A hamstring injury occurs when one or more of the muscles at the back of the thigh are strained or torn. This type of injury is common in athletes who participate in sports that require sprinting, jumping, or sudden changes in direction. Symptoms often include pain, swelling, and difficulty walking or bending the knee. Treatment for a hamstring injury typically involves rest, ice, compression, and elevation (RICE). Physical therapy may also be recommended to strengthen the muscles and improve flexibility. Most people recover fully with proper care, but severe injuries can take longer to heal and may require medical intervention.