title: 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.
authors.affiliation: a Research Group in Sports Biomechanics (GIBD), Department of Physical Education and Sports , University of Valencia , Valencia , Spain.
authors.forename: Angel Gabriel
authors.initials: AG
authors.lastname: Lucas-Cuevas
authors.affiliation: a Research Group in Sports Biomechanics (GIBD), Department of Physical Education and Sports , University of Valencia , Valencia , Spain.|b Biophysics and Medical Physics Group , Department of Physiology , University of Valencia , Valencia , Spain.
authors.forename: José Ignacio
authors.initials: JI
authors.lastname: Priego Quesada
authors.affiliation: a Research Group in Sports Biomechanics (GIBD), Department of Physical Education and Sports , University of Valencia , Valencia , Spain.
authors.forename: José Vicente
authors.initials: JV
authors.lastname: Giménez
authors.affiliation: a Research Group in Sports Biomechanics (GIBD), Department of Physical Education and Sports , University of Valencia , Valencia , Spain.
authors.forename: Inma
authors.initials: I
authors.lastname: Aparicio
authors.affiliation: a Research Group in Sports Biomechanics (GIBD), Department of Physical Education and Sports , University of Valencia , Valencia , Spain.|b Biophysics and Medical Physics Group , Department of Physiology , University of Valencia , Valencia , Spain.
authors.forename: Irene
authors.initials: I
authors.lastname: Jimenez-Perez
authors.affiliation: a Research Group in Sports Biomechanics (GIBD), Department of Physical Education and Sports , University of Valencia , Valencia , Spain.
authors.forename: Pedro
authors.initials: P
authors.lastname: Pérez-Soriano
mesh_terms: D000054:Acceleration; D000328:Adult; D001696:Biomechanical Phenomena / Q000502:physiology; D005528:Foot / Q000502:physiology*; D006801:Humans; D007866:Leg / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D012420:Running / Q000502:physiology*; D055815:Young Adult
keywords: Electromyography; foot strike; shock attenuation; tibial shock