Sprains occur when a ligament, the tough band of tissue connecting two bones, is stretched or torn. Sprains are caused by a trauma – such as a fall, twist or blow – that knocks a joint out of position and overstretches or ruptures the supporting ligaments.
In a mild sprain, a ligament is stretched, but there is no joint loosening or instability. A moderate sprain is when the ligament is partially torn, producing joint instability and some swelling. In a severe sprain, ligaments tear completely or separate from the bone, interfering with joint function.
Sprains happen most often in the ankle. In fact, sprains and strains account for more than one-third of lower leg injuries treated in U.S. emergency rooms. If ligaments don’t heal correctly, the result can be chronic ankle instability and recurring sprains. Repeated sprains can lead to ankle arthritis, a loose ankle or a tendon injury.
Wrist sprains can be as difficult as fractures to treat. Like fractures, if a serious wrist sprain or ligament tear is not treated properly, it can affect how your wrist functions and cause long-term problems.
Strains are a twist, pull and/or tear of a muscle and/or tendon. Tendons are cords of tissue that connect muscles to bones.
Acute strains result when a muscle or tendon is overstretched or pulled. Chronic strains result from overuse of muscles and tendons through prolonged, repetitive movement. Inadequate rest during intense training can cause a strain.
In a mild strain, the muscle or tendon is stretched or pulled slightly. A moderate strain, in which the muscle or tendon is overstretched and slightly torn, will cause some muscle function to be lost. In severe strains, the muscle or tendon is partially or completely ruptured, significantly limiting movement.
Strains often occur during sports. Athletes who engage in excessive jumping, such as while playing basketball or volleyball, are vulnerable to back strains. Kicking a football, running or leaping to make a basket can cause a hamstring muscle strain. A strain of the hamstring, a major muscle in the back of the thigh, can sideline you for up to six months.
Treatment of both strains and sprains include: