For an ASTD claim to be accepted by WorkSafeBC, activities performed at work must significantly contribute to the cause.

Activity-related soft tissue disorder (ASTD) is a term used by WorkSafeBC to describe gradual-onset musculoskeletal conditions of the limbs. Unlike specific acute injuries, such as sprained ankles, with objective clinical findings and clear evidence that the accident occurred at work, ASTDs are far more difficult to adjudicate.

The term ASTD covers musculoskeletal conditions that may arise due to the nature of a person’s work; however, it’s important to recognize that many other factors, including genetics, lifestyle, systemic diseases, and aging, can also play a role. For an ASTD claim to be accepted by WorkSafeBC, activities performed at work must significantly contribute to the cause.

Many musculoskeletal conditions that affect the limbs, including tendonopathies, gout, joint instability, and arthritis, may result in increased pain with use of the limb, be it at work or at home. However, work activities may not have significantly contributed to the cause of the underlying condition. For example a worker with rheumatoid arthritis may feel pain from daily activities such as opening a jar or turning a key. Symptoms may be noticed with use, but the underlying cause is the auto-immune rheumatoid arthritis.

Risk factors

WorkSafeBC assesses a multitude of work risk factors for ASTDs, the more common ones being strain across the muscle or tendon (force); stretch applied to the tissue (awkward postures); movements (repetition); and exposure to significant cold or vibration.

Medical literature has not clearly defined the level of risk factors that is harmful. Therefore, using best available epidemiological evidence, WorkSafeBC, in consultation with physicians, physiotherapists, and workplace representatives, developed guidelines for the more common risk factor levels likely to be causal for ASTDs.

WorkSafeBC has modified and specialized the claim management process for gradual-onset soft tissue disorders, and each office has specially trained staff to adjudicate these claims. The aim is to optimize knowledge of workplace risk factors and associated clinical conditions. Medical support accompanies all decisions made on these difficult claims.

How you can help

A clear, precise diagnosis and physical findings such as “shoulder tendonopathy,” “carpal tunnel syndrome,” or “De Quervain’s tenosynovitis” help WorkSafeBC claims officers focus on the injured worker’s job-related movements that stress the particular muscle, tendon, or nerve, and apply the risk factor analysis more accurately. Non-diagnostic, non-specific terms such as “repetitive strain injury,” “arm tendonitis,” and “overuse syndrome” are not useful in establishing causation. The claims officer knows, for example, that shoulder tendons are vulnerable to compression with arm elevation or that the median nerves are vulnerable to increased pressure in the carpal tunnel space.

Tell your patient what to expect

While our claim management process has been improving, adjudication of ASTD claims is still time consuming. It can take weeks, especially if no specific diagnosis is available from the physician. Therefore, you may wish to warn your patient of the time frame, the possible need for a claims officer to assess the injured worker’s job, and the possibility that the claim may not be accepted.

While your patients wait for their claims to be adjudicated, you may want to suggest that they consider alternate duties at work, which may be more therapeutic and less financially disruptive than total rest. Nirshl and Ashman say that maintaining general body conditioning enhances the rehabilitation process.[1] They also point out that relative rest of the injured muscle or tendon, rather than absolute rest, promotes healing. They suggest altering the way work is done by changing the arm movement, reducing the duration or intensity of the task, or altering the equipment used.

Call us

If you require assistance with an ASTD claim, please contact the medical advisor in your nearest WorkSafeBC office.

—J. Robinson, MD
WorkSafeBC Medical Advisor

—Don Graham, MD, CCFP
WorkSafeBC Chief Medical Officer

References

1. Nirshl R, Ashman E. Elbow Tendonopathy: Tennis elbow. Clin Sport Med 22;2003:813-836.