Do Inflammatory Responses to Eccentric Exercise Suggest a Fatigue Failure Process?

Abstract

Recent evidence strongly suggests that force and repetition interact in a consistent manner to affect musculoskeletal disorder (MSD) risk, likely due to an underlying fatigue failure process in affected tissues. This pilot study evaluated whether a force-repetition interaction was present with respect to inflammatory responses of elbow flexor muscles after eccentric exercise. 24 subjects performed eccentric contractions with 6 assigned to each of 4 force and repetition combinations. Dependent measures included MRI data on edema in the muscle (day 2 versus day 0), relaxed elbow flexion angle, and isometric strength (both obtained days 0, 1, 2, 4, and 8 post-exercise). Significant force-repetition interactions were found for relaxed elbow angle at days 2 and 4 post-exercise (p < 0.05), and for days 2 and 4 for isometric strength (p < 0.05).