Supinasi

Supinasi, or supination in English, is a term used in anatomy and kinesiology to describe a rotational movement in which a part of the body is turned so that its anterior surface faces upward or forward. The word comes from Latin and is used in both the upper and lower limbs, with context determining the exact action.

In the forearm, supination is the rotation that turns the palm to face anteriorly (or upward when the arm is extended). The movement is produced mainly by the supinator muscle and, when the elbow is flexed, by the biceps brachii. The action is opposed by the pronator muscles (pronator teres and pronator quadratus). Normal functional movement allows activities such as turning a doorknob or using a screwdriver. Limitations can arise from fractures or injuries involving the distal radioulnar joint or the radius and ulna.

In the foot, supination refers to a combination of inversion (the sole turns inward), often with plantarflexion and adduction, resulting in a relatively rigid foot during the push-off phase of gait. Supination is the opposite of pronation, which involves eversion and flattening of the arch. Abnormal or excessive supination can be associated with conditions such as high arches and may influence injury risk, including lateral ankle sprains or stress-related problems. Conversely, insufficient supination can contribute to overpronation and related issues.

Clinically, assessment of supination involves observing the ability to rotate the forearm or to evaluate foot mechanics during stance and movement. Treatments, when needed, may include physical therapy, orthotics, or, in some cases, surgical intervention to address underlying structural issues.