INERTIA: A Therapist's Thoughts

Eccentrics are a type of exercise or more specifically a type of muscle contraction. I use eccentrics in therapy with my patients but have found more people seem to be "aware" of them without a complete understanding of them.

Simply put, an eccentric muscle contraction is when a muscle is generating force while it is lengthening. Conversely, a concentric contraction occurs when the muscle generates force while shortening. For example, with a biceps curl, during the upward movement of the curl the biceps contracts in a concentric fashion and the downward or lowering motion of the curl is eccentric.

Eccentrics are commonly used to help with recovery and rehab of tendinitis and muscle strains. In the case of Achilles tendinitis, one might use eccentric heel raises during the rehab. Eccentric heel raises could be done by doing heel raises on two feet and then lowering back down on one foot which is the eccentric phase of the exercise.