A refined view of the determinants of gait

We evaluated the effect of reducing the vertical displacement of the centre of mass (COM) on the six determinants of gait proposed by Saunders, Inman and Eberhart in 30 healthy adults. We compared the estimated reduction in C OM vertical displacement due to the determinants in their compass model wit h the actual reduction of vertical displacement. The maximum height of the COM for the compass gait model occurred earlier than the actual COM maximum height. Different gait functions were determinant in reducing COM vertical displacement. In both cases heel rise was the main determinant (up to 2/3 of total reduction). Pelvic obliquity and single stance knee flexion contri butions were more important when compass gait COM maximum was used while th ey were barely detectable at the actual COM maximum. Ipsi- and contra-later al knee flexion were detrimental to the reduction of COM vertical displacem ents, while pelvic rotation contribution was beneficial and accounted for u p to 10% of the overall COM vertical displacement reduction. Although a red uction of COM vertical displacement may have important energy implications, determining the specific gait parameters associated with this function is fundamental in understanding gait disability. (C) 2001 Elsevier Science B.V . All rights reserved.