Mechanical Characterization of Subrupture Fatigue Damage in Tendons

INTRODUCTION Despite the high prevalence of tendon injuries, the etiology of tendon rupture is poorly understood. Degeneration due to cumulative microtrauma resulting from overuse has been widely discussed as a major contributor to tendon failure. However, existing biomechanical models of fatigue have largely focused on the relationship between the applied stress and the number of cycles to failure (Wang et al, 1995), identifying stiffness loss as an index of damage. The purpose of the present study was to assess alternate parameters as indices of mechanistic, sub-rupture changes that may underlie the tendon fatigue process.