Hot on the heels of the prospective study I just reviewed on injury rates between barefoot and traditionally shod runners that showed that there really weren’t any differences we have a publication showing that here were no differences between different foot strike patterns as well. I have already discussed this study as it was first presented at the ACSM conference last year. At that time a number of critics did not want to give any weight to this study as it was only a conference abstract and not a full peer reviewed publication. It is now a full peer reviewed publication:
Characterization of Foot-Strike Patterns: Lack of an Association With Injuries or Performance in Soldiers
MAJ Bradley J. Warr; Rebecca E. Fellin; Shane G. Sauer; LTC Donald L. Goss; Peter N. Frykman; Joseph F. Seay
Military Medicine; Volume 180 Issue 7, July 2015, pp. 830-834
Objectives: Characterize the distribution of foot-strike (FS) patterns in U.S. Army Soldiers and determine if FS patterns are related to self-reported running injuries and performance.
Methods: 341 male Soldiers from a U.S. Army Combined Arms Battalion ran at their training pace for 100 meters, and FSs were recorded in the sagittal plane. Participants also completed a survey related to training habits, injury history, and run times. Two researchers classified FS patterns as heel strike (HS) or nonheel strike (NHS, combination of midfoot strike and forefoot strike patterns). Two clinicians classified the musculoskeletal injuries as acute or overuse. The relationship of FS type with two-mile run time and running-related injury was analyzed (p ≤ 0.05).
Results: The Soldiers predominately landed with an HS (87%) and only 13% were characterized as NHS. Running-related injury was similar between HS (50.3%) and NHS (55.6%) patterns (p = 0.51). There was no difference (p = 0.14) between overuse injury rates between an HS pattern (31.8%) and an NHS pattern (31.0%). Two-mile run times were also similar, with both groups averaging 14:48 minutes.
Conclusion: Soldiers were mostly heel strikers (87%) in this U.S. Army Combined Arms Battalion. Neither FS pattern was advantageous for increased performance or decreased incidence of running-related injury.
The strength of this study was that is it prospective and a weakness is that it is a cohort study (ie not prospectively randomized to groups). A weakness of the cohort type studies is the difference in baseline characteristics (for eg, in yesterdays post, the shod group did almost twice as much mileage as the barefoot group). In the above study the groups were more homogeneous (due to being in the army!) which is a strength of the study. This is also a weakness of the study in that how applicable are the running injuries that soldiers get compared to the wider running community? Soldiers do other physical activities, specifically load carriage and asymmetry due to rifle carriage in addition to the running that they do.
This was a good study, methodologically sound and I have no issues about with it. The only issue is the extrapolation of its findings to a wider non-military populations. I guess if you are a midfoot/forefoot fan boy, then you are not going to want to accept the results for that reason. Me? This study fits in with the preponderance of the other studies that show that there are no differences in injury rates between different foot strike patterns.
As always, I go where the evidence takes me until convinced otherwise …. and I still see no evidence that there is anything wrong with heel striking.
Warr BJ, Fellin RE, Sauer SG, Goss DL, Frykman PN, & Seay JF (2015). Characterization of Foot-Strike Patterns: Lack of an Association With Injuries or Performance in Soldiers. Military medicine, 180 (7), 830-4 PMID: 26126256