a group of congenital nonprogressive conditions characterized by multiple joint contractures (stiff joints) and abnormal muscle development. Symptoms vary greatly in range and severity. In some cases, only a few joints may be affected and the range of motion may be nearly normal. In most cases, the hands, wrists, elbows, shoulders, hips, feet, and knees are affected. In the most severe cases, nearly every joint in the body may be involved, including those of the jaw and back. The joint contractures are often accompanied by muscle weakness, which may further limit movement. The disorder is thought to have a genetic cause in 30% of cases and is also associated with decreased movement in utero, connective tissue disorders, or maternal illness. Treatment focuses on the specific findings in each individual and may include physical therapy, removable splints, exercise, and surgery. Also called arthrogryposis; Guérin–Stern syndrome.