One of the interesting aspects of the CompuTrainer is the SpinScan. I’m not sure quite how it’s done, but the system measures the torque applied to the pedals at each point in the compass. The visual display gives you an idea of the efficiency of your pedal stroke – an ideal pedal stroke would show a perfectly level distribution of power at all points of rotation (this is how Titanium Man rides).
This is a SpinScan from the start of Mary’s ride this morning. The blue bars are the downstroke, green is across the bottom, yellow is the upstroke, and red is pushing across the top of the pedals.
As you can see, Mary is very right-leg dominant. Her left leg is slightly shorter than her right, the result of being in a body cast for 6 months at the age of 4. (She broke her leg getting out of a hammock when her mother called out that there was a bowl of cherries in the kitchen.)
This next scan shows the effect of pushing hard across the top of the pedals (the red bars have come up). You can feel the different muscle groups when you do this – the hip flexors aren’t accustomed to these demands.
Finally, here she’s going all out for a finish at the bottom of a hill. She’s pushing 164 watts with a good distribution of power.