Actual data on foot strike patterns
The debate rages on about how your foot should land when you’re running — but we still know remarkably little about how people’s feet are currently landing in the real world, outside of biomechanics laboratories. Pete Larson (of Runblogger fame) has a new paper in the Journal of Sports Sciences that offers some interesting data. It’s a very straightforward study: he (and his undergrad researchers) hung out at the 10K and 32K marks of the 2009 Manchester City Marathon with a high-speed camera, and filmed the runners going past. Then they went back and classified the foot strikes into three categories as illustrated here:
At the 10K mark, he got data for 936 runners who were doing either the half or full marathon. The results:
- rearfoot: 88.9%
- midfoot: 3.4%
- forefoot: 1.8%
- asymmetrical (i.e. different with right and left foot): 5.9%
It’s worth noting that virtually none of the runners were barefoot or wearing Vibrams — this was 2009, before the frenzy really started. Larson collected more data this year, so it will be interesting to see what (if anything) changes when that data is analyzed.
At the 32K mark, it was just marathoners, and Larson was able to positively identify 286 runners at both the 10K and 32K marks. Of these runners, 87.8% were rearfoot striking at 10K, and 93.0% were rearfoot striking at 32K. Basically, some of the runners who weren’t rearfoot striking initially got tired and settled into a rearfoot gait. There were no forefoot strikers left at 32K. To me, this is the most interesting avenue for further research: can people who switch to a forefoot strike maintain it all the way through a marathon? Do you have to grow up barefoot to develop that strength, or can it be acquired in a few years?
One last point: no significant relationship between race times and foot strike (though the number of non-rearfoot strikers was so small that any relationship would have been hard to find). Anyway, great to see some hard data, and I’m sure we’ll see a lot more like this in the years to come.