What is a pulled hamstring?
A pulled hamstring is a soft tissue injury known as a strain. Strains can involve just the muscle fibers or can also include tendons. Tendons are strong bands of connective tissue that attach muscles to bones. Flexing a muscle pulls on the tendon, which moves the bone.
The hamstring muscles run down the back of the thigh. There are three of them—biceps femoris, semimembranosus, and semitendinosus. The top of all three attach to the bottom of the pelvic bone. The bottom of the biceps femoris attaches below the knee to the fibula. The bottom of the other two attach below the knee to the tibia, or shinbone. Flexing or contracting these muscles lets you extend your leg straight backwards at the hip and bend your knee.
Doctors grade a strained hamstring based on its severity. Grade 1 is a mild hamstring pull. Grade 2 is a partially torn hamstring. Grade 3 is a complete hamstring tear. These injuries usually affect the center, or belly, of the muscle or the area where the muscle and tendon meet. Very severe injuries—avulsion injuries—can even tear away a piece of bone with the tendon. The more severe the injury, the more pain and other symptoms you will have.
Most hamstring strains happen with a sudden muscle overload or overstretching. The load stresses the muscle beyond it capacity and the tissue fibers give way. This scenario can occur during sports that require sprinting or explosive forward movements.
See your doctor if you have a mild or moderate hamstring injury. Seek immediate medical care (or call 911 for assistance) if you, or someone you are with, have symptoms of a severe hamstring pull or tear including:
Feeling a popping or tearing sensation during the injury
Feeling sudden debilitating pain in the back of the thigh that causes you to immediately stop or fall
Inability to use the muscle
What are the symptoms of a pulled hamstring?
The symptoms you experience will depend on the extent of the hamstring injury. Hamstring strains usually result in very noticeable symptoms.
Common pulled hamstring symptoms
Pain in the back of the thigh is almost always present with a pulled hamstring. The pain is sudden and usually causes you to stop your activity. You may end up limping on the other leg with a mild strain or falling to the ground with severe strains and tears. Other common pulled hamstring symptoms include:
Bruising, which can run down the back of the leg and even below the knee
Limited range of motion
Muscle cramping or spasms
Symptoms that might indicate a serious condition
In some cases, hamstring strains can be serious. Seek immediate medical care (or call 911 for help) if you, or someone you are with, have any of the following serious symptoms including:
Complete loss of muscle function
Sensation of tearing or popping during the injury
Severe, debilitating pain
Accessing medical care immediately after the onset of symptoms gives you the best chance of a successful recovery and return to activities.
What causes a pulled hamstring?
A pulled hamstring results from a sudden, forceful muscle overload or when you stretch the muscle beyond its capacity. The muscle is not able to sustain the stress and muscle or tendon fibers overstretch or tear. This commonly occurs when the muscle is both extended and weighted with a load. The name for this is eccentric contraction. The hamstrings do this when your leg is extended and you push off with your toes.
What are the risk factors for a pulled hamstring?
A number of factors increase the risk of developing a pulled hamstring including:
Muscle fatigue or weakness from poor conditioning
Muscle imbalance between the hamstrings and the quadriceps—or quads—muscle group on the front of the thigh. The quads are typically a stronger muscle group than the hamstrings. This means the hamstrings can fatigue earlier than their more powerful opposing muscles, which increases the likelihood of a strain.
Muscle tightness and lack of flexibility
Prior hamstring injury
Certain athletes also have a higher risk of straining a hamstring. This includes dancers, runners, sprinters, and those who participate in sports that require bursts of speed, such as tennis, soccer, football, hockey and basketball. Older people who only walk for exercise tend to have a higher risk, as do teens who are still growing. In teens, the thigh bone, or femur, can grow faster than the hamstring muscles. The longer thigh makes the muscles tight and more prone to strains.
Reducing your risk of a pulled hamstring
You may be able to lower your risk of pulling, straining or tearing a hamstring by:
Avoiding strenuous activities when your muscles are already fatigued or weakened
Cross-training with a variety of activities
Maintaining good physical conditioning, flexibility, strength, and a healthy body weight
Strengthening your hamstring muscles to promote muscle balance with the quads
Warming up appropriately before physical activity
If you are at risk of a pulled hamstring, talk with your doctor about ways to protect yourself. Consider working with an athletic trainer to achieve proper muscle balance and flexibility.
How to treat a pulled hamstring?
Pulled hamstring treatment goals are to relieve your symptoms, heal the muscle, and return you to your activities. Most of the time, you can accomplish this with home treatment. This includes RICE (rest, ice, compression and elevation) and NSAIDs (nonsteroidal anti-inflammatory drugs), such as ibuprofen (Advil, Motrin) and naproxen (Naprosyn). NSAIDs work to reduce swelling and ease pain. You may also need a splint to keep your knee from bending, which will also keep the hamstrings from contracting. You may even need to use crutches or a cane to keep your body weight off the hamstrings while they heal.
Physical therapy can begin after the pain and swelling have subsided. You will learn exercises to stretch the muscles, increase flexibility, and restore range of motion. Then, you will focus on strengthening the muscles.
Surgery is necessary if the tendon has completely torn away from the bone. Your doctor may also recommend surgery if the muscle itself has completely torn.
Pulled hamstring recovery time depends on the severity of the injury. A mild strain usually heals within a couple of weeks. Severe injuries involving tears can take months to fully heal.
What are the potential complications of a pulled hamstring?
Most pulled hamstrings heal successfully without complications. However, this relies on your dedication to your treatment and recovery plan. Without adequate pulled hamstring recovery, reinjury of the muscle can occur. Doing too much too soon can also lead to permanent damage and chronic problems. Seeking early medical care and carefully following your doctor’s treatment plan is the best way to prevent these complications. Only return to sports and other activities when your doctor says you are ready.