Hamstring Injuries

Are you hamstrung before you start?

One of the most common injuries in running is to the hamstrings. Or typically, the pain often presents itself in the hamstrings due to biomechanical load from another area that is not functioning correctly. Even if you tear the hamstring during sprinting, the underlying cause is usually biomechanical, and unless that cause is addressed the problem will become recurrent or simply just not go away. You could even just have a hamstring that feels tight or won’t stretch out properly, either way the cause is usually biomechanical.

Often these biomechanical causes are due to the pelvis. A ‘rotated’ pelvis, (which is where the pelvic bone gets stuck in an abnormal position) can go unnoticed for many years until the compensations start to cause problems. Typically this is caused by unaccustomed lifting or carrying, performing a repetitive movement abnormally or perhaps compensating for another biomechanical issue elsewhere in the body. When the pelvis rotates, the piriformis muscle on the outside of your hip goes into a protective spasm. This spasm effectively prevents the joint from functioning correctly and so other areas have to compensate. If the problem is caught early enough, treatment will help. If however the problem is left for more than 6 weeks, the muscle will change its composition and become fibrotic and be unable to function normally. In theses cases treatment will help in the short term, but whenever you start training again, the problem recurs.

This background commonly affects the hamstring – this is how. The problem is that when the piriformis muscle goes into spasm, it causes the sciatic nerve to become tight. It does this because the pelvis doesn’t move as well as normal, so the nerve becomes stiff and also because the nerve can run through the very muscle that’s in spasm. The body cannot allow damage to the sciatic nerve, its one of the main nerves in the body, so the muscles that would protect it go into a protective spasm. One of which is the hamstring group.

This protective spasm of the hamstrings can cause a number of problems that cause symptoms in the hamstring itself. It can make the hamstring feel tight and stiff. It can make the hamstring feel inflexible as it’s under constant tension. It can also cause a functional muscle imbalance. In other words, if the hamstrings are found to be ‘weak’ in comparison to the quadriceps (quads), one of the causes of this muscle imbalance could be the inability of the hamstring to fire correctly due to its state of tension, rather than it being fundamentally weak.

To manage this cause we first have to return the abnormal muscle tone in the piriformis muscle to normal. In other words you have to do ‘anti-spasm’ exercises for the muscle. Stretching or flexibility work just won’t cut it. You need to return the muscle to normal function, not just stretch it. That is why stretching the hamstrings isn’t always the answer to your hamstring problems. In fact stretching or mobilizing your sciatic nerve is far more effective in these cases. Once the spasm is eradicated as much as possible, then you have to perform exercises to stabilize the pelvis. In other words exercises that allow your muscles to control your pelvis and trunk without them needing to go into spasm. Part of this process is achieved by so-called ‘core stability exercises’, but also you need to speak to your physio about plyometric exercises for pelvic muscles that you can do in the gym.

This is usually sufficient to eradicate the hamstring pain is gradual in onset. In the case of a hamstring tear which was caused by a high velocity movement like sprinting; it may well be necessary to follow this with a progressive hamstring rehabilitation program as well. But unless the biomechanical cause have been eradicated, then that process is unlikely to be successful.

There are other causes of hamstring pain, this is only one, but it is common enough for you to need to understand it, especially if you problem is not going away.

A CD ROM software program that helps you asses your biomechanics with the software prescribing the exercises needed to remove these biomechanical problems and in turn help manage and prevent the types of hamstring injuries we’re talking about in this article is available from HumanLab Sports, as a result of one of the largest studies in to biomechanics ever undertaken. Go to www.humanlabsports.com

Managing Director of HumanLab Sports, heading a team of bio mechanists, kinesiologists, physiotherapists, strength and cardio-vascular specialists.