Fatigue-Induced Inter-Limb Asymmetries in Strength of the Hip Stabilizers, Postural Control and Gait Following a Unilateral Countermovement Vertical Jump Protocol.

Ioannis Konstantopoulos,Vasileios Chatziilias,Ioannis Kafetzakis,Dimitris Mandalidis

doi:10.3390/sports9030033

Ioannis Konstantopoulos, Vasileios Chatziilias + Show 2 more

Open Access

https://doi.org/10.3390/sports9030033

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Journal: Sports	Publication Date: Feb 27, 2021
Citations: 3	License type: CC BY 4.0

Affiliation: National and Kapodistrian University of Athens

Abstract

It is generally accepted that neuromuscular overload and fatigue of one lower limb can affect the functional ability of the ipsilateral limb, and possibly the contralateral limb, increasing the likelihood of injury. The purpose of the current study was to examine the effect of a unilateral countermovement vertical jump (UCVJ) fatigue protocol on the neuromuscular function of the ipsilateral as well as the contralateral lower limb. The isometric strength of the hip stabilizers, postural control via posturographic analysis during the Y-Balance-Test (YBT), and the stance-phase-of-gait were assessed in 24 healthy physical active males and females before and after execution of a UCVJ fatigue protocol. The fatigue protocol included 5 sets of 20 maximum UCVJs performed on the supportive leg, with a 30-s break between sets. Following a 16.8% decline in vertical jump performance and an associated 2.3-fold increase in perceived exertion, our findings revealed significant post-fatigue inter-limb differences regarding postural control. The post-fatigue inter-limb differences regarding the isometric strength of the hip stabilizers and the stance-phase-of-gait parameters were not significant. Our findings showed that a 100 UCVJs session is likely to induce significant inter-limb differences in postural control, possibly increasing the risk of lower limb injury.

Highlights

The unilateral vertical jump training protocol yielded a significant reduction in the average vertical jump height (−16.9%, p < 0.001, η2 = 0.46) and the flight time (−8.8%, p < 0.001, η2 = 0.39)
The results of this study showed that unilateral lower limb fatigue by means of 100 vertical jumps may increase inter-limb asymmetry, at least in terms of postural control
With inter-limb asymmetries being considered a predisposing factor for sports injuries, our findings show that such differences can emerge due to functional muscle fatigue, partly confirming the higher risk of injury that exists at the end of a game/training session where a similar number of jumps are expected to have taken place

Summary

Introduction

Inter-limb asymmetries in sports, i.e., the differences between the limbs in terms of their functional ability (e.g., flexibility, range of motion strength and motor control) due to the predominant use of one limb over the other [1], are common in athletes involved in unilateral as well as bilateral sporting activities [1,2,3] Such asymmetries have received a lot of attention from sport coaches and clinicians as they have been associated with both a decrease in athletic performance [4,5] and an increase in the risk of non-contact injuries [6]. Despite the growing interest in this issue, the number of studies conducted is limited and the available findings remain unclear

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