A sprain is a stretched or torn ligament, according to Mayo Clinic, and a strained muscle is a stretched or torn muscle or tendon. Ligaments are the tissue bands that connect bones to each other at joints. Tendons are the bands that connect muscles to bones.
Mayo Clinic states that sprains are common in the ankle, while strains are common in the lower back and thigh areas. Both types of injury cause pain and swelling and limit movement. Sprains are sometimes accompanied by a popping sound at the time of injury and may result in bruising. Strains, on the other hand, may cause muscle spasms in the injured area. Both types of injury may be treated at home if the injury is mild.
The American Academy of Orthopaedic Surgeons maintains that sprains are usually caused by trauma. A fall or a blow near a joint causes the ligament to pull too far leading to a stretch or tear. Strains are typically caused by muscle overuse. Intensive training, repetitive movements, or rigorous stretching or exercise of a rarely used muscle leads to tears in the muscle or tendon area. The AAOS recommends rest, ice, compression and elevation for immediate treatment. Severe strains and sprains require medical evaluation. Treatment plans may include immobilization and physical therapy. In rare cases, surgical repair is necessary.