Cycling Physio – Knee Pain

By Roslyn Penfold

Within my sports physio clinic cyclists often present with knee pain. The knee is comprised of 2 major joints; the larger tibiofemoral joint (the articulation between the main shin bone and the thigh bone), and the patellofemoral joint (the articulation between the knee-cap and the thigh bone). Within the cycling community it is the later (PFJ) which is responsible for much of the grief. The other common region for knee symptoms is the outside of the knee, where a structure the iliotibial band (ITB) crosses.

Why are these two regions vulnerable? Every region of the body is designed to move in an ideal manner – that is in correct biomechanical alignment. On the bike there is a best position for your pelvic/hip/knee and foot alignment. Cycling by its very nature is a very repetitive activity. A cyclist covering 140 kms a week will complete around 200000 revolutions of their legs. This in combination with even the smallest error in bike setup and technique will create structural stress and pain.

What is responsible?

  1. Poor biomechanics (your physique) – Some cyclists have slightly malaligned kneecaps, or tight muscles e.g. quadriceps/ITB/calves/buttocks;
  2. Poor mechanics (pedal, spindle or crank fault) – e.g. faulty pedal plate or cleat alignment;
  3. Incorrect seat position – a saddle which is too low will increase the forces behind the kneecap, a saddle too high will increase the forces between the ITB and the bone, both potentially aggravating these structures; and
  4. Poor pedalling technique (covered in the first cycling physio article).

How to prevent knee pain:

  1. Saddle height – the correct position of the saddle, that is height, fore/aft (forwards/backwards) and tilt will ensure forces are optimal (and therefore minimal) at the knee. The two most important factors are when the knee is at its straightest there is about 20º-30º bend, and when the front crank is at 90º the kneecap should be over the pedal spindle (not in front).
  2. Pedals/spindles. Don’t presume your pedals are always going to function perfectly. Check they have a smooth symmetrical rotary action, and that the surface the cleat attaches to is smooth and horizontal.
  3. Cleat position. The correct alignment of your cleats will allow you kneecaps to point towards the front – not in or out.
  4. Stretch. Tight structures from the lower back and buttocks all the way to the feet contribute to forces at the knee. Cycling requires the maintenance of a very restrictive position, potentially leading to the shortening of many structures. Regular stretching will combat this tendency. You will need to stretch the quadriceps, ITB, hamstrings, hip flexors, gluteals and calves.
  5. Cadence. A good quick leg speed will reduce the stress at the knee. Pushing big gears is a sure fire way of stressing out your knees.
  6. Pedalling technique. Good pedalling involves maintaining alignment of your knee over the ball of your foot. To accommodate this you will experience a very slight side to side movement of the knee. If you are unsure about this contact a cycling coach.

    7. Once you have checked all these factors you are well on the way to preventing knee injuries.

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