Relations between joint torque, motion, and electromyographic patterns at the human elbow.

Voluntary movements may be considered kinematic actions resulting from the neural control patterns that activate the motoneuron pools. One school of thought proposes that specific features of the intended kinematic trajectory such as the duration of acceleration are used by the central nervous system to plan muscle activation patterns. Our own experience suggests that it is the intended force trajectory that is directed by muscle activation patterns. Although under many circumstances these two approaches lead to indistinguishable behavior patterns, examples of movements that are incompatible with the former but not the latter approach are presented in this manuscript.