Sprains and Strains: What's the Difference?
Sprains and strains are among the most common injuries in sport.
What is a sprain?
A sprain is a stretch and/or tear of a ligament, the fibrous band of connective tissue that joins the end of one bone with another. Ligaments stabilize and support the body's joints. A sprain is caused by direct or indirect trauma (a fall, a blow to the body, etc.) that knocks a joint out of position, and overstretches, and, in severe cases, ruptures the supporting ligaments. Typically, this injury occurs when an individual lands on an outstretched arm; slides into a base; jumps up and lands on the side of the foot; or runs on an uneven surface. While the intensity varies, pain, bruising, swelling, and inflammation are common to all three categories of sprains: mild, moderate, and severe. The individual will usually feel a tear or pop in the joint. A severe sprain produces excruciating pain at the moment of injury, as ligaments tear completely, or separate from the bone. This loosening makes the joint nonfunctional. A moderate sprain partially tears the ligament, producing joint instability, and some swelling. A ligament is stretched in a mild sprain, but there is no joint loosening.
What is a strain?
A strain is an injury of a muscle and/or tendon. Tendons are fibrous cords of tissue that attach muscles to bone. Chronic strains are the result of overuse (prolonged, repetitive movement) of muscles and tendons. Inadequate rest breaks during intensive training precipitates a strain. Acute strains are caused by a direct blow to the body, overstretching, or excessive muscle contraction. Typical indications include pain, muscle spasm, muscle weakness, swelling, inflammation, and cramping. In severe strains, the muscle and/or tendon is partially or completely ruptured, often incapacitating the individual. Some muscle function will be lost with a moderate strain, where the muscle/tendon is overstretched and slightly torn. With a mild strain, the muscle/tendon is stretched or pulled, slightly.