Definition

A muscle strain is an injury that damages the internal structure of the muscle. It may be small or severe enough to cause internal bleeding and lengthening of muscle fibers. If the damaged parts of the muscle pull away from each other, it is called a muscle rupture.

Muscles of the Back

Nucleus factsheet image

Copyright © Nucleus Medical Media, Inc.

Causes

A muscle strain is caused by tension or stress applied to the muscle that it cannot withstand. There are several ways that this can happen:

    
  • Muscle may not be ready for sudden stress
  • Tension may be too much for the muscle to bear, such as lifting a weight that is too heavy for you
  • Muscle is used too much on a certain day
  • Certain areas have muscles that are more likely to be strained than others, including:

        
  • Hamstrings
  • Groin
  • Back
  • Calf
  • Muscles that cross two joints are at the greatest risk.

    Risk Factors

    Factors that increase your chances of getting a muscle strain include:

        
  • Athletic activities, especially those with running, lifting, and jumping
  • Tight muscles
  • Fatigue
  • Overexertion
  • Cold weather
  • Symptoms

    Symptoms depend on how you strained the muscle.

    Strain While Performing an Athletic or Physical Activity

    You feel immediate soreness or pain in the affected muscle. If you try to use that muscle, it hurts even more. The area becomes tender and swollen. In the most severe cases, there may be a skin bruise because of bleeding underneath. Moving the nearby joints causes pain. Running and lifting are common activities that cause this type of muscle strain.

    Strain from an Accumulation of Stress

    When you do an activity that your body is not used to doing, the muscles are not in shape for that kind of activity. You may not feel pain during the activity, but the next day a muscle or set of muscles may be very sore. The muscle will be tender, and using it causes pain or discomfort.

    Diagnosis

    The doctor will ask about your symptoms, your recent physical activity, and how the injury occurred. The injured area will be examined for:

        
  • Tenderness directly over the muscle
  • Pain when contracting the muscle, particularly against resistance
  • Images may be taken of structures inside your body. This can be done with:

        
  • MRI scan
  • Ultrasound
  • CT scan
  • Treatment

    Treatment depends on the severity of the strain and the muscle involved.

    Treatment usually includes:

        
  • Rest—Do not do activities that cause pain. If normal walking hurts, shorten your stride. Do not play sports until the pain is gone.
  • Ice—Apply cold to the injured area for 15-20 minutes, four times a day for several days after the injury. Do not apply the cold directly to the skin.
  • Compression and elevation—This can decrease swelling.
  • Oral nonsteroidal anti-inflammatory drugs (NSAIDs) to relieve pain and topical pain medicines, such as creams and patches, applied to the skin—If you still have muscle tenderness while taking these drugs, do not return to physical activity and check with your doctor.
  • Heat—Use heat only when you are returning to activity. Then, use it before stretching or getting ready to exercise.
  • Stretching—When the acute pain is gone, start gentle stretching. Stay within pain limits. Hold each stretch about 10 seconds and repeat six times. Repeat stretching four times a day.
  • Strengthening—When a muscle is injured, it becomes weaker because it is not used. You must gradually regain strength. It is best to do this under the supervision of a healthcare professional. You may be referred to a physical therapist.
  • If you are diagnosed with a strained muscle, follow your doctor's instructions .

    Prevention

    To reduce your chance of straining a muscle:

        
  • Keep your muscles strong so they can absorb the energy of sudden stressful activities.
  • After a short warm-up period, stretch out tight muscles, especially previously injured ones.
  • Learn the proper technique for athletic activities to decrease muscle stress.
  • Stop when you are tired. Tired muscles do not function well. They do not react properly to sudden stress.