Role of biomechanics in rotator cuff pathology: North American perspective.

The biomechanical properties of, and mechanical environment surrounding, the rotator cuff continue to be a research area of great interest as injury and failure of these tendons are among the most common of shoulder pathologies, with incidence increasing in older populations. Recent literature has refined our knowledge of the anatomy, the role of the various tendons in movement and shoulder stability, and structural and material properties of the human rotator cuff. Furthermore, animal models have characterized the effects of mechanical loading on rotator cuff properties, the biomechanical interactions among cuff tendons in uninjured and deficient rotator cuffs have been described, and more recent imaging studies have provided novel insights into the function of the rotator cuff in vivo. Research to advance our understanding of the biomechanical factors contributing to rotator cuff disease is needed, as the etiology, prognostic indicators, and reasons for treatment failure are poorly understood. We summarize published biomechanical literature on the rotator cuff to provide a current perspective on potential mechanisms involved in cuff pathology.