Muscle pulls, or more accurately strains, are the most common injury sustained in sports.
A muscle strain typically occurs suddenly with rapid onset of pain. Most often, the mechanism is a rapid contraction of the muscle group while it is getting longer. A very common occurrence is a hamstring strain that happens when the leg is swinging forward and the heel hits the ground at the same time that the muscle rapidly contracts.
The muscle stretches to the point of failure and a strain occurs. The most common muscle strains are the hamstring, the quadriceps (muscle group in the front of the thigh), and the gastrocnemius (the main calf muscle). Other less common muscle strains are the hip flexors (muscle group in the front of the hip) and gluteus maximus (the muscle in the buttocks). The weakest point in the muscle and tendon is the myotendinous junction, which is where the muscle blends into the tendon. This region is typically at the middle of the muscle belly. Just for clarification, muscles get strained and ligaments get sprained.
Diagnosis of a muscle strain is usually quite straightforward as a patient will describe a specific event where the pain started suddenly and is located directly at the middle of the muscle belly. Often a patient will describe an inability to continue to bear weight or difficulty walking and trouble with stairs. On examination, the muscle belly will be swollen and there is often bruising. There is often tenderness at the region of injury. In more severe injuries, there may be a defect or empty space where the muscle should be. This represents a high-grade muscle strain. When the injury is in the middle portion of the muscle, it is most often a strain. However, if the pain and injury location is closer to the bone, it could be an avulsion or a pulling away of the tendon from the bone. This typically causes more severe loss of function of the joint. If an avulsion is suspected, it is best to have x-rays to be sure that a piece of bone hasn’t been pulled off with the tendon.
There is a grading system for muscle strains:
- Mild or grade 1 where the loss of function and pain is minimal;
- Moderate or grade 2 where the muscle strain creates more pain and has some inability to function; and
- Severe or grade 3 where there is significant loss of function.
Most muscle strains will take 4 to 6 weeks to heal. With proper treatment, the recovery can be closer to the 4-week time frame than the 6-week time frame. The key to treating muscle strains is reducing activity level and resting the muscle group. Often immobilization of a calf strain with a walking boot can help speed recovery. For hamstring and quadriceps injuries, crutches are often necessary. There is evidence to suggest that if there is a need for crutches, the recovery will be prolonged. This seems like common sense.
Keep in mind: prolonged immobilization of over 14 days should be avoided. The initial immobilization should only occur up the point where pain and swelling has reduced enough to allow return to everyday activities. The RICE principle (rest, ice, compression and elevation) is also helpful for muscle strains and should be started immediately after injury. Physical therapy to help with return of motion and strength can be critical to speed recovery. Returning to sports should only happen when there is full, pain-free motion and there is no pain with normal activities such as stairs and walking. All muscle strains have a high rate of recurrence. Rushing back to activities too soon can lead to re-injury and increasing the total time for recovery.
Prevention of muscle strains is challenging and there is conflicted reports on whether stretching is helpful or potentially harmful. There is evidence to suggest that performing a brief warm-up followed by a stretching program about 15 minutes prior to physical activity is safe and may reduce the chance of muscle strain. Whenever there is sudden onset pain in a muscle group with limitations in motion, it is best to be evaluated by urgent care or a sports medicine professional.
David K. Lisle, MD, CAQSM, is a sports medicine physician at the University of Vermont Medical Center’s Orthopedic and Rehabilitation Center. He is also an assistant professor in the Department of Orthopaedics and Rehabilitation and the Department of Family Medicine.