Initiating running barefoot: Effects on muscle activation and impact accelerations in habitually rearfoot shod runners

Abstract

Runners tend to shift from a rearfoot to a forefoot strike pattern when running barefoot. However, it is unclear how the first attempts at running barefoot affect habitually rearfoot shod runners. Due to the inconsistency of their recently adopted barefoot technique, a number of new barefoot-related running injuries are emerging among novice barefoot runners. The aim of this study was therefore to analyse the influence of three running conditions (natural barefoot [BF], barefoot with a forced rearfoot strike [BRS], and shod [SH]) on muscle activity and impact accelerations in habitually rearfoot shod runners. Twenty-two participants ran at 60% of their maximal aerobic speed while foot strike, tibial and head impact accelerations, and tibialis anterior (TA), peroneus longus (PL), gastrocnemius medialis (GM) and gastrocnemius lateralis (GL) muscle activity were registered. Only 68% of the runners adopted a non-rearfoot strike pattern during BF. Running BF led to a reduction of TA activity as well as to an increase of GL and GM activity compared to BRS and SH. Furthermore, BRS increased tibial peak acceleration, tibial magnitude and tibial acceleration rate compared to SH and BF. In conclusion, 32% of our runners showed a rearfoot strike pattern at the first attempts at running barefoot, which corresponds to a running style (BRS) that led to increased muscle activation and impact accelerations and thereby to a potentially higher risk of injury compared to running shod.

Keywords:

• Electromyography
• tibial shock
• shock attenuation
• foot strike

Acknowledgements

The authors would like to thank Ms. Marina Gil-Calvo and Mr. Vicent Ribas for their assistance throughout the study.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCiD

Angel Gabriel Lucas-Cuevas http://orcid.org/0000-0001-8646-9114

José Ignacio Priego Quesada http://orcid.org/0000-0002-0375-1454

Inma Aparicio http://orcid.org/0000-0003-3784-8489

Irene Jimenez http://orcid.org/0000-0001-7886-2602

Additional information

Funding

This work was supported by the Spanish Government (Ministerio de Educacin, Cultura y Deporte [grant FPU]; and Ministerio de Economa y Competitividad, Subdireccin General de Proyectos de Investigacin, Convocatoria Proyectos I+D Excelencia, Subprograma de Generacin de Conocimiento, 2013 [grant number DEP2013-48420-P]).