Cycling is a part of many of our lives, whether you’re the regular in the spinning class or a racing snake on the trails. No matter how long you’ve been riding or how serious you are about it, the correct pedal stroke is fundamental to a good performance and limiting injury.
I recently joined a session at training lab, Cycle Zone, in Rosebank, Johannesburg where biokineticist Belinda Visser discussed the mechanics of the pedal stroke. She explained that it’s important to be mindful of what muscles need to fire in which pattern for an effective stroke, maximum power output and injury avoidance.
Referring the picture above, the part of the pedal stroke from 12 o’clock to 6 o’clock is known as the power phase. And 6 ‘clock back up to 12 o’clock is the recovery phase.
A: Starting at 12 o’clock, the hip extensors (“glutes”) will initiate the power phase. Belinda says many riders assume that the quadriceps are responsible for all the downward pressure on the pedals when the glutes actually supply the initial power for the movement. Strong glutes are crucial for stability, and to limit over-use of the quadsriceps during the power phase. “If your glutes are weak you may experience pain in other areas like your back because of strain on the hipflexors,” says Belinda.
B: At 3 o’clock, the knee extensors (quadriceps) take over from the glutes and contract until about the 5 o’clock position. These are very large powerful muscles which few of us struggle to engage but often overuse.
C: Around 4 o’clock, the ankle plantar flexors (the muscles responsible for pointing the toes downward) take over until 6 o’clock, ending the power phase. This is the area in the pedal stroke where you should imitate a sweeping motion as if scraping mud off the bottom of your shoe to create momentum.
D: Just after 6 o’clock, the ankle dorsiflexors (tibialis anterior) take over, beginning the recovery phase.
E: From 8 o’clock, the knee extensors (hamstrings) begin to contract.
F: And finally at 9 o’clock, the hip flexors (psoas, sartorius and rectis femoris) finish the recovery phase.
Belinda emphasised the importance of strong glutes. She said that most of the injuries she encounters in patients are as a result of this area being weak. “The glutius medius is a particularly important stabiliser that helps avoid bouncing on the bike, and unnecessary wasting of energy,” she said. Some good exercises to improve the strength of this area are “bridges” and “clams”.
Tips on bridges:
- Keep feet close together
- Eliminate use of the hamstrings by lifting toes slightly
- Alternate lifting legs
Tips on clams:
- Don’t lift your top leg too high – about 25 degrees is enough
- Engage your core
- Don’t roll backwards, keep hips stacked
So, next time you hit the spinning studio, the road or the trails try to think of the engagement cycle of the muscles used in the pedal stroke, especially the glutes. Engage and strengthen these muscles for a smoother more effective pedal stroke, not to mention a toned rear end!