Motor unit recruitment is the progressive activation of a muscle by successive recruitment of contractile units to accomplish increasing gradations of contractile strength. A motor unit consists of one motor neuron and all of the muscle fibers it contracts. All muscles consist of a number of motor units and the fibers belonging to a motor unit are dispersed and intermingle amongst fibers of other units. The muscle fibers belonging to one motor unit can be spread throughout part, or most of the entire muscle, depending on the number of fibers and size of the muscle...