Effects of foot orthoses on Achilles tendon load in recreational runners.

BACKGROUND: Achilles tendon pathology is a frequently occurring musculoskeletal disorder in runners. Foot orthoses have been shown to reduce the symptoms of pain in runners but their mechanical effects are still not well understood.

METHODS: This study aimed to examine differences in Achilles tendon load when running with and without orthotic intervention. Twelve male runners ran at 4.0 m·s(-1). Ankle joint moments and Achilles tendon forces were compared when running with and without orthotics.

FINDINGS: The results indicate that running with foot orthotics was associated with significant reductions in Achilles tendon load compared to without orthotics.

INTERPRETATION: In addition to providing insight into the mechanical effects of orthotics in runners, the current investigation suggests that via reductions in Achilles tendon load, foot orthoses may serve to reduce the incidence of chronic Achilles tendon pathologies in runners.