Adduktio

Adduktio, or adduction in anatomical terms, is a movement that brings a limb or other body part toward the midline of the body or toward another part. In humans it most commonly refers to movements of the limbs, such as the arm toward the torso or the thigh toward the midline, and it is considered the opposite of abduction, which moves away from the midline. Adduction can occur across various joints and is described relative to the anatomical midline and the plane of movement.

Etymology and scope: The term derives from Latin adductio, from ad- “toward” and ducere “to lead.” Adduction applies to several body regions, including the shoulder, hip, fingers, and toes, with each region involving distinct muscle groups and biomechanics.

Shoulder and upper limb: Adduction of the arm brings the distal segment toward the body. Primary muscles include the pectoralis major and latissimus dorsi with teres major contributing, aided by the anterior fibers of the deltoid in certain movements. In the hand, finger adduction refers to drawing the digits toward the midline, a motion produced by the palmar interossei, while the dorsal interossei mediate abduction.

Hip and thigh: Hip adduction draws the thigh toward the midline. The major muscles are the adductor longus, adductor brevis, adductor magnus, gracilis, and pectineus, with obturator externus contributing in some movements. These muscles are primarily innervated by the obturator nerve, with variations for the pectineus.

Clinical relevance: Adduction strength and control are tested in sports medicine and neuromuscular exams; weakness or pain during resisted adduction can indicate groin injuries, muscle strains, or nerve involvement. Adduction is routinely contrasted with abduction to assess joint function and muscular integrity.