A sprain is an injury to a ligament, the tough, fibrous tissue that connects bones to other bone. Ligament injuries involve a stretching or a tearing of this tissue.
A sprain typically occurs when people fall and land on an outstretched arm, slide into base, land on the side of their foot, or twist a knee with the foot planted firmly on the ground. This results in an overstretch or tear of the ligament(s) supporting that joint.
The ankle sprain is one of the most common injuries in professional and recreational sports and activities. Most ankle sprains happen when the foot abruptly turns inward (inversion) or outward (eversion) as an athletes runs, turns, falls, or lands after a jump. One or more of the lateral ligaments are injured.
Signs and Symptoms of Sprains
The usual signs and symptoms of a muscle sprain include pain, swelling, bruising, and the loss of functional ability (the ability to move and use the joint). Sometimes people feel a pop or tear when the injury happens. However, these signs and symptoms can vary in intensity, depending on the severity of the sprain.
A strain is an injury to either a muscle or a tendon, the tissue that connects muscles to bones. Depending on the severity of the injury, a strain may be a simple overstretch of the muscle or tendon, or it can result in a partial or complete tear.
A strain is caused by twisting or pulling a muscle or tendon. Strains can be acute or chronic. An acute strain is caused by trauma or an injury such as a blow to the body; it can also be caused by improperly lifting heavy objects or overstressing the muscles. Chronic strains are usually the result of overuse – prolonged, repetitive movement of the muscles and tendons.
Common types of lower leg strains are hamstring strains and tendonitis (inflammation of a tendon).
Contact sports such as soccer, football, hockey, boxing, and wrestling put people at risk for strains.