I hope I have made the case for very specific movement patterns, as the defining feature of the cycling activity; regardless of whether the individual is a recreational rider or an elite level sprinter.
It is highly doubtful that anyone on this earth is able to pedal perfect round circles. This is quite apparent from the “clock diagrams” and crank torque profiles. However, a separate issue is the perception of the movement which is “circular” if you ask elite level riders, and they take advantage of their Sidebend Hip Hike to more or less engage the full pedal stroke, some of it in the form of off loading. That SBHH enables the rider to optimize the reciprocal motion of the legs (to push/pull), and I am looking at a very specific outcome from the arms, torso, core and pelvis.
Instruct most amateur/recreational riders to perform the upstroke and they will not likely accomplish that task. This is not as straightforward as it sounds. What is required is instruction in the sidebend hike motion if they are to succeed. A close look at amateurs will reveal instability, especially up a minor hill (Col de Neighborhood), which manifests itself in various forms.