hamstring injuries

I had the opportunity to talk last week at the Pacers running store in Clarendon (http://www.runpacers.com). Actually, it was the first in a series of talks to be given at the store each month. This month, the topic of discussion was hamstring injuries in runners. I chose this topic because it is a common problem which I frequently see in clinic. JOSPT, which is the sports medicine PT journal, also recently feature an article about a runner who strained their hamstring because of weakness of their glutes.

As with most running injuries, a hamstring injury is typically multifactorial. This injury has historically plagued sprinters because of the huge forces stressing the hamstring during an all-out effort. Most of the research published on hamstring injuries has, consequently, been done on sprinters. However, there is a growing amount of research on middle and long distances runners.The hamstrings are the 3 muscles on the backside of the thigh, just below the glutes. The muscles attach to the sit bone on the pelvis, and inserts below the knee. As a result of crossing two joints, this muscle group performs a variety of functions. The role they play in running is two fold: when the leg is in the air advancing forward, the hamstring controls how quickly the knee extends, and the hip flexes; with the leg on the ground, the hamstring will flex the knee and extend the hip. This is a key distinction because the hamstring muscles must quickly transition from one role to another once the foot strikes the ground. It is during this transitional period that injuries frequently occur.
There are a variety of factors which predispose an athlete to a hamstring injury. One is hamstring weakness. The leg which has weaker hamstrings, especially in eccentric strength, is more vulnerable. A previous hamstring injury will certainly predispose an athlete to re-injury. The reason this is the case is that when a hamstring injury heals, the body lays down scar tissue which is ultimately less pliable than normal tissue. Given the stress that this muscle takes, it is easy to see how this can be a weak link. Poor flexibility in the hamstrings can be another predisposing factor. Poor running form is on the list too. Additionally, poor desk posture can cause an athlete to have tight hamstring muscles which then get strained during running. Poor glute strength will force the hamstrings to work harder. The reason for this is that the glute max and the hamstrings both extend the hip. When the glute is weak, the hamstring will try to compensate. In endurance athletes, a weak glute max can overstress the hamstrings. No amount of stretching or massage will cure this problem til the glutes get stronger.

Given the variety of causes of a hamstring strain, the prevention of them needs to be broad reaching. Here are a few areas to focus on:
1) Strengthen: In particular, focus on strengthening the hamstrings eccentrically. This means working them while they elongate. Use the bicep as an example: you curl the weight up (concentric), and slowly lower (eccentric). A good example of this is placing your heels on a swiss ball, bridging your hips off the ground, curling your knees back, and then SLOWLY letting the legs go straight. Having strong glute muscles will help also so don't forget those.2) Stretch: There are a variety of ways to stretch: actively, passively, and active assisted/dynamically. Think of your warm up as a way to take the leg through a full range of motion to get the blood flowing. Do this prior to your run. Common exercises I do for a dynamic warm up include squats, lunges, and running drills like leg swings, high leg lifts like going over a hurdle, and leg kick outs.Passive stretching is best done after a run. Posture is key with this type of stretching. The hamstring starts at the sit bone and extends down below the knee. As a result, it is important to be aware of what posture the lower back is in. Most runners keep their knees straight and bend over at the waist to stretch their hamstrings. problem is that they are also flexing their lower back which puts slack in the muscle you are trying to stretch. It also puts unnecessary strain on the back. Instead, think of a dowel rod strap to your back so you are forced to hinge at your hips to take a bow. This will certainly elongate the hamstring. Hold 30 seconds, a couple times each side.


Another way to stretch is using a rope around the foot while on your back. The thigh is held perpendicular to the floor. You can use the quad to gently straighten the knee stretching the back of the thigh in the process. When the quad contracts, it naturally shuts down the hamstring so it can be stretched. This is more of an active movement where you straighten the knee as much as you can with the normal curves in the low back being maintained. I typically have people cycle into the stretch and back out versus the prolonged hold on the previous stretch. 10 reps is usually good to go.
3) Posture- Keep in mind it is hard to sit at your desk with suboptimal posture strategies( read -crap) and then expect to go out and have great form and flexibility while running. It is all related. Go back to my post on desk posture and make sure you are in compliance! Also, keep in mind it is a process. You need to create a routine that allows you to consistently come to these exercises and stretches. Over months, not days, these will have an impact.

Sorry for the delay with this, but thanks for reading. As I frequently say, being a good runner requires more than just more miles. When you look at the successful runners, you frequently see a comprehensive training routine that includes quality runs with a focus, plus stretching, strengthening, balance and core work, and form drills. If your head was not already spinning, consider the need for quality nutrition and rest. If these two are not optimal then all other areas will suffer.