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　(C)　2008　John　Wiley　&　Sons,　Ltd.