Muscle strain or a “pulled muscle” results due to improper use or stretching or fatigue of the muscle fibers leading to a partial or complete tear of a muscle. These strains may occur in any part of the body but usually seen in the lower back, hamstring region, shoulder and neck region. Seen commonly in athletes, runners during intense training/activity phase.
Muscle strain can occur when the force of contraction is so great that it causes the muscle fibers to tear. The tear can occur in the muscle substance or at the place where the muscle attaches to the tendon (a portion of the muscle that attaches it to the bones) or in the tendon region. These injuries commonly occur during excessive loading of the muscle; that is when the muscle is contracting while it is elongating. Muscles that cross two joints, such as the hamstrings (the hip and knee joints), the calf (the knee and ankle joints), and the quadriceps (the hip and knee joints) are the most susceptible to injury. Factors that can predispose an athlete to injury include older age, previous muscle injury, less flexibility, lack of strength in the muscle, and fatigue. Many athletes sustain muscle injuries when they just begin a training regimen. Strained muscles are prone to injury in the future.
Grades of Muscle Strains
The severity of a strain can be assessed by how much strength and range of motion a person loses, and this can also provide an idea as to how long it will take to recover. Muscle strains can be categorized into three grades, based on severity:
- Grade 1: Mild damage to individual muscle fibers (less than 5% of fibers) that causes minimal loss of strength and motion.
- Grade 2: More extensive damage with more muscle fibers involved. However, the muscle is not completely ruptured. These injuries present with significant loss of strength and motion. These injuries may require prolonged rehabilitation before returning to sporting activity.
- Grade 3: Complete rupture of a muscle or tendon. These can present with a palpable defect in the muscle or tendon. However, swelling in the area may make this difficult to appreciate. These injuries sometimes require surgery to reattach the damaged muscle and tendon.
Symptoms and Signs
- Sudden pain that worsens while using the muscle
- Swelling and bruising ‘a knotted up’ sensation
- Loss of strength and range of motion or stiffness
- Bruising or discoloration
History and physical examination. In severe, grade 3 cases, the examining physician may actually be able to feel the defect where the muscle has completely torn.
X-ray is done to rule out underlying fractures, dislocations or avulsions Occasionally in young athletes, the tendon can pull off a piece of bone where it attaches, which can be seen on X-rays.
MRI is done to see the injuries which are in the substance of muscles and to see the severity of the injury. MRIs can also show collections of blood, called a hematoma, that sometimes occur following severe injuries.
Low grade or partial tears are generally managed with RICE therapy
- Rest the muscles and avoid activity causing contraction of the injured region
- Ice pack application can reduce pain and inflammation
- Elevation of the injured region
- Activity modification- Avoid the repetitive activity causing stress.
- NSAIDs –reduce inflammation and pain
- Ultrasonic diathermy application, Interferential therapy
Most muscle strains do not require surgery, and a full recovery is expected.
If there is a partial tear then the athlete can return when they are pain-free and have normal strength and motion. This usually occurs following anywhere from a few weeks to a few months of appropriate treatment and therapy. These treatments will be done for the first week, followed by progressive functional physical therapy, as needed.
Surgery and platelet-rich plasma injections
Complete muscle injuries can lead to significant functional impairment and lost playing time and may require surgical repair. This is especially the case for patients who need to be able to run or be sufficiently agile to participate in sport.
PRP (Platelet-rich plasma) Injection- Patients whose symptoms persist, or who do not achieve adequate relief from these measures, may be candidates for an injection
Returning to Sports and Activity
Return to full activity is usually allowed when the patient is pain-free, has a full range of motion, and full strength. If an athlete attempts to return to their sport before these criteria are met, there is a high chance of reinjuring the muscle and sustaining a setback. Mild, grade 1 injuries may require only two to three weeks before an athlete can return. More severe injuries may require significantly more time.