Hamstring Muscle Injuries
Hamstring muscle injuries are fairly common in athletes, especially those who play sports such as track, soccer, or baseball. There are several different types of hamstring injuries, all of which affect the muscle group on the back of the thigh. These types of injuries include hamstring pulls, strains, and tendon avulsions. Most of these injuries respond very well to conservative, nonsurgical treatments.
Hamstring Muscle Injuries Anatomy
There are three hamstring muscles that run down the back of the thigh. They are called:
- Biceps femoris
These muscles begin at the bottom of the pelvis and end at the lower leg. It is this muscle group that enables you to extend your leg straight back and bend your knee.
A strain, or pull, on the hamstring, can be partial or complete. Most hamstring strains occur in the central part of the muscle, or where the muscle fibers join the tendon fibers.
Hamstring Muscle Injuries Causes
The main cause of a hamstring strain, or a pull, is muscle overload. This occurs when the muscle is stretched beyond capacity.
Another cause of a hamstring muscle injury is eccentric contraction, meaning the muscle is extended while it is weighted, or loaded. For instance, this can occur when a sprinter takes off; in the act of running, the muscle contracts with the force and weight of the runner’s body, but the physical motion of sprinting also lengthens the muscle.
Hamstring injuries called hamstring tendon avulsions can also be caused by large, sudden loads being placed on the hamstring muscles.
There are also several factors that make it more likely you will have a muscle strain, including:
- Muscle tightness
- Muscle imbalance
- Poor conditioning
- Muscle fatigue
- Choice of activity; runners, sprinters, dancers, and adolescent athletes are at a particular risk of hamstring injuries.
Hamstring strains are more common in adolescents because bones and muscles do not grow at the same rate. If a bone is longer than a muscle, the muscle is already pulled tighter than is natural; a sudden jump, stretch, or impact can tear the muscle away from the bone.
Hamstring Muscle Injuries Symptoms
The most common symptom is sudden, sharp pain in the back of the thigh while the hamstring is extended. This pain will be severe enough to potentially cause a fall or at the very least an immediate shift of weight to your good leg.
Other common symptoms include:
- Swelling during the first few hours after the injury
- Bruising or discoloration on the back of the leg, below the knee
- Weakness in your hamstring that can persist for weeks
Hamstring Muscle Injuries Diagnosis
Your doctor will likely question you about the injury and conduct a physical examination. They will check the thigh for tenderness or bruising. They will apply pressure to the back of the thigh to assess the presence of pain, weakness, or swelling.
Your doctor may use imaging tests to confirm the diagnosis, such as X-rays or an MRI. An X-ray can reveal a tendon avulsion, where a hamstring tendon is injured and pulls off a small piece of bone. MRIs are more useful for taking images of soft tissues.
Hamstring Muscle Injuries Treatment
The treatment of a hamstring injury will vary depending on the type and severity of the injury. The goal of any and all treatment is to enable you to return to the activities you enjoy.
This is the preferred method of healing a hamstring muscle injury.
The first standard method of treatment is the RICE protocol. RICE stands for Rest, Ice, Compression, and Elevation. This can help manage pain and reduce swelling.
Immobilization is another preferred nonsurgical treatment. You may need to wear a knee splint for a brief time.
Once your pain and swelling have reduced to a manageable level, your doctor may prescribe you a physical therapy regimen to restore range of motion and strength.
Surgery is not usually performed for simple pulls or strains and is more common for tendon avulsions, where the tendon has pulled completely away from the bone. Tears on the upper end of the muscle, close to the pelvis (proximal), are more common than tears near the shinbone (distal).
During surgery, your doctor will pull the hamstring muscle back into place and remove any scar tissue that may have formed. Stitches or staples will be used to put the tendon back into place.
Hamstring Muscle Injuries Recovery
Recovery from surgery for a proximal tear takes approximately six months, due to the severity of the injury. For a distal tear, recovery will take about three months. Your doctor will be able to tell you when it is safe to return to sports.
The majority of people who injure their hamstrings recover full function if they stick to their treatment plan. This is also essential to prevent re-injuring the hamstring. If you do frequently re-injure your hamstring, you risk permanent damage.