A Novel Approach to Compute Muscle Length during Walking using Subject-Specific Musculoskeletal Models

K. Oberhofer, K. Mithraratne, S. Stott, S. Walt, and I. Anderson (New Zealand)


Musculoskeletal modeling, 3D gait analysis, Magnetic res onance imaging, Cerebral palsy


Musculoskeletal (MS) modeling in combination with 3D gait analysis enables estimation of muscle length changes during walking, and has thus become an integrative part in research studies on children with cerebral palsy. To date, a generic model of an adult human man with muscles modeled as line segments has been most frequently used. We present a novel approach to investigate muscle length changes during gait using subject-specific, anatomically based MS models of the lower limbs. Kinematic data from 3D gait analysis is used as input data to determine rigid bone movement. Thereby, a numerical algorithm based on singular value decomposition is implemented in order to compute the best approximation of rigid femur transfor mation matrix from the position data of a cluster of skin markers. Soft-tissue muscle deformation is achieved using a free-form deformation method called host-mesh fitting technique. The proposed modeling approach was tested on two subjects (boys, mean age 9 y 5 m). The resulting muscle length changes of gastrocnemius and soleus during walking conform with previously published data.

Important Links:

Go Back