The mechanical response of Achilles tendon during different kinds of sports

SUMMARY The present study investigated the mechanical properties of human Achilles tendon (AT) during different forms of human locomotion, by combining biomechanical tests and numerical modelling. A Pedar-X plantar pressure measurement system and Mega multichannel SEMG system were used to measure the dynamic data of a female athlete during hopping and walking. The human Achilles tendon force (ATF) was determined through inverse muscle force calculation. A 3D finite element (FE) model was developed using subject-specified CT images to simulate the deformation of AT during hopping and walking. The stress/strain within the AT during different subphases (e.g. heel strike, midstance, forefoot contact, push off and toe off) was successfully predicted. Results showed that the muscle forces in hopping were much higher than in normal gait. The maximum stress in hopping was three times of that in walking. The tendon stress increased with external load over different subphases and the maximum ATF was found to be in the push-off phase. Copyright q 2008 John Wiley & Sons, Ltd.