Previously I posted about a descriptive study on the Foot strike pattern and performance in a marathon; now we have this one for a 50km trail race:
The relationship of foot strike pattern, shoe type, and performance in a 50-km trail race
Kasmer, Mark E.; Liu, Xue-cheng; Roberts, Kyle G.; Valadao, Jason M.
Journal of Strength & Conditioning Research: 15 July 2013; doi: 10.1519/JSC.0b013e3182a20ed4
Recent “in-race” studies have observed the foot strike patterns of runners in traditional road marathon races. However, similar studies have not been conducted for trail runners, which have been estimated to account for 11% of all runners. The purpose of this study was to: 1) determine the rear-foot strike (RFS) prevalence in a 50 km trail race and compare with traditional road marathon races; 2) determine if there is a relationship between foot strike and sex in a 50 km trail race; and 3) determine if there is a relationship between foot strike, shoe type, and performance in a 50 km trail race. 165 runners were videotaped at the 8.1 km mark of the 2012 Ice Age Trail 50 km race. Foot strike analysis revealed RFS prevalence of 85.1%, less than previously reported in traditional road marathon races. There was no relationship found between sex and foot strike (p=0.60). A significant effect of shoe type on foot strike (RFS was less common among runners in minimalist shoes, p<0.01) and performance (faster runners were more likely to be wearing minimalist shoes, p<0.01) was observed; however, no association between foot strike and performance was observed (p=0.83). This study suggests that most trail runners, albeit less than road runners, prefer a RFS pattern, which is accompanied by biomechanical consequences unique from a non-RFS pattern and therefore, likely carries a unique injury profile. In addition, the findings in this study suggest that minimalist shoes may represent a reasonable training modification to improve performance.
The main finding of this descriptive study was that 85.1% of the runners were heel strikers; compared to the figures of 94% in a marathon for this study and 89% from this study. They found no correlation between foot strike pattern and performance; though faster runners were more likely to be wearing minimalist shoes.
Honestly, there is not a lot more I can say about this study, than what I did say in the comments on a previous study, so might as well refer you to that: Foot strike pattern and performance in a marathon.
As always, I go where the evidence takes me, and that tells me that most runners still prefer to run with a heel strike.
Kasmer, Mark E, Liu, Xue-cheng, Roberts, Kyle G., & Valadao, Jason M. (2013). The relationship of foot strike pattern, shoe type, and performance in a 50-km trail race Journal of Strength & Conditioning Research: DOI: 10.1519/JSC.0b013e3182a20ed4