An in vitro study of individual ankle muscle actions on the center of pressure

The objective of this study was to correlate the effects of muscle force on I the movement of the center of pressure (COP) for increased clinical utility of the COP measurement. Five fresh frozen cadaveric specimens were used to apply a 49 N sinusoidal muscle force to isolated or grouped extrinsic ankle muscles, and a constant ankle joint reaction force at different tibial positions. The muscle force and the vertical ground reaction force (GRT) play the role of a mechanical lever system so that the differential COP movement can be interpreted as a moment arm for the vertical GRF. (C) 2002 Elsevier Science B.V. All rights reserved.