Usually the main features of chronic strain injury are that you will feel muscle pain, muscle spasm and muscle weakness. There may also be localized muscle swelling, spasm and, in mild or moderate strains, some loss of muscle function may occur. 1. Chronic strain injuries are usually the result of overuse of muscles: prolonged repetitive movements of muscles and tendons. 2. Common examples of chronic injuries include: tennis elbow, shoulder arthritis in swimmers, knee arthritis in runners and rope jumpers, Achilles tendonitis, tenosynovitis, etc. 3. Most chronic injuries can only be resolved with medication and physical therapy. However, in the short term, anti-inflammatory drugs and painkillers such as celecoxib can only help to cope with the pain and inflammation associated with the injury, and cannot fully restore the lesion. All of the above medications should be done under the supervision of a physician and should not be self-administered.