Dynamic Neuromuscular Control of the Lower Limbs in Response to Unexpected Single-Planar versus Multi-Planar Support Perturbations in Young, Active Adults.

Bart Malfait,Aijse De Vries,Annemie Smeets,Jos Vanrenterghem,Mark A Robinson,Sabine Verschueren,Filip Staes,Malcolm Hawken,Andrea Macaluso

doi:10.1371/journal.pone.0133147

Bart Malfait, Aijse De Vries + Show 7 more

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https://doi.org/10.1371/journal.pone.0133147

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Journal: PloS one	Publication Date: Jul 29, 2015
Citations: 7	License type: CC BY 4.0

Affiliation: KU Leuven, Liverpool John Moores University

Abstract

PurposeAn anterior cruciate ligament (ACL) injury involves a multi-planar injury mechanism. Nevertheless, unexpected multi-planar perturbations have not been used to screen athletes in the context of ACL injury prevention yet could reveal those more at risk. The objective of this study was to compare neuromuscular responses to multi-planar (MPP) and single-planar perturbations (SPP) during a stepping-down task. These results might serve as a basis for future implementation of external perturbations in ACL injury screening programs.MethodsThirteen young adults performed a single leg stepping-down task in eight conditions (four MPP and four SPP with a specified amplitude and velocity). The amplitudes of vastus lateralis (VL), vastus medialis (VM), hamstrings lateralis (HL), hamstrings medialis (HM) EMG activity, medio-lateral and anterior-posterior centre of mass (COM) displacements, the peak knee flexion and abduction angles were compared between conditions using an one-way ANOVA. Number of stepping responses were monitored during all conditions.ResultsSignificantly greater muscle activity levels were found in response to the more challenging MPP and SPP compared to the less challenging conditions (p < 0.05). No differences in neuromuscular activity were found between the MPP conditions and their equivalents in the SPP. Eighteen stepping responses were monitored in the SPP versus nine in the MPP indicating that the overall neuromuscular control was even more challenged during the SPP which was supported by greater COM displacements in the SPP.ConclusionThe more intense MPP and SPP evoked different neuromuscular responses resulting in greater muscle activity levels compared to small perturbations. Based on the results of COM displacements and based on the amount of stepping responses, dynamic neuromuscular control of the knee joint appeared less challenged during the MPP. Therefore, future work should investigate extensively if other neuromuscular differences (i.e. co-activation patterns and kinetics) exist between MPP and SPP. In addition, future work should examine the influence on the neuromuscular control of the magnitude of the perturbations and the magnitude of stepping height and stepping distance.

Highlights

Anterior cruciate ligament (ACL) injuries are very common during sports activities in the young, active population (16–40 years); affecting approximately 250,000 people per year in the US [1]
Greater muscle activity levels were found in response to the more challenging multi-planar perturbations (MPP) and single-planar perturbations (SPP) compared to the less challenging conditions (p < 0.05)
Eighteen stepping responses were monitored in the SPP versus nine in the MPP indicating that the overall neuromuscular control was even more challenged during the SPP which was supported by greater centre of mass (COM) displacements in the SPP

Summary

Introduction

Anterior cruciate ligament (ACL) injuries are very common during sports activities in the young, active population (16–40 years); affecting approximately 250,000 people per year in the US [1]. Non-contact ACL injuries occur mostly in a multi-planar way during high-velocity deceleration, pivoting or landing tasks [3] that often lead to high external knee joint loads. During the performance of sports activities, ground reaction forces can exceed 5–6 times the athlete’s bodyweight [4]. These high external knee joint loads have to be counteracted by adequate neuromuscular control strategies to protect the joint against excessive tibio-femoral movements and thereby prevent joint damage. While previous work has shown that there is a relation between an ACL injury and dynamic knee joint stability [7,8], the causality between an ACL injury and an altered neuromuscular control remains unclear. Zebis et al [12] showed that a large difference in muscular activity (amplitude) between the vastus lateralis (VL) and hamstring medialis (HM) during the preparatory phase (10 ms before initial contact) of a side cutting manoeuver might have a predictive value for ACL injury risk determination

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