Control of ground reaction forces by hindlimb muscles during cat locomotion.

摘要: It has been proposed that biarticular muscles are primarily responsible for the control of direction external forces, as their activation is closely related and highly sensitive to forces. This functional role supported qualitatively by experimental evidence, but never tested quantitatively lack a mathematical/mechanical formulation this theory difficulty measuring individual muscle forces during voluntary movements. The purposes study were: (1) define rules muscular coordination based on forces; (2) develop model cat hindlimb allows calculation magnitude ground reaction (GRFs) produced muscles; (3) test if mono- resultant GRF. We measured GRF, kinematics, selected activations locomotion. Then, were used input compute muscle-induced assume (and possibly force) increased component GRF approximated then was central nervous system (CNS) help During walking, medial gastrocnemius (MG) plantaris (PL) with increasing proximity while soleus (SOL) vastus lateralis (VL) did not. SOL VL most strongly vertical parallel (braking/accelerating) respectively. concluded from these results MG PL functions an anti-gravity muscle, acceleration/deceleration muscle.