Loading rate, peak vertical GRF and injury: Why are we still having this discussion?

A very recent paper has piqued my interest and revived my need to have a discussion about how much we read into kinematic data.

The paper by Joe Hamill and Allison Gruber:

Is changing footstrike pattern beneficial to runners?
Joseph Hamill & Allison H. Gruber,
Journal of Sport and Health Science; 28 February 2017

A very timely and an excellent read. Not the least, to really underline how futile the discussion about vertical ground reaction force peaks and loading is, especially in the context of injury and cushioning in running shoes.

Now I blame Daniel Lieberman for a lot of this, because he was the one who popularized the notion that changing a runner's footfall pattern from an ”un-natural” rearfoot strike to a ”more natural” forefoot strike, whether unshod or shod, may be a propitious way to improve performance and possibly reduce running-related injuries. [5] [6] [7] And he based this on the supposition that, by analyzing the vertical ground reaction force (vGRF) data for a heel striker vs a forefoot striker, the “impact peak” would magically disappear, therefore no impact would occur, and the forefoot striker would be less prone to injury (all of this feeding back into the barefoot model which controversially assumes all barefoot runners must be forefoot stikers).

Simon Bartold
Director of Bartold Clinical