Function of the Muscle
The hamstrings are comprised of three muscles: the semimembranosus, semitendinosus and biceps femoris. The hamstrings work in conjunction to flex the knee and extend the hip. The semimembranosus and semitendinosis work to rotate the knee inward while the biceps femoris handles lateral rotation, or rotating the knee outward. In ballet, flexion and extension of the hamstrings is seen when you perform plies as well as arabesques. Ballet dancers consistently work with turned-out hips, resulting in lateral rotation of the knee.
Imbalance
A common problem in dancers is imbalance or asymmetry that can result in hamstring injury. The imbalance could be muscular or structural. An example of structural imbalance is dancing with a tilted pelvis. Muscular imbalance may occur when too much emphasis is put on strengthening the quadriceps muscles, or the front of the thigh, and only stretching the hamstrings. Muscular imbalance could also be a result of only dancing with emphasis on one side of the body, resulting in strength discrepancies between the two hamstrings.
Overuse Injury
Overuse injury can occur simply from working on a specific ballet technique for too long. Without proper strength in the hamstrings, and rest for the muscles, the hamstrings undergo continuous tension and this can result in tears and fatigue. Again, this can result from working continuously on only one side of the body. For example, if your instructor consistently trains you to do everything to the right side without incorporating exercises to the left, you may become injured as a result of over-training the muscles on one side of your body.
Overstretching
Overstretching may sound a lot like an overuse injury, but this is often misunderstood. Ballet dancers have a common theory that because you are having trouble with your hamstrings, or maybe your extension is not long enough, that you simply need to stretch out the tightness. You may stretch and stretch, past the point of comfort, and the next thing you know, you have pulled your hamstring while performing a ballet exercise. A good stretching program is essential; however, look at other issues affecting performance such as imbalance and over-training.
Effective Hamstring Training and Stretching
Incorporate hamstring stretching into your ballet work but do not exclude strength training. You are naturally, repetitively, stretching the hamstrings when doing ballet, so develop a good strengthening program for the hamstrings muscles. Focus on strengthening both sides of the legs equally and incorporate movements in the classroom on both the left and right sides of the body. If you continue to experience fatigue or pain, make an appointment with a physical therapist to effectively manage injury.
