What is the hamstring muscle and how does it strain or tear?
The hamstrings are a group of muscles at the back of your thigh. The function of the hamstrings is to allow the leg to extend or straighten at the hip and flex or bend at the knee. The hamstring muscles, are paired with the quadriceps muscle in the front of the thigh, to allow us to bend and straighten our leg. When you bend your leg, the hamstring muscle contracts and the quadriceps muscle relaxes. When you straighten your leg, the quadriceps muscle contracts and the hamstring muscle relaxes. It is extremely important that there is a balance between the muscle strength of the hamstring and quadriceps muscles.
The quadriceps muscle is generally more powerful than the hamstring muscle, which means that the hamstring muscle fatigues more quickly than the quadriceps muscle. This fatigue does not allow for a balance in the relaxation and contraction of the hamstring and quadriceps, which can lead to hamstring strains or tears. Hamstring strains in young adolescents often occur because of the different rate at which bones and muscles grow at this stage. During a growth spurt, the bones can grow faster than muscles. As the bone grows, it can create a tight pull on the muscle and during an activity that creates stress on the muscle, the hamstring can stretch or tear away from it’s connection to the bone. Muscle strains can also result from inadequate stretching. This can be a contributing factor of hamstring strains in anyone who does not take the time to warm up prior to activity or training.
Individuals who are susceptible to hamstring strains and tears are:
- Dancers, cheerleaders, etc.
- Runners, sprinters
- Adolescent athletes who are going through a growth spurt
- Athletes: football, soccer, skating, running
- Anyone who engages in activity without adequate warm-up/stretching
Symptoms:
- Sudden sharp pain at the back of the thigh during exercise, usually occurs during a high velocity movement
- Tightness in the back of the thigh
- Pain when flexing the knee against resistance
- Spasm of the hamstring
- Swelling, depending on severity
- Limp or impaired mobility, depending on severity
- Possible gap in the muscle, if there is a complete tear
- Bruising
Diagnosis: Your physician will take a detailed history and thorough clinical exam. In general, hamstring injuries are readily apparent.
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