unctional impairment begins to happen. Along with a change in strength is a change in muscle contractile properties, the peak evoked twitch torque may decline and contractile speed becomes typically slowed in aging humans (Hicks, A. L. & McCartney, N. 1996). The slowing is indicated by prolonged contraction and relaxation times during stimulated contractions. One reason for slowing is thought to be a loss of motor units leading to a loss of type II muscle fibers and a shift toward a slower muscle fiber type. It has been suggested that the slowing of contractile muscle with age can result in a fusion of muscle force at lower motor unit firing rate. Such early ending of force may cause force to be produced at lower frequency of stimulation, this has been speculated to be advantageous during voluntary contraction, resulting in an increase in neural efficiency or a decreased motor drive necessary to produce desired force (Ng, A. V. & Kent-Braun, J. A., 1999).
             The study by Hicks and McCartney (1996) purpose was to compare the isometric contractile characteristics and fatigability in the elbow flexors and ankle dorsi flexors in older males and females to determine the affects of almost two years, twice per week weightlifting training.
             The elbow flexors consist of the biceps brachii, pronator teres (weak flexor), and flexor carpi radialis (synergist); the nerve supply is the median nerve.
             The Biceps brachii is a two-headed fusiform muscle; the bellies unite as it reaches the insertion point, the tendon of the long head helps to stabilize the shoulder joint. The biceps brachii flexes elbow joint and supinates the forearm; these actions usually occur at the same time (ex. When you open a bottle of wine, it turns the corkscrew and pulls the cork).
             The Pronator teres is a two-headed muscle that can be seen in superficial view between the proximal margins of brachioradialis and the flexor carpi radialis. This muscle pronates the fore...