Tears or strains to ligaments or tendons occur when abnormal motion causes the fibers that comprise the structure to stretch too far or break. Such injuries produce pain and inflammation at the site of the strain or tear. Other symptoms of torn ligaments or tendons include feelings of numbness and tingling and referred pain (i.e., pain felt at a location other than the injured joint). In some cases, muscle spasms may occur as local muscles attempt to force the joint back into its proper location. Pain or swelling also can impair a person’s ability to walk or bear weight on the affected joint. These types of injuries often occur in collision sports such as football or rugby. Common injuries that fall into this category are a torn medial collateral ligament (MCL), a torn lateral collateral ligament (LCL), a torn anterior cruciate ligament (ACL), a torn posterior cruciate ligament (PCL), torn lateral ankle ligaments, torn acromioclavicular ligaments, torn rotator cuff tendons, and torn Achilles tendons. Some treatments of ligament and tendon tears tend to focus on these spasms, rather than the injury itself. Severe tears often require surgery, although in some cases alternative treatments may be effective. Physical therapy is a crucial component of post-surgery recovery from these injuries.