Decision #64/23 - Type: Workers Compensation


The worker is appealing the decision made by the Workers Compensation Board ("WCB") that their claim is not acceptable. A teleconference hearing was held on February 15, 2023 to consider the worker's appeal.


Whether or not the claim is acceptable.


The claim is not acceptable.


The worker filed a Worker Incident Report with the WCB on December 22, 2021, reporting a repetitive strain injury to both wrists that occurred November 15, 2021. The worker clarified in the Report that this was the date they had carpal tunnel release surgery on their right wrist. The worker described having symptoms in both wrists "years ago" and noted they initiated a claim with the WCB in 2004 that was denied, but that prior to their surgery, they were encouraged to file a new WCB claim. The worker reported symptoms of constant numbness, soreness and achiness in both upper limbs, localized to their wrists and hands and noted they had undergone a nerve conduction study of both hands in 2020, with the results being positive for bilateral moderate carpal tunnel syndrome (“CTS”). The worker advised there was a shift in their symptoms in 2012, prior to which the pain and numbness was manageable and would come and go, and after which, the pain would stay and eventually, not go away at all. The worker further advised they had reported their difficulties to their supervisors and coworkers throughout the years.

The employer provided an Employer's Incident Report to the WCB on December 20, 2021 noting the worker had been employed in various positions from 1999 to 2017 that involved "…constant use of keyboard and mouse at high-level." The report set out that the worker's physician recommended the use of wrist supports "…which provided temporary relief of symptoms" but the difficulties continued and in 2020, the worker was diagnosed with bilateral CTS.

When the WCB contacted the worker on January 4, 2022 to gather further information, the worker confirmed they initially noticed their wrist difficulties in 2004 and filed a WCB claim at that time, which was denied. The worker stated their belief that their job duties were the cause of these difficulties, with years of keyboarding, using a mouse and the phone at the same time. The worker noted that until 2017, their job duties involved using a handheld phone, not a phone headset, and that their left hand was worse than their right due to constantly picking up and dialing the phone with their left hand. The worker further noted those duties were constant and involved 8 or 10 hour shifts. The worker further confirmed their symptoms changed in 2012 with the pain happening more frequently and continuing for longer periods. The worker described their pain as progressive and noted that in 2013, they sought treatment from a chiropractor who specialized in CTS. The WCB advised the worker that it could not establish that their bilateral wrist difficulties arose from repetitive and forceful work duties and as such, the claim would not be accepted, as detailed in a formal decision letter to the worker dated January 6, 2022.

On March 16, 2022, the worker requested Review Office reconsider the WCB's decision, providing reports from their treating healthcare providers. The worker noted that initially their pain and numbness was mild and intermittent, but their family physician advised that those symptoms could increase and become moderate and severe with longer lasting symptoms. The worker provided Review Office with a copy of the June 4, 2020 nerve conduction study which indicated the worker had "Mild to almost moderate impairment of Median conduction across both wrists. The electrodiagnostic criteria for Carpal Tunnel Syndrome were fulfilled bilaterally." The study also indicated the worker had right lateral epicondylitis. An August 20, 2021 consultation report from the treating surgeon noted the worker's complaints of progressive numbness and tingling in the median nerve distribution bilaterally and indicated the nerve conduction study confirmed "…almost moderate carpal tunnel syndrome bilaterally." Right carpal tunnel release surgery took place on November 15, 2021 and a surgical report was also submitted to Review Office. On April 21, 2022, the employer provided a submission in support of the WCB's decision, a copy of which was provided to the worker.

On May 9, 2022, Review Office determined the claim was not acceptable, noting that risk factors for the development of CTS include a combination of force and repetition or a combination of force and awkward posture and that bilateral CTS was often associated with systemic or non-work related causes. Review Office noted the worker attributed their wrist difficulties to their job duties and acknowledged the worker used their hands extensively while performing those duties but could not classify those duties as involving repetitive forceful gripping or repetitive awkward positioning of their hands and wrists. Further, Review Office noted the worker described a change or "shift" in their difficulties in 2012 but there was no evidence of a change in their job duties at that time to account for the worsening of their symptoms. Review Office also found the worker confirmed they had moved to a managerial position in 2017 and their wrist difficulties continued to worsen despite less physically demanding work in their new position. As such, Review Office determined the worker's claim was not acceptable because a causal relationship between the worker's bilateral wrist difficulties and their work could not be established.

