SORE POIN T

I keep getting saddle sores, but only ever on one side. Is there anything I can do?

“If someone comes in with a leftsided saddle sore, as a physio, you think, ‘It’s an asymmetry issue’”

Human beings are asymmetrical. Bikes, are universally symmetrical… unless you’ve got them set up wrong! Accommodating the asymmetrical rider to their symmetrical machine is a huge part of my job. I’m comfortable with asymmetry, and if it isn’t causing you an issue, I believe in not correcting it as you can cause more problems than you solve. We all have ways of compensating for our asymmetry in our day-to-day lives, but when you transfer yourself to a bike, sometimes those strategies break down.

One of the biggest subjects that cyclists talk about is leg length. There are different approaches to cope with actual leg length differences – where bones, such as your femur or tibia are longer in one leg than the other – and, what in my experience, is more typical: functional leg length difference. This has more to do with the pelvis, lumber spine and the hips. Twists in the pelvis occur for a variety of reasons: exposure to one-sided continual loading, injury or to accommodate our heads and eyes being level. The pelvis irons out our kinks and bends in the spine to achieve this. The consequence is that one leg may be functionally shorter or longer.

When you transfer that to a bike, for some people that functional leg length difference means that one side of the body is sitting further back, or further down, than the other – and that can cause some issues. If someone comes in with a left-sided saddle sore, as a physio and bike fitter you’re already thinking, ‘It’s an asymmetry issue.’ As a physio you would examine them and might discover that they have a back issue on the right-hand side, which has resulted in a twisted pelvis. When sitting on the bike, the only way they can sit is off to the left because the right leg is functionally shorter.

There are different ways this can present, but a common one is that if, for example, the right leg is shorter then they will have to set-up for this leg. The longer leg, in my experience, is not the natural driver for optimal saddle height. This can be seen with the right leg tracking straight up and down, whilst the functionally longer left leg appears to move in and out at the knee a lot more because it has to (the saddle height is effectively too low on the left, so the leg has to move laterally to get through the pedal stroke). Hard correction of this can work by building up the shorter leg under the cleat and raising the saddle height for the longer leg, therefore optimising saddle height for both.

Actual leg bone length differences are rarer and the success of intervening with hard correction is knowing where the difference in bone length lies – thigh or shin? Shin requires cleat build up, whereas with thigh, cleat fore/aft has to be considered. Sometimes asymmetry can be driven by position. A small functional leg length difference can be amplified in its relevance if the saddle height, tilt and set back are all wrong. Sitting too far back, too low and with the nose of the saddle up forces the pelvis to rotate back, robbing the body of some of its compensation for dealing with the asymmetry and making the distance to the pedal further. The individual has no choice but to sit asymmetrically. Hard correction of this situation is papering over the cracks and non-essential – optimising the position to an effective one to pedal in comfortably and efficiently often sees asymmetry drop away.

If you recognise that you’re struggling to reach the pedals, make it easier to reach them. If you reduce crank length, top dead centre decreases and bottom dead cent decreases, so you haven’t got as far to go down or come up and that’s easier on a system that’s already under strain.

These are just rules of thumb, which may help some but not all – you can never beat a one-on-one assessment to deal with individual issues.