Stretching for prevention of Achilles tendon injuries: a review of the literature.

Professional and recreational athletes commonly perform pre-exercise stretching to prevent musculoskeletal injuries. Little definitive evidence exists that clearly demonstrates the efficacy of stretching in reducing injury. Achilles tendon injuries are among the most common injuries affecting active individuals in the United States today. Clinicians commonly recommend stretching the Achilles tendon without concrete scientific evidence to support such a claim. Few studies have addressed the effect of stretching in Achilles tendon injuries, and it is unclear if the conclusions made for musculoskeletal injuries can be applied to the Achilles tendon. Biomechanical studies of the Achilles tendon and measurements of the tendon's reflex activity have demonstrated possible mechanisms for the potential benefit of stretching, including load-induced hypertrophy and increased tendon tensile strength. Recent prospective studies have contended that reductions in plantarflexor strength and increases in ankle dorsiflexion range of motion from stretching the Achilles tendon may increase the risk of injury. Studies examining stretching in injury prevention, the biomechanical properties of injuries to the Achilles tendon were compiled and reviewed. Although many theories have been published regarding the potential benefits and limitations of stretching, few studies have been able to definitively demonstrate its utility in injury prevention.