Knee extensor force control as a predictor of dynamic balance in healthy adults

Emily Mear; Valerie Gladwell; Jamie Pethick

doi:10.1016/j.gaitpost.2023.01.004

Knee extensor force control as a predictor of dynamic balance in healthy adults

Gait Posture. 2023 Feb:100:230-235. doi: 10.1016/j.gaitpost.2023.01.004. Epub 2023 Jan 10.

Authors

Emily Mear¹, Valerie Gladwell², Jamie Pethick³

Affiliations

¹ School of Sport, Rehabilitation and Exercise Sciences, University of Essex, Essex, UK.
² Institute of Health and Wellbeing, University of Suffolk, Suffolk, UK.
³ School of Sport, Rehabilitation and Exercise Sciences, University of Essex, Essex, UK. Electronic address: jp20193@essex.ac.uk.

PMID: 36638669
DOI: 10.1016/j.gaitpost.2023.01.004

Abstract

Background: Previous research has