Bones can break or fracture. Most fractures heal over time. If the bone is broken, its ends need to be realigned. The broken bones are then immobilized, often with a plaster cast, so they can start healing themselves. Bones are capable of repairing themselves. Bone remodeling allows bones to adapt by becoming thicker and stronger when subjected to stress.

Basketball and volleyball players have to jump high. During physical activity, the ankle may twist inward as a result of landing unwantedly. This may cause one or more ligaments around the ankle to stretch. Proper rest and an ankle support are often enough to heal damage to the ligaments that help support the ankle joint. If the ligament injury is more severe and the ligaments have been torn, an operation is required.

The hinge joint of the knee can withstand only one kind of back-and-forth movement. When the knee is twisted, there is a risk of damage to the ligaments and the joint. In most cases, knee injuries require a prolonged period of rest, and they often keep the person from exercising for several months.

When lifting heavy loads off the ground, the lifting position must be taken into account. A vertebral disc can slip out of place while you are twisting or turning when trying to lift an object. Due to displacement, the disc can press on the spinal nerves, resulting in a risk of losing leg function.