INVERSE DYNAMIC CALCULATION OF 3D ANKLE JOINT KINETICS DURING GAIT: THE INFLUENCE OF CENTER OF PRESSURE DATA
Keywords: center of pressure (CoP), inverse dynamics, joint torque, gait
AbstractThe purpose of this study was to jnvestigate the effect of the errors in the center of pressure (CoP) locations on three-dimensional (3D) ankle joint torque during the stance phase of gait. Kinematic and kinetic data from one healthy male subject (age: 22 yrs, height: 180 cm, body mass: 80 kg) were collected. Changes in ankle joint torque, calculated during inverse dynamics, during the stance phase of walking were obtained using simulated CoP data with up to ± 30 mm shifts in antero-posterior and medio-Iateral directions. Shift of the CoP in the antero-posterior direction caused a change of magnitude of the plantarflexor torque, while the torque pattern was not altered. On the other hand & change of the ankle inversion/eversion torques were greatly influenced by the CoP shifts in the medio-latera'l directions. A shift of ± 10 mm of CoP in the medio-Iateral direction caused a switch in the inversion/eversion torque of ankle joint. These results suggest the importance of accurate CoP determinations in inverse dynamics procedures.
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