mouse was generally located beside her keyboard.
It is the panel’s view that there was not sufficient volume or flexion associated with the use of the worker's right hand to accept that her right hand injury was an accident arising out of and in the course of her employment.
Conclusion
Based on a balance of probabilities, the left hand injury was an accident arising out of and in the course of employment. The claim for the left hand CTS is accepted.
Based on a balance of probabilities, the right hand injury was not an accident arising out of and in the course of employment. The claim for the right hand CTS is not accepted.
Panel Members
B. Williams, Presiding OfficerA. Finkel, Commissioner
P. Walker, Commissioner
Recording Secretary, B. Kosc
B. Williams - Presiding Officer
Signed at Winnipeg this 28th day of May, 2010