A pulled muscle behind the knee, or muscle strain, can range from mild discomfort to a complete tear. This injury affects several muscle groups susceptible to damage from overstretching or sudden force. Understanding the muscles involved, how these injuries occur, and their symptoms can help in treatment and prevention.
Muscles Behind the Knee
The hamstring group is the primary muscle group frequently strained behind the knee. These three muscles—biceps femoris, semitendinosus, and semimembranosus—run down the back of the thigh. They bend the knee and extend the hip, movements essential for walking, running, and jumping. The gastrocnemius muscle, part of the calf, also sits behind the knee and contributes to knee bending and pointing the toes downward.
How These Injuries Occur
Muscle strains behind the knee occur when the muscle is stretched beyond its capacity or subjected to sudden, forceful loads. Activities like rapid acceleration, sprinting, or forceful knee extension (e.g., kicking or dancing) can cause these injuries. Inadequate warm-up routines make muscles less flexible and more prone to strain. Muscle fatigue or imbalances, where one muscle group is significantly stronger than its opposing group, also increase injury risk.
Recognizing the Symptoms
A pulled muscle behind the knee causes sudden, sharp pain in the back of the thigh. Often, a “popping” or tearing sensation accompanies the injury. Swelling, tenderness, and bruising can develop within hours or days. There may also be difficulty bending or straightening the knee, and weakness in the affected leg. Muscle strains are categorized by severity:
Grade 1: Minor fiber damage with minimal strength loss.
Grade 2: More extensive tearing and reduced strength.
Grade 3: Complete muscle rupture with significant loss of function.
Treatment and Recovery
Initial management for a pulled muscle behind the knee involves the RICE protocol: Rest, Ice, Compression, and Elevation. Resting the injured leg prevents further damage. Ice reduces pain and swelling. Compression bandages minimize swelling, and elevating the leg above heart level reduces fluid accumulation. Seeking professional medical attention is advised for severe pain, significant bruising, inability to bear weight, or persistent symptoms. A healthcare provider can assess the injury, rule out other conditions, and recommend a tailored rehabilitation plan. This plan progresses from gentle stretching and isometric exercises to controlled strengthening activities as pain subsides.
Preventing Future Strains
Preventing future muscle strains behind the knee requires physical preparation. Proper warm-up routines before physical activity increase blood flow and elasticity, reducing injury risk. Regular stretching, particularly focusing on the hamstrings, maintains flexibility. Strength training that balances muscle groups, especially hamstring strength compared to quadriceps, reduces vulnerability. Gradually increasing exercise intensity and duration allows muscles to adapt safely.