Decision #04/24 - Type: Workers Compensation


The worker is appealing the decision made by the Workers Compensation Board ("WCB") that their claims for left and right carpal tunnel syndrome are not acceptable.

A videoconference hearing was held on November 7, 2023 to consider the worker's appeal.


Date of Accident – March 5, 2019 (Left Hand):

Whether or not the claim is acceptable.

Date of Accident – March 5, 2019 (Right Hand):

Whether or not the claim is acceptable.


Date of Accident – March 5, 2019 (Left Hand):

The claim is acceptable.

Date of Accident – March 5, 2019 (Right Hand):

The claim is acceptable.


Date of Accident – March 5, 2019 (Left Hand):

On March 18, 2019, the worker submitted a Worker Incident Report to the WCB reporting an injury to their left hand that occurred at work on March 5, 2019. The worker reported their injury as "CTS" (carpal tunnel syndrome) which they related to their repetitive duties at work. The worker noted soreness in their hand, with burning in their fingers and wrists, which worsened to numbness in their fingers. They advised they sought medical treatment, was told not to perform those duties for approximately a month and was accommodated with modified duties at work. The worker went on to advise those modified duties were causing swelling in their left forearm from their elbow to their fingers.

The WCB received a copy of the report from the worker's appointment with a sports medicine physician on March 6, 2019. The worker reported they had left bicep repair surgery in 2016 and experienced swelling and irritation to their left arm since then. They presented with burning, swelling pain to their left wrist, radiating up to their elbow/bicep area, which had increased over the last three weeks. The worker advised they were constantly using their hands at work, and experienced the burning pain more while at work. Further, the worker advised the sports medicine physician, they had progressive numbness and pain in their left hand and tightness in their forearm, with difficulty getting through the work day. The worker advised they had undergone electrodiagnostic testing in the summer of 2017, which indicated mild carpal and cubital tunnel syndrome. Upon examining the worker, the treating sports medicine physician noted mild swelling in the medial elbow in the area of the surgical scar. The worker had full range of motion in their elbow, no tenderness was noted in the epicondyles and no pain in their elbow with resistive testing. The range of motion was full in their wrist and no tenderness was noted. A positive Tinel's test was noted at the wrist and elbow. A diagnosis of carpal/cubital tunnel syndrome was provided. Repeat electrodiagnostic testing and bracing for at work and use at work was recommended, along with modified duties of no repetitive gripping or grasping with the left hand and no repetitive lifting or carrying with the left hand.

The WCB contacted the worker on March 21, 2019 to discuss the claim. The worker provided the WCB with details of their job duties and advised that for the past few months, they had been noticing their fingers felt numb, with a burning sensation in their left hand. When asked, the worker advised they experienced a "little tweak or something", in their right hand as well, with pain in their right wrist. The worker confirmed they previously had left biceps surgery for a non-compensable injury and advised the employer had provided them with modified duties due to another non-compensable health issue.

Also on March 21, 2019, the employer submitted an Employer Injury Report. On the Report, the employer noted the worker had not reported a workplace injury and they were only notified as a result of the worker's treating physician submitting their WCB report. The employer advised they accommodated the worker on March 8, 2019; however, after their shift, the worker chose to apply for disability. In an email dated March 22, 2019, the employer noted their concerns with the worker's claim and provided the WCB with photographs of the worker's area and the equipment used by the worker when performing their job duties.

On April 11, 2019, the WCB received a copy of the July 27, 2017 nerve conduction study from the worker's treating neurologist. The neurologist opined the worker had "Mild left CTS" and "Mild left ulnar neuropathy at the elbow." A follow-up report from the neurologist was received on April 25, 2019. The treating neurologist noted the results of the previous examination and after examining the worker, provided "Exam shows slightly decreased sensation in a median nerve distribution on the left and normal on the right. Strength in the hands is intact. Tinel's is positive over the left median nerve at the wrist and negative at both elbows and the right wrist." It was opined the nerve conduction studies showed mild left carpal tunnel syndrome, not changed from the testing in 2017 and mild right carpal tunnel syndrome, with mild left ulnar neuropathy.

The WCB advised the worker on May 15, 2019, their claim was not acceptable. The worker was advised the WCB noted the nature of their job duties were repetitive; however, those duties were not noted to be forceful enough to produce symptoms of carpal tunnel syndrome. Further, it was noted the onset of their symptoms occurred after a non-compensable surgery to their left bicep in 2016.

The worker requested reconsideration of the WCB's decision to deny their claim from Review Office on June 18, 2019, noting their treating healthcare providers supported their left hand difficulties and carpal tunnel syndrome were related to their job duties and not their previous bicep surgery. On July 31, 2019, the employer provided a submission in support of the WCB's decision, a copy of which was provided to the worker. The worker provided a response to the submission on August 7, 2019. A letter in support of the worker's reconsideration request by their treating sports medicine physician was received by Review Office on August 14, 2019.

Review Office was unable to establish a relationship between the worker's job duties and their development of carpal tunnel syndrome on August 19, 2019 and upheld the WCB's decision the worker's claim was not acceptable. Review Office noted some of the worker's job duties were repetitive but were also varied; however, "…were not consistent with the occupational risk factors associated with the development of CTS."

