Hindleg

Hindleg refers to the rear limb of a four-legged animal. It is used for locomotion, weight bearing, and propulsion, and is typically opposite the foreleg or front limb. In veterinary anatomy, hindleg is the standard term; in general usage, hind limb is also common. Humans do not commonly use hindleg in everyday language, preferring hind limb when referring to the leg that bears the body’s weight in upright posture.

Anatomy and basic structure: In mammals, the hindleg comprises the thigh (femur) above the knee (stifle in quadrupeds), the lower leg (tibia and fibula), the ankle (tarsus), and the foot (metatarsals and phalanges). The hip joint connects the pelvis to the femur; the knee joint is termed the stifle in many animals; the ankle joint is known as the hock in several domestic species. The distal limb may include specialized joints such as the fetlock, pastern, and coffin joints in horses. Major muscle groups include hip extensors and flexors, knee (stifle) extensors (quadriceps) and flexors, and the gastrocnemius–soleus complex for ankle plantarflexion. A common tendon of the Achilles (common calcaneal tendon) anchors calf muscles to the calcaneus.

Variation across species: Hindlegs vary with lifestyle. They provide propulsion and support in most mammals; horses rely on powerful hindquarters for speed and stride length; cats have muscular hindlegs optimized for jumping; birds possess hind limbs adapted for walking, perching, or swimming, with skeletal fusion and tendon arrangements that differ from mammals. In humans, the hind limb is specialized for bipedal locomotion and upright posture.

Clinical relevance: Hindleg health affects mobility and performance. Common issues include lameness, hip dysplasia, stifle (knee) problems, tendon injuries, and cartilage wear. Knowledge of hindleg anatomy and conformation informs diagnosis, treatment, and welfare in veterinary and medical contexts.