DISPLACEMENT OF THE PELVIS DURING HUMAN WALKING - EXPERIMENTAL-DATA AND MODEL PREDICTIONS

Displacements of the pelvis during treadmill walking were studied in d ependence of walking speed, stride frequency and stride length. Displa cement curves per stride cycle were described by means of harmonic ana lysis. Simple mechanical, or geometrical models of the body's center o f mass (COM) trajectory during walking were used to predict amplitude and timing of pelvic displacements. As predicted by inverted pendulum models, the amplitude of pelvic displacement in vertical direction dep ended on stride length. Anterior-posterior displacements were predicte d by assuming equal maxima of potential and forward kinetic energy of the body. Predictions for left-right displacements were based upon a m odel that assumed a constant stride width and a sinusoidal movement pa ttern. In agreement with this model, the amplitude of pelvic displacem ent in left-right direction depended on stride frequency. The presente d models give insight into mechanical mechanisms which determine the p elvic trajectory during walking. The presented data may be useful in t he clinical evaluation of gait disturbances. (C) 1997 Elsevier Science B.V.