Date of Accident – March 5, 2019 (Right Hand):

In a discussion with the WCB on October 11, 2019, the worker indicated they would like to pursue a claim for an injury to their right hand that also occurred at work on March 5, 2019. They stated the information gathered for their WCB claim for their left hand also included information for their right hand. The WCB directed the worker to file a new WCB claim for their right hand and at that time, the relevant information from the WCB claim for their left hand would be copied to their new claim. On November 28, 2019, the worker filed a Worker Incident Report with the WCB reporting their left hand injury that occurred on March 5, 2019 and noting they had CTS (carpal tunnel syndrome). The worker described soreness in their hand, with burning in their fingers and wrists, and numbness in their fingers that had started in the previous month and a half to two months. The worker noted they wore a brace to sleep and did not take any medications.

On December 4, 2019, the WCB contacted the worker to gather further information regarding their claim. The WCB adjudicator noted from a March 21, 2019 note on the worker’s other claim, the worker reported to the adjudicator at that time, they had not worked any overtime, which the worker clarified to their current adjudicator they did occasionally work some overtime. The worker provided the WCB with a detailed description of their job duties and clarified that a piece of equipment they used had broken and they were required to manually perform that job duty by hand for a period of time. The worker noted they had undergone a nerve conduction study on April 24, 2019 which indicated they had mild bilateral CTS, and at that time, their left hand had worse symptoms than their right hand and they were still able to use that hand. The worker further noted their right hand symptoms had progressed the same way as their left hand and they had undergone CTS surgery on their left hand on December 2, 2019. The worker also noted they had been collecting benefits from their employer’s disability insurer since March 2019 as the employer did not have one handed duties available for them.

The WCB advised the worker on December 5, 2019, their claim was not acceptable. It was noted that while the worker’s job duties were repetitive, the evidence did not support those duties involved “…continuous full flexion and extension…” of their wrists and as such, the force required to develop CTS symptoms was not present. The worker requested reconsideration of the WCB’s decision to Review Office on January 30, 2020. Review Office determined on March 31, 2020, the worker’s claim was not acceptable. Review Office found the worker had not reported difficulties with the right hand during their WCB claim with their left hand. Review Office further found the evidence supported the worker’s job duties were varied and not consistent with the development of CTS and as such, a causal relationship between the worker’s current right hand difficulties and their job duties could not be established.

Both Claims

On July 18, 2023, the worker filed an appeal with the Appeal Commission for their left hand WCB claim. In a discussion with the Appeal Commission on July 19, 2023, the worker confirmed they wanted to proceed with appeals for both their claims and a hearing was arranged.


Applicable Legislation and Policy

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

Subsection 4(1) of the Act provides that where a worker is injured in an accident, the worker is entitled to wage loss benefits for the loss of earning capacity resulting from the accident.

Subsection 39(2) of the Act provides that the WCB will pay for wage loss benefits until such time as the worker’s loss of earning capacity ends, or the worker attains the age of 65 years.

The term “accident” is defined in Subsection 1(1) of the Act and provides as follows:

“accident” means 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) even 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 44.05, Arising Out of and in the Course of Employment, provides some further explanation of the meaning of the term ‘accident.’ Policy 44.05 states in part as follows:

Generally, an injury or illness is said to have ‘arisen out of employment’ if the activity giving rise to it is causally connected to the employment – that is, if it is caused by some hazard which results from the nature, conditions or obligations of the employment. To have occurred “in the course of employment,” an injury or illness must have occurred within the time of employment at a location where the worker may reasonably be, and while performing work duties or an activity incidental to employment.

In other words, an accident will have arisen out of employment if there is a causal connection between the activity that caused the injury and employment and it will be considered to have occurred in the course of employment if the injury occurred during working hours at the place of employment and while the worker was involved in activities incidental to employment.

WCB Policy, Pre-Existing Conditions (the “Pre-Existing Conditions Policy”) addresses the issue of pre-existing conditions when administering benefits. The Pre-Existing Conditions Policy states in part:

Many workers who experience a workplace injury also have a pre-existing condition. The fact that the worker has a pre-existing condition does not disentitle them to compensation for their workplace injury. However, the workers compensation system is designed to compensate workers for workplace injuries, not all injuries. It is often necessary, therefore, to distinguish between a worker's pre-existing condition and their workplace injuries.

The Pre-Existing Conditions Policy further provides:

A pre-existing condition is any medical condition the worker had prior to their workplace injury. Pre-existing conditions may contribute to the severity of a workplace injury or significantly prolong a worker's recovery. Workplace injuries can also have an effect on pre-existing conditions. When a worker’s pre-existing condition is temporarily worsened because of a workplace injury, this is considered an aggravation of a pre-existing condition. When a worker’s condition is permanently worsened because of a workplace injury, this is considered an enhancement of the pre-existing condition. 

Worker's Position:

The worker represented themself at the hearing. It was the worker’s position that the employment as an assembler led to the worker’s left and right arm difficulties.

