The Pedal Stroke

The current definition is equipment centric, a rather artificial construct. The assumption that the region from the “top” to the “bottom” of the pedal stroke somehow corresponds to limb extension is incorrect, this is applicable only when the head of the femur is directly above the bottom bracket.

Whether we are talking about the sidebend hip hike or the trunk pelvic roll (movement patterns in cycling) it is far more useful to allow the movement of the torso and pelvis define the application of “moments” to the crankarm. Therefore, there would be greater value to subdivide the pedal stroke in a more fluid set of quadrants that reflect the movement of the athlete (as well as the legs). If so, then only one quadrant has been accounted for, leaving the other three to be managed by the movement pattern.

Muscle Strategy in Cycling

Do the observations from running apply to cycling? Take a look at this publication, the abstract can be found through PubMed.

J Exp Biol. 2012 Jun 1;215(Pt 11):1944-56. doi: 10.1242/jeb.064527.

Muscular strategy shift in human running: dependence of running speed on hip and ankle muscle performance. Dorn TW, Schache AG, Pandy MG. Department of Mechanical Engineering, University of Melbourne, Melbourne, Victoria 3010, Australia.

If they do apply, then a tempo pace may have greater reliance on the leg and thigh musculature for propulsion. While the stride length equivalent is not modifiable in cycling, the frequency is. The sprint would require a vigorous acceleration of the hip and knee joints during the upstroke and forward sweep, analogous to the swing phase in running. This would involve increased recruitment of the iliopsoas, gluteus maximus and hamstrings.