Decoupling of the centre of mass (CoM) and centre of pressure (CoP) during gait initiation. Introduction of a new variable

The propulsive forces required for gait initiation are generated by decoupling the centre of pressure (CoP) and centre of mass (CoM). This exploratory trial studies the feasibility of a new variable to quantify the mechanism of decoupling. Two important aspects are introduced 1) the extrapolated centre of mass (XcoM), which takes into account the COM velocity, and 2) the inclination angle between the (X)CoM and CoP, correcting for body height. Data of instrumented gait analysis were obtained from 9 able-bodied (AB) and 5 patients with a transfemoral amputation (TF). Data were collected at a self-selected walking speed (SSWS) and at maximal walking speed (MWS). The results showed that this variable is sensitive to changes in walking velocity and sensitive to pathology.