Q: One correlation I have noticed that is pretty consistent across all of my runs is the correlation between pronation velocity and pronation excursion…Overall my RS numbers were pretty symmetrical b/w my right and left foot (which is something that I’ve been thinking about lately – whether or not it’s beneficial to strive for symmetrical biomechanics b/w my left and right side).? -Paul

A: There is indeed a strong relationship between maximum pronation velocity and pronation excursion, from both algorithm and foot-movement points of view. If you’re somebody who pronates in 50msec consistently, with reasonably low (<800deg/sec) pronation velocities, then you’ll see a very strong correlation between pronation velocity and pronation excursion. As the pronation velocities get higher (and the pronation times vary), the correlations can become less strong. In terms of symmetry, don’t be too concerned with striving for “perfect” symmetry. No one has exactly the same movement patterns on both R and L sides. However, if you have chronic injuries that tend to appear more on one side than the other it is useful to try and understand what the differences are and what might be causing them. – RS