Figure 8.
Change in endpoint force in response to endpoint displacement with muscle forces determined by intrinsic muscle mechanics, muscle mechanics and autogenic length feedback, and muscle with autogenic and heterogenic length feedback. Contours represent 0.25 N increase in restoring force, and arrows show the A-P and M-L components. Reflex feedback strongly reinforces the restoring force field. Note that arrows are not generally perpendicular to contours, suggesting that restoring paths will not be straight.