aduction

Aduction, also spelled aduction, is the anatomical term for movement toward the midline of the body. It is the opposite of abduction. In contemporary medical usage, adduction is the preferred term, while aduction remains a historic or regional variant.

Etymology: Aduction derives from the Latin adducere, meaning “to lead toward.” The spelling aduction reflects an older form and is still encountered in some texts and in non-English contexts, but is generally considered archaic in modern anatomy.

Applications: Adduction occurs at many joints. Common examples include adduction of the shoulder or hip (bringing the limb toward the body's midline), adduction of the fingers or toes (moving digits toward the midline of the hand or foot), and adduction of the eyes (convergence toward the nose). Muscular action behind these movements includes the adductor group in the thigh (adductor longus, magnus, and brevis) and shoulder adductors such as pectoralis major and latissimus dorsi, as well as small intrinsic muscles that contribute to digit adduction.

Notes: In clinical and anatomical writing, the term adduction is preferred to avoid ambiguity with abduction. The form aduction is mainly seen in older literature or as a cross-language variant; modern usage generally treats it as synonymous with adduction unless a source specifies otherwise.