"I think I pulled a muscle doing gong fu stances."

The hamstrings are a group of muscles that comprise the following four muscles: long head of the biceps femoris, short head of the biceps femoris, semitendinosis, and the semimembranosis. These four muscles lie in what's called the posterior compartment of the thigh, a compartment being an actual space enclosed by fascia. All four muscles originate from the ischial tuberosity, which, is that bony part of the pelvis that, well, that you sit on. The four muscles of the hamstring group then travel down the back of the thigh, and end on the upper part of the tibia, the two parts of the biceps femoris end on the upper lateral portion of the lower leg, the semimembranosis and the semitendinosis end on the medial aspect. The purpose of these four muscles is to flex the upper leg, ie, if one were to lie down, the hamstrings would be responsible for lowering a raised leg. They also play a key part in the locomotion aspect of walking, and do provide structural integrity for the knee area. The short head of the biceps femoris is inervated by the peroneal nerve, which arises from the L5, S1-S2 levels of the spinal column, the remaining three hamstring muscles are innervated by the tibial division of the sciatic nerve, which also arises from the L5, S1-S2 levels. Injury to lumbar discs in this region can cause innervation loss to the hamstring muscles, with resutling weakness.

From looking at the anatomy pictures, and understanding the purpose of the hamstring muscles, one can see that these muscles can be easily damaged during certain types of gong fu maneuvers, particularly, any motion that is going to cause hyperextension of the upper leg. Maneuvers such as the various Ti Tue (kicks), particularly the basic front kick, whereby one kicks one's foot as high up as possible in front of him (the monks can touch their faces with their lower legs), or the front kick whereby one kicks in a similar fashion, but, with the purpose of crossing the body (ie, having the right leg traverse the body so that the lower leg aims towards the left shoulder). These maneuvers, especially in the improperly warmed up muscles, put a lot of stretch and tension on the hamstrings in the posterior compartment. The result can be stretching and tearing of muscle fibers. Less commonly, tearing of the tendons that attach the hamstring muscles to the ischial tuberosity can occur. Rarely, chip fractures of the bone where tendons attach, can occur.

The problem with this type of injury, is that it takes time to heal. As with all muscle strains and tears, rest, elevation (to diminish swelling, swelling which, if allowed to proceed unabated, can cause increase pain), an initial period of ice packs (24 to 48 hours) to diminish swelling, followed by warmth to promote resolution of swelling, and promote healing, is all indicated. The location of the hamstrings, and the depth of their insertion point, make application of ice and warmth difficult. But the real kicker is, the fact that it's hard to rest these muscles, as they are necessary for locomotion. The more severe the initial tear, the longer it will take to heal. Because of these factors, it might take weeks to months for someone with an injury in this area, to feel normal. Especially if there is tendon damage.

Massage is a good thing, provided that it is not done in a fashion which aggravates the injury. Non-steroidal anti-inflammatory agents also do a nice job of alleviating swelling and pain. Taking narcotics so that one can continue to work out is a real bozo no-no, as the diminution of pain realization just allows one to exagerate motion in the injured area, which can actually increase tissue damage, and further delay healing. Pain is a good thing actually, it reminds us to take it easy, and rest an injured area.

To promote good healing, three things are necessary: good nutrition, rest, and time. Everything heals with time. Continuing with Ti Tue's, as you have probably figured out by now, does not provide adequate rest. Some easy training is in order for a period of time; that period of time is mostly decided upon by how you feel.