Monday, 24 December 2012

Pelvic bio mechanics. A few answers.

To wedge or not to wedge??Is this the answer??

there are times when they are not. Take the example of the wedging of the feet in the pedal in an attempt to correct an overly flat foot in the shoe or cleat. Bearing in mind that 60% of the biomechanical problems that exist in feet are compensations for faulty biomechanics in the pelvis or hips, then you can see that it’s critical to ensure that the hips and pelvis are fully functional before the feet are addressed.

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 a rotated pelvis 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.

The body can compensate in a variety of ways for the rotated pelvis causing a leg length discrepancy, causing a variety of potential problem areas.

Common examples are that the foot can flatten to shorten the length of the longer leg or the opposite foot can increase the height of its arch to lengthen the shorter leg. Alternatively the knee of the longer leg can bend more to shorten it, or the knee of the shorter leg can bend less to lengthen it. In addition, the spine can side bend more to allow the shorter leg greater reach. These are only some of the many ways the body tries to compensate for a leg length discrepancy. Also bear in mind that the problems are worse in cycling than many other sports as you are fixed in a position determined by an external factor, unlike with running where you are relatively free to compensate how you like. All of these compensations though will increase the load on the structures that are doing more work. Typically they will result in knee pain, back pain, thigh or hamstring pain and hip pain. Moreover they make it very difficult to set your bike up correctly, as how do you know whether to set the seat/pedal relationship right for the longer leg or the shorter leg?

To manage these issues, we first have to return the abnormal muscle tone in the pelvis (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. Once the spasm is eradicated as much as possible, then you have to perform exercises to stabilise 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 health care provider about plyometric exercises for pelvic muscles that you can do in the gym.

Once your pelvis is in good shape, and if you continue to get problems with your troublesome body part, then you can safely get a qualified practitioner or specialist to consider prescribing the wedges.

So if anyone says to you that wedges in your shoes can help with your knee, back or hip pain, you must make sure that they check your pelvic biomechanics first.
For a full bio mechanical assessment, book an appointment with Andy or Jason, our fully qualified Bio mechanical coaches.

Writen by ITS.

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