Fig. 5.

Comparison of force and moment fields measured in ‘restrained’ trials, in which all movement at the ankle was constrained, and ‘released’ trials in which rotation about the Z-axis was allowed. (A) Comparison of GRp data collected from animal 3. Gray arrows show the measured force and moment fields in a restrained trial, which is same as data shown in Fig. 3. Black arrows show the measured force and moment fields in a released trial. Note that z-moments in the released trial are close to zero, because the ankle is allowed to rotate around the Z-axis. The other forces–moments were only minimally altered between the two restraint conditions. (B) Comparison of BFp data collected from animal 3. Conventions are the same as in A. Note that the force–moment fields for the BFp were nearly identical for released and restrained trials. That is, although both trials are plotted in each figure, at most positions they are indistinguishable.