forelegs

Forelegs, or front legs, are the anterior limbs of a quadruped. They bear significant body weight, contribute to propulsion, and can assist with manipulation, grasping, or digging. In many mammals they carry claws, nails, pads, or hooves for traction. In birds and aquatic mammals, the corresponding forelimbs are adapted for flight or swimming and are not typically described as forelegs.

Anatomy: The foreleg typically includes a shoulder girdle (scapula), upper arm (humerus), forearm (radius and ulna), wrist (carpus), and hand or paw (metacarpals and phalanges). The major joints are the shoulder, elbow, and wrist. The arrangement is homologous to the hind limb across tetrapods, with species-specific modifications.

Function and variation: In four-legged animals, forelegs support weight and contribute to gait. They may be specialized for digging, grasping, or climbing, depending on ecology. Horses rely on the forelegs for braking and propulsion, while predators such as cats and dogs use forelegs for locomotion and capturing prey. Some species also use forelegs for manipulation of the environment.

Evolution and terminology: Forelegs are part of the pentadactyl limb, a shared tetrapod blueprint that varies through bone fusion, digit reduction, and joint specialization. In birds the forelimbs are modified as wings; in whales and seals they are flippers. In common usage, front leg describes quadruped forelimbs; birds use wings instead of forelegs.

Clinical notes: In veterinary medicine, foreleg injuries such as radius or ulna fractures, shoulder dislocations, and carpal injuries affect mobility. Lameness assessments frequently focus on forelimb function to diagnose musculoskeletal or soft-tissue problems.