Question 1: How well do we understand MSDs and their burdens?

Musculoskeletal disorders (MSDs) are painful or disabling injuries to the muscles, tendons or nerves in the lower back, shoulders, neck, elbows, wrists or hands. They are aggravated or caused by overexertion and overuse at work.

MSDs have been various defined and in order to receive compensation from the Workplace Safety and Insurance Board, they need to fall into the following categories: sprains, strains, tears; traumatic inflammation of muscles, tendons, ligaments, joints, etc., musculoskeletal system and connective tissue diseases and disorders; dorsopathies; inflammation and irritation of joints, tendons, muscles and connective tissues; osteopathies, chondropathies, acquired deformities; musculoskeletal system and connective tissue diseases and disorders; fibromyalgia, fibrosis, myofasciatis; back pain, hurt back; soreness, pain, hurt; carpal tunnel syndrome; symptoms involving nervous & musculoskeletal systems; multiple symptoms involving the head and neck.

In asking the question, how well do we understand MSDs and their burdens, we need to reflect on what knowledge gaps could be frustrating our prevention efforts. We may choose to use tissue damage, physiological function, clinical examination, pain, functional decrements, or work disability as measures of MSD burden or to define a case. Different choices could misrepresent the burden, risk factors, the effects of treatment, or the workplace interventions.

On the other hand, if we are grouping disorders with very different etiologies under one umbrella (for example, “non-specific low back pain”), it may lead to either focusing on misleading risk factors or inappropriate interventions. For example, for low back pain, we could ask whether the disorder is due to cumulative damage to a structure, a loss of spine stability; or a statistically rare loading outlier in a normally innocuous task. Each of these three different mechanisms of injury could lead down divergent exposure and intervention paths. 

For more information, read the editorial Why have we not solved the MSD problem?, by Dr. Richard Wells.