The worker's representative filed an appeal with the Appeal Commission. A hearing was arranged for February 15, 2023. Following the hearing, the appeal panel requested additional medical information prior to discussing the case further. The requested information was later received and forwarded to the interested parties for comment. On May 16, 2023, the appeal panel met again to discuss the case and render a final decision on the issue under appeal.


Applicable Legislation and Policy

The Appeal Commission and its panels are bound by the provisions of The Workers Compensation Act (the "Act"), regulations under that Act and the policies established by the WCB's Board of Directors. The provisions of the Act in effect as of the date of the worker’s accident are applicable.

The Act sets out the definition of an accident in s 1(1) as follows:

“accident” means a chance event occasioned by a physical or natural cause; and includes

(a) a wilful 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...

When it is established that a worker has been injured as a result of an accident at work, the worker is entitled to benefits under s 4(1) of the Act.

Worker’s Position

The worker appeared in the hearing with a representative of their union. The union representative made an oral submission on behalf of the worker, and the worker provided testimony through answers to questions posed by the union representative and by members of the appeal panel.

The worker’s position is that as a result of the various repetitive tasks they undertake in the course of their employment over the many years of that employment, they developed bilateral carpal tunnel syndrome. As such, the worker’s claim should be accepted as an injury arising out of and in the course of their employment, and the appeal should be granted.

The worker’s representative outlined the worker’s position that their injury developed as a result of their continuing work duties, noting that the website information submitted to the panel for consideration in advance of the hearing supports the worker’s position that CTS can develop from repetitive hand motions. The worker’s representative outlined that the worker’s job duties required that they work long shifts in an environment of continuous demands and emergency situations where breaks are not commonly available. The representative described the worker’s job demands as continuous and very stressful, working on a keyboard and mouse without breaks.

The worker testified in response to questions posed by panel members that the equipment they used in their job changed over the many years with the employer. They stated that they used headsets for most telephone communication when they first began but also described frequently reaching with their left arm to use a telephone, which they believe was the reason why their left arm CTS was worse than the right arm. The worker provided further information to the panel as to their work duties, noting that when using an older keyboard, their wrists are in a flexed position, with hands elevated above the wrist due to the angle of the keyboard and recalling that the older keyboards required more force to be applied to the keys. The worker indicated they had a sit/stand workstation and that around 2013, they began using a roller mouse. The worker noted that until 2013 when they moved into a new role, they would work five consecutive 10-hour shifts and then have 4-5 days off before returning to work. From 2013 onwards, the worker worked primarily in a less urgent, less stressful environment, but their work still required a great deal of keyboarding.

The worker noted that they have used nighttime wrist braces since approximately 2005 and that sometimes symptoms were worse in the morning if they had a poor sleep. The worker stated that certain activities, such as holding something for too long or driving, could increase their symptoms and cause “an episode.” The worker stated that their symptoms would arise with some activities, “It would just come and go, and dependent on what I was doing, my positioning.”

The worker described to the panel a shift in symptom presentation around 2011-2012 where symptoms would last longer than previously. The worker noted that they sought chiropractic treatment at that time with a chiropractor who specialized in carpel tunnel issues. The chiropractor provided the worker with exercises they could do to alleviate their symptoms. When the worker became unable to manage their symptoms with exercises, they sought further treatment, ultimately resulting in a surgical referral and repair.

In sum, the worker’s position is that their bilateral CTS developed as a result of their repetitive and strenuous work duties which include keyboarding and mousing as well as the use of a manual telephone in an environment of urgent and continuous demands. As such, the worker’s claim should be accepted and the appeal granted.

Employer’s Position

The employer was represented in the hearing by its workers compensation coordinator who made an oral submission on behalf of the employer.

The employer’s position is that the claim is not acceptable because the evidence does not support a finding that the worker’s bilateral CTS arose out of the worker’s job duties, which do not involve or require the degree of high force, high repetition hand motions or awkward postures as are known to increase the risk of developing occupational CTS.

The employer’s representative submitted that occupational CTS is known to develop from forceful and repetitive hand motions, awkward positions, mechanical stress at the base of the palm, or vibration, and noted that the worker’s position and duties are sedentary and involve primarily computer work. The employer’s representative submitted that the medical reporting demonstrates the worker has other non-occupational risk factors for development of CTS, as set out in the website information on CTS relied upon by the worker’s representative. Further, the representative noted that although the worker is right-hand dominant, the initial reporting by the worker indicates their symptoms are worse in their left hand.

