Technique: How to deal with different length legs
By Triathlon Plus | Monday, February 15, 2010 4.00pm
Many riders have one leg slightly shorter than the other © Evgenij Gorbunov - Fotolia.com
Many riders have one leg that's slightly shorter than the other. For most people the difference is minor but for others, especially those who have suffered broken bones, it can sometimes be measured in centimetres rather than millimetres.
Here two experts, CycleFit technician Julian Wall and orthopedic surgeon Stephen Eastaugh-Waring, explain what you can do about it.
Bike fit options – Julian Wall
The first thing to look at is your bike setup, and a proper cycle fit by a qualified technician could help in several ways.
One of the most significant fixes would be through adjusting the position of the cleats. I would recommend moving the cleat position further forward on the shorter leg. The fore and aft of the saddle position would also make a difference here.
There are also cleat shims; thin plastic wedges that you can fix underneath the cleats, which mean you can correct leg-length discrepancies, but I’d advise you to always look at cleat position first.
Saddle choice is another factor; if your hip drops on one side it can be improved by a wider saddle, which can help to stabilise the pelvis. We also make custom footbeds for cyclists, which is another area that may help you.
It’s not simple to diagnose yourself; there are lots of factors to consider. Ideally you need someone experienced to take an objective look at you cycling. But the good news is that a proper bike fit can really help to make a huge difference to your cycling.
Medical options – Stephen Eastaugh-Waring
Having a short leg when you’re taking part in sports creates biomechanical problems, and can really restrict your ability to compete. In the case of a short tibia (lower leg) it is more common and more easily addressed with orthotics and shoe inserts. However, femoral (thigh) shortening is more of a problem.
Whatever you do with shoes, crank lengths and seat positions, the problem will still be that the knees are at different levels, thereby upsetting the body’s mechanics. This gives different levels of power transmission through pedal rotation, and tends toward stresses and curvature through the lower back at the lowest point when you’re pedalling.
So what can you do? We’ll leave the issues of bike setup until later (see Julian Wall’s section below), and will look at more long-term solutions. Choosing to have a surgical procedure depends on how short the femur is, residual deformity at the healed fracture site, and any abnormality of limb alignment. If there is malalignment, correcting this will help to prevent early wear and tear in the knee and lower back (constant malalignment of the lower back to compensate for the differences in leg length can lead to permanent deformity or more commonly, degenerative changes and pain).
Your choice of surgical options is between shortening the ‘normal’ leg or lengthening the short limb. The amount you can lengthen it is limited by the degree of difference between the limbs, and tends to involve greater risk. Most lengthening procedures mean you have to use an external fixator or frame, which can be cosmetically and practically limiting. The amount of time you’ll need to lengthen your leg is measured in weeks and months, and complications from infection are common, as are soft tissue scars.
Shortening the good leg sounds counterintuitive, but has many benefits. The amount of time you’ll need to invest for surgery and recovery is relatively short, measured in a few weeks. The ‘osteotomy’ or shortening site is often held together with a nail or plate fixed internally, and this can be done through small incisions, minimising cosmetic issues, and making life more practical during recovery.
The accuracy of equalising the leg lengths is good, with most studies showing restoration to within 1cm, from a difference as great as 4-8 cm. The maximum length difference that can be safely addressed is up to 16cm. Complication rates are fairly low, and you could be back out on your bike within around three months of having the procedure done.
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