Tesio L.,University of Milan |
Tesio L.,Clinical Unit and Research Laboratory of Neuromotor Rehabilitation |
Rota V.,University of Milan |
Rota V.,Clinical Unit and Research Laboratory of Neuromotor Rehabilitation |
And 3 more authors.
Journal of Biomechanics | Year: 2010
Three-dimensional (3D) path of the body centre of mass (CM) over an entire stride was computed from ground reaction forces during walking at constant average speed on a treadmill mounted on 3D force sensors. Data were obtained from 18 healthy adults at speeds ranging from 0.30 to 1.40 m s-1, in 0.1 m s-1 increments. Six subsequent strides were analyzed for each subject and speed (total strides=1296). The test session lasted about 30 min (10 min for walking). The CM path had an upward concave figure-of-eight shape that was highly consistent within and across subjects. Vertical displacement of the CM increased monotonically as a function of walking speed. The forward and particularly lateral displacements of the CM showed a U-shaped relationship to speed. The same held for the total 3D displacement (25.6-16.0 cm, depending on the speed). The results provide normative benchmarks and suggest hypotheses for further physiologic and clinical research. The familiar inverted pendulum model might be expanded to gyroscopic, "spin-and-turn" models. Abnormalities of the 3D path might flag motor impairments and recovery. © 2009 Elsevier Ltd. All rights reserved. Source