In general, the most important factor(s) determining the stability of synovial joints is (a) interlocking shapes of the articular surfaces; (b) reinforcing ligaments; (c) ligaments and muscle tone;...

In general, the most important factor(s) determining the stability of synovial joints is (a) interlocking shapes of the articular surfaces; (b) reinforcing ligaments; (c) ligaments and muscle tone; (d) synovial fluid, which acts like glue; (e) the body’s wrapping of skin, which holds the limbs together.