The Hamstrings
Don't pull a hammy!!!!
HAMSTRINGS =
Yup the ol' hamstrings. Really a bunch of individual muscles, but I thought I would introduce them as a group. Nobody goes to the gym and says they're gonna work out their biceps femoris today. In fact, nobody says "It's hamstring day!" either. Weird.
I bet you're wondering why call them "hamstrings." Is it because human flesh looks and tastes a lot like pork flesh??? Unfortunately, no. According to Wikipedia the name comes from some old English word "ham" or "hom" meaning the hollow crooked bend in a tree with the "strings" obviously referring to the tendons behind the knee that feel like cords.
That hollow place behind your knee is actually called your popliteal fossa, and it houses all kinds of important stuff. The medial and lateral borders are those hamstring tendons and between is an important highway of nerves and blood vessels that supply the lower leg. This location behind the knee offers some protection from major injury to these essential structures.
If you put your hand back in the popliteal fossa you will feel three distinct "strings" or tendons. The outer tendon, by itself, belongs to the biceps femoris. While the pair of tendons on the inner aspect are the semimembranosus and semitendinosus from medial to lateral. In between you can probably find a pulse on your popliteal artery.
HOW TO AVOID PULLING A HAMMY
Hamstring injuries are incredibly common and notoriously hard to rehab. We've all probably felt it, and it's disappointing to see your favorite athlete go down clutching their hamstrings because you know it might be weeks before they are on the field again (except for soccer players who are sometimes miraculous healers after being carried off the field on a stretch). So what is this injury and how can we avoid it?
Simply put, it is a strain or a tear of one or more of the hamstring muscles. Well, duh. There are three grades from a simple cramp in the muscle (which can be a local build-up of lactic acid or other local electrolyte abnormality that causes pain) that is relieved with rest and time to a full tear of one or more of the muscles with the two pieces of the muscle contracting up into a ball on either side of the gap in the muscle. The latter is accompanied by a lot of bleeding which will for a bruise as well as muscle deformity. Mostly what we are talking about when referring to a "pulled hamstring" is on the lower end of the spectrum from a local cramp to a minor tear.
Here are some things you can do to avoid this dreaded injury...
Warm-up. Most hamstring injuries occur when in a full sprint. Here the hamstrings are working at rapid speed under full stretch with near maximal contractions. This is much different than a simple walk or slow jog. The range of motion of the knee is so much greater in a sprint than in a walk with the knee flexing so much, sprinters look like they are kicking their own butts. This high speed of contraction and range of motion cannot be accomplished without maximal blood flow to the muscles. "Warming up" means gradually contracting the muscles up to game speed in order to dilate blood vessels. A "warm" muscle is both more pliable to handle the stress and has more blood flow to deliver oxygen and clear lactic acid. Warming up really does help.
Stretching. From a mechanical stand point probably not all that helpful in preventing an injury right before you exercise. Think about it. Proper stretching causes microtears in the connective tissue of the muscle, that when repaired, result in a longer muscle at rest. This is probably not what you want to do right before stressing the muscle and hoping that you don't partially or fully tear your hamstring in a dead sprint. That's not to say stretching doesn't help, just don't do it right before you play. As mentioned, normally your hamstrings do not go through the full range of motion of a full sprint during your day-to-day activities which usually involve a lot of sitting with knees flexed. This is a very shortened position for your hamstrings and they may not like the full hip and knee extension that comes with the long strides of a fast break. Flexible hamstrings are good because they are ready for activities. Weekend warriors shouldn't be surprised when they injure their hamstrings after a sprint after sitting all week.
Strengthening. Your hamstrings do not bear weight or need to contract very hard under walking conditions. There they are responsible for breaking the knee swing and little contraction at push-off. When sprinting, on the other hand, the hamstrings have to eccentrically contract to slow the rapid knee extension (from the quads) and then as soon as the foot hits the ground rapidly contract the knee to pull the ground with the foot as well as a contract so the hip extends pulling the body weight over the hips. It's eccentric contraction followed by concentric contraction at much faster speeds than you would ever asks your biceps brachii to do with your body weight and velocity to contend with. Imagine doing (arm) bicep curls as fast as your knees flex when you run. Allt this velocity and mass equals huge forces acting on the contracting hamstrings when running. This means strong hamstrings are a must if your sport involves sprinting. Just asking your hamstrings to handle that load once a week is too much.