The worker reported that they had been in their current position since 2016. The position involved wiring harnesses and circuits for each harness daily. At the hearing, the worker described in detail the nature of the work, which includes pulling bundles of wires apart with their hands using a pulling and pushing motion. After the wires have been separated, the worker crimps the wires using a terminating machine for smaller bundles and a manual crimper for the bigger wires. On average, the worker says there are about 200 wires per harness that need to be terminated daily.

The worker said that they noticed increasing pain, swelling and numbness in their hands and wrists and noticed their hands “getting sorer and sorer.” Although the worker’s right hand problems were not as severe as their left hand problems, the worker observed pain and difficulties in both hands. After being off work for a period, the worker noticed that the symptoms improved but would worsen as soon as the worker returned to regular duties. Although the worker acknowledged a previous left bicep repair in 2016 that resulted in some swelling and irritation to their left arm following the surgery, including mild CTS, it was the worker’s position that their current issues with CTS in both the left and right hands were unrelated to the prior surgery given the direct correlation between time at work and the experience of increasing symptoms. Further, their specialist had provided an opinion that the bilateral CTS was related to their work duties and the physical demands of their employment and not the previous bicep repair surgery. The worker therefore submitted that the claim should be accepted.

Employer’s Position:

The employer was represented by the office manager. It was the employer’s position that the worker’s job duties did not cause the worker’s bilateral CTS and, as such, the Review Office decision should be upheld.

The employer’s representative submitted that although the worker’s duties involved some repetitive activity, the duties were nevertheless varied throughout the day and did not meet the parameters of the type of activity that typically resulted in CTS. The accepted work-related factors include forceful and repetitive hand motions, awkward positions, mechanical stress at the base of the thumb, and vibration. The duties do not involve full flexion or extension of the worker’s wrists nor the required force to produce symptoms of CTS. Further, the worker did not initially report the injury as a workplace injury and no specific workplace incident had been identified. The worker also had a verified pre-existing condition, namely a surgical procedure on their left bicep, that could have contributed to their current symptoms. It was therefore the employer’s position that it was more likely than not that the worker’s CTS did not occur out of their employment as a production worker and was not an accident arising out of the course of employment. The Review Office’s decision should therefore be upheld.


The issue on appeal is whether the claim is acceptable. For the worker’s appeal to be acceptable, the panel must find, on a balance of probabilities, that the worker’s right and left CTS arose out of and in the course of his employment. The panel was able to make that finding.

CTS is generally considered to have a number of causes. Some of the most commonly accepted occupational factors associated with CTS include: wrist injury, frequent use of vibrating hand tools, and repetitive or forceful motion with the wrist bent, particularly when done for prolonged periods. Typically, CTS is found in cases where the job duties involve high force or high repetition. There are also several non-occupational risk factors for the development of CTS which include, among other things, age, arthritis, diabetes, hypothyroidism, smoking, weight, caffeine intake, prior wrist injuries, and the bone structure of the wrist itself. Where the CTS is bilateral, it is more often associated with systemic or non-work related factors. It can, however, be found to be related to work where the evidence shows that both hands and wrists were exposed to the types of occupational hazards that could lead to the development of CTS in both hands.

During the hearing, the panel carefully reviewed with the worker the nature of their employment duties and had them describe the duties in detail. The worker’s description of their duties included repetitive activities that involved intricate hand movements and manipulation of wires with a mechanical electric crimper as well as a manual crimper. The worker used both of their hands to separate the wires and to crimp them. For two weeks prior to the reported claim, the mechanical crimper was out of use and the worker was required to complete all crimping using a manual crimper. Although the worker did have complaints from 2017 of mild CTS, the CTS grew worse in 2019, particularly when at work. When off work, the worker’s symptoms improved. Nerve conduction study performed on April 24, 2019 indicated that the worker had mild bilateral CTS, now present in the right hand and unchanged in the left from 2017 testing. The medical report from the worker’s treating specialist also specifically noted that the prior left sided biceps injury and surgery had no bearing on the worker’s bilateral CTS and concluded that: “There is no other cause which explains this diagnosis. He is suffering from a carpal tunnel syndrome which relates to his work duties.”

After carefully considering the evidence before us, the panel is satisfied that on a balance of probabilities, the worker’s duties enhanced the worker’s bilateral CTS. This is supported by the medical evidence on file, the worker’s description of their duties, and the worker’s evidence that the symptoms had previously subsided when the worker was away from their work duties but did not subside after the accident date. This conclusion also takes into account the panel’s understanding that bilateral CTS is generally considered to be idiopathic. However, in this particular instance, given the intricate and repetitive movements of both hands required by the worker to perform their work tasks, the panel is satisfied that those duties would have contributed to the worsening of the bilateral CTS that ultimately required surgeries on both hands.

The panel therefore finds that the worker’s claim is acceptable and the worker’s appeal is allowed.

Panel Members

K. Wittman, Presiding Officer
J. Peterson, Commissioner
M. Kernaghan, Commissioner

Recording Secretary, J. Lee

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

Signed at Winnipeg this 5th day of January, 2024