The employer’s representative also pointed out to the panel that in the medical reporting submitted to the WCB, the worker's treatment providers do not provide any medical opinion or any comments at all as to a causal relationship between the worker's job duties and the development of their CTS. Rather, the worker’s treatment providers confirm the nature and severity of the worker’s bilateral CTS and the detail of the treatments provided and proposed.

In sum, the employer’s position is that the evidence of the worker's job duties or the manner in which the worker performed those duties do not support a finding that those duties caused or contributed to the worker’s development of bilateral CTS. As such, the evidence does not support the worker sustained an injury arising out of their employment and therefore the panel should find that the claim is not acceptable and dismiss the worker’s appeal.


The issue for the panel to determine is whether the worker’s claim is acceptable. For the worker’s appeal to succeed, the panel would have to determine that the worker was injured as a result of an accident as defined by the Act, arising out of and in the course of their employment. In other words, we must find that there has been an injury caused by an event or duties arising out of and in the course of employment for the claim to be acceptable. The panel was not able to make such a finding, as outlined in the reasons that follow.

The medical reporting in relation to the worker’s claim confirms the diagnosis of bilateral CTS. The June 4, 2020 nerve conduction study findings indicated mild to almost moderate bilateral CTS. The treating surgeon confirmed this diagnosis in their August 20, 2021 report to the referring physician and indicated that the worker intended to proceed with carpal tunnel release surgery, not yet scheduled at that time. A right carpal tunnel release surgery took place on November 15, 2021. There were no complications, as confirmed in the surgical report.

The panel noted that the treating surgeon did not provide any opinion or comment as to causation of the worker’s bilateral condition. In considering the worker’s position that their diagnosis of bilateral CTS is causally related to participation in their employment activities, the panel sought an opinion from the WCB medical advisor as to whether the worker’s job duties as described in the claim file and in the hearing could account for development of the worker’s diagnosis of bilateral CTS.

The WCB’s plastic surgery consultant set out, in a response to the panel dated March 8, 2023, shared with the worker, that they consulted the AMA Guides to the Evaluation of Disease and Injury Causation (2014), an evidence-based review of the medical literature regarding a variety of conditions, including CTS and that the AMA Guides conclude, with respect to CTS:

• That there is very strong evidence that work duties involving a combination of i) force and repetition or ii) force and posture represent risk factors for CTS…; 

• That highly repetitive work alone had “conflicting (insufficient) evidence” to categorize such duties as a risk factor for CTS; 

• That awkward postures alone were considered low risk; and, 

• That there is insufficient evidence to relate keyboard activities as a risk factor for CTS.

The WCB plastic surgery consultant went on to state that the AMA Guides indicate “many of the studies reviewed on CTS use the following definitions:

• High force was defined as more than 4 kilograms of force (per hand); .

• High repetitions was defined as a cycle time of less than 30 seconds or alternatively, more than 50% of the cycle time involved in performing fundamentally the same activity; and 

• Awkward posture was defined as more than 45 degrees of wrist flexion or extension without excessive radial or ulnar deviation.”

Taking these parameters into account, the WCB plastic surgery consultant concluded that the worker’s “…reported job duties of keyboarding, mousing and use of a manual telephone with the left hand, do not appear to have involved the threshold grasp force associated with carpal tunnel syndrome. As such…this review is not able to substantiate that the [worker’s] job duties, including shift duration, could have led to the development of bilateral carpal tunnel syndrome.” The panel accepts and relies upon this opinion, noting that there is no medical opinion in evidence to the contrary.

On the basis of the worker’s testimony as to the nature of their job duties as well as the information the employer provided to the WCB, the panel finds that the evidence does not support a finding that the worker’s various job duties over the years of their employment with the employer involved the required combination of repetitious and forceful gripping, or forceful gripping with awkward wrist postures as are known to increase the risk of development of CTS. While the panel acknowledges that the worker’s job duties involved a variety of wrist and hand movements that included, from time to time, awkward wrist postures, gripping or repetition, there is a lack of evidence that these activities were sufficiently forceful, repetitive or awkward so as to result in the confirmed diagnosis of bilateral CTS.

Considering the totality of evidence before us and on the standard of a balance of probabilities, the panel is unable to find that the worker sustained injury arising out of and in the course of their employment. Therefore, the worker’s claim is not acceptable, and the appeal is denied.

Panel Members

K. Dyck, Presiding Officer
J. MacKay, Commissioner
M. Kernaghan, Commissioner

Recording Secretary, J. Lee

K. Dyck - Presiding Officer
(on behalf of the panel)

Signed at Winnipeg this 30th day of May, 2023