Types of Movement in Skeleton Muscles

The muscle contraction produces two possibilities, antagonist (causing opposite motion) or synergy (causing horizontal motion).

Flexion and Extention

The example of synergy is the one that occurs between pronator teres muscle and prenator quadratus that altogether work in forearm pronation. The examples of antagonist muscle are as follows.

a. Extensor muscle-flexor muscle, which is the movement to straighten (extension movement) and to bend (flexion movement) the tricep and bicep motion.

b. Abductor muscle-adductor muscle, which is the movement to stay away (abduction movement) and to come toward to the body (adduction movement) when we stretch hand to side and turn it back to the initial position.

c. Inversor muscle-eversor muscle, which is the movement to tilt the foot sole to the inside (inversion) and to the outside (eversion).

d. Supinator muscle -pronator muscle, which is the movement to lift up (supination motion) and to invert the hand (pronation motion).