A muscle strain is the stretching or tearing of muscle fibers. Most muscle strains happen for one of two reasons: either the muscle has been stretched beyond its limits or it has been forced to contract too strongly. In mild cases, only a few muscle fibers are stretched or torn, and the muscle remains intact and strong. In severe cases, however, the strained muscle may be torn and unable to function properly. To help simplify diagnosis and treatment, doctors often classify muscle strains into three grades, depending on the severity of muscle fiber damage:
Although the risk of muscle strain is especially high during sports activities, you also can strain a muscle by lifting a heavy carton or by simply stepping off a curb.
Almost all types of athletic activity carry some risk of muscle strains, but these injuries tend to happen most often in contact sports, such as football, and in sports that require quick starts, such as basketball and tennis.
Symptoms of muscle strain include:
Your doctor will want to know what type of activity triggered your muscle pain and whether there was a pop in the muscle at the time of injury. The doctor will ask about your symptoms, especially any decrease in muscle strength or any difficulty moving.
Your doctor will want to know whether you've had recent fever, weight loss, leg numbness, urinary or bladder problems, or other symptoms that may point to a more severe medical problem.
After noting your symptoms and past medical history, your doctor will examine you, checking for muscle tenderness, spasm, weakness and decreased muscle movement. If this exam points to a mild or moderate muscle strain, you may not need any additional testing. However, if the diagnosis is in doubt, X-rays or magnetic resonance imaging (MRI) scan may be helpful.
If you have back pain, your doctor may order additional tests to check for a urinary tract infection or a problem involving the vertebrae (backbones), vertebral disks, spinal canal or spinal cord.
How long a sprain lasts depends on the location and severity of the injury. Symptoms of a mild back strain usually improve within one to two weeks and are gone within four to six weeks. In the legs, mild or moderate strains may take up to 8 to 10 weeks or more to heal. Symptoms of a severe (Grade III) strain may persist until the torn muscle is repaired surgically.
To help prevent muscle strains:
If you have a Grade I or Grade II strain, your doctor will ask you to follow the RICE rule:
To help relieve muscle pain and swelling, your doctor may suggest that you take acetaminophen (Tylenol and others) or a nonsteroidal anti-inflammatory drug (NSAID), such as ibuprofen (Advil, Motrin and others). For someone with a painful back strain that does not improve with NSAIDs or acetaminophen (Tylenol), prescription pain medications or muscle relaxants may be appropriate.
If you have a severe Grade II or Grade III strain, your doctor may refer you to an orthopedic specialist. Depending on the severity and location of your muscle strain, the orthopedist may immobilize the injured muscle in a cast for several weeks or repair it surgically.
Mild strains may heal quickly on their own, but more severe strains may require a rehabilitation program.
Call your doctor promptly if:
Recovery depends on the location and severity of your muscle strain. In general, almost all Grade I strains heal within a few weeks, whereas Grade II strains may take two to three months or longer.
After surgery to repair a Grade III strain, most people regain normal muscle function after several months of rehabilitation.
National Institute of Arthritis and Musculoskeletal and Skin Diseases
National Insitutes of Health
1 AMS Circle
Bethesda, MD 20892-3675
National Institutes of Health (NIH)
9000 Rockville Pike
Bethesda, MD 20892
American Academy of Orthopaedic Surgeons (AAOS)
6300 North River Road
Rosemont, IL 60018-4262
National Athletic Trainers' Association
2952 Stemmons Freeway
Dallas, TX 75247
American Physical Therapy Association
1111 North Fairfax St.
Alexandria, VA 22314-1488