manus

Manus is the anatomical term for the hand in humans and other tetrapods. Derived from the Latin word manus meaning “hand,” the term designates the distal portion of the forelimb, distinct from the upper arm (brachium) and forearm (antebrachium). In humans, the manus comprises three major components: the carpus (wrist), the metacarpus (palm), and the digits (fingers). The carpal bones form two rows that connect with the radius and ulna at the radiocarpal joint; the metacarpals provide the palm’s framework; and the phalanges form the fingers, with the thumb (pollex) opposable in humans and other primates.

In zoological usage, manus contrasts with pes, the hind limb or foot in tetrapods. The structure of the manus varies across species; many mammals have five digits, while birds possess a modified manus that contributes to the wing. In primates, the manus is adapted for grasping and manipulation, with variations such as a highly opposable thumb in humans and other species.

Clinically, injuries to the manus include fractures and dislocations of the carpal, metacarpal, or phalangeal bones, as well as conditions like carpal tunnel syndrome, tendonitis, and arcade-related nerve or vascular issues. The study of the manus is foundational across medicine, rehabilitation, anatomy, and evolutionary biology, reflecting both functional diversity and the evolutionary refinement of grasping and manipulation in vertebrates.