A METHOD FOR INVERSE DYNAMIC ANALYSIS USING ACCELEROMETRY

A method was developed to calculate total resultant force and moment o n a body segment, in three dimensions, from accelerometer data. The me thod was applied for an analysis of intersegmental loading at the hip joint during the single support phase of working and running, using fo ur triaxial accelerometers mounted on the upper body. Results were com pared to a conventional analysis using simultaneously recorded kinemat ics and ground reaction forces. The loading patterns obtained by both methods were similar, but the accelerometry method systematically unde restimated the intersegmental force and moment at the hip by about 20% . This could be explained by the inertial and gravitational forces ori ginating from the swing leg which were neglected in the analysis. In a ddition, the accelerometry analysis was not not reliable during the im pact phase of running, when the upper body and accelerometers did not behave as a rigid body. For applications where these limitations are a cceptable, the accelerometry method has the advantage that it does not require a gait laboratory environment and can be used for field studi es with a completely body-mounted recording system. The method does no t require differentiation or integration, and therefore provides the p ossibility of real-time inverse dynamics analysis. Copyright (C) 1996 Elsevier Science Ltd.