Q: I have been diagnose with patella-femoral syndrome, and I have just finished an aggressive course of physiotherapy. I want to get back to cycling, as soon as possible. How should I adjust my bicycle to avoid knee re-injury ?
A:
Cycling can be either a good or bad sport for patella-femoral syndrome. If your re-introduction to cycling is gradual, accompanied by appropriate warm-up and stretching, and your bicycle is adjusted properly, you can minimize your chance of re-injury.
Bicycle Set-up involves six components:
Bicycle Size
- Make absolutely certain that your bicycle frame size is appropriate for your body size. Most people tend to buy bicycle frames too large. As a consequence, it can be very difficult to maintain the proper ergonomics for minimizing injury. It is best to always seek professional advice when buying a bicycle, to ensure that sizing is correct. This can be particularly difficult for women, who may need special modification to the bicycle to maintain proper sizing.
Bicycle Size
- Repeated for Emphasis
Bicycle Size
- Am I getting my point across ?
Seat Height
- A proper seat height minimizes the force placed on th bent knee (the common denominator for pain due to patella-femorala syndrome). Although it is best to have seat height adjusted by a professional, your seat should be high enough that with the pedal in the lowest position, and your heel on the pedal, your leg should be fully extended (but not locked or hyper-extended). If you find that your seat is too low as it is now, you may need to raise it slowly, a few millimeters every few days, to changes in pedaling style.
Seat Fore/Aft Adjustment
- The saddle should be in position such that the anterior knee-cap is exactly straight over the pedal axle when the pedals are at the 3 O'clock position. It can be very difficult to adjust this on your own, and professional guidance may help. In addition, especially in mountain biking, riders tend to slide fore and aft on the saddle during the ride, so this measurement done at home may not replicate the situation while riding.
Cadence
- Cadence, the number of revolutions the pedals are turned, is an important factor for avoiding knee pain. A quick review of high school physics will show that by doubling the cadence, you can maintain the same ground speed using half as much force on the pedals. Thus, by keeping cadence high, you can reduce the magnitude of force placed with each pedal stroke. While many recreational riders will pedal at 40-80 rpm, most professional riders will pedal at a minimum of 100 rpm, and ideally closer to 120 rpm. Although it can take some time to increase cadence, maintaining a cadence of >80 rpm is mandatory for riders with knee problems.
Pedal 'float'
- Whether pedal 'float', (the ability to rotate the ankle in and out) is helpfull for patella-femoral disorder is unclear. However, it is important that the ankle is aligned in a neutral (comfortable) position throughout the pedal stroke. This may require 'floating' pedals for some riders. In general, unless you are using clipless (step in) pedals, this isn't a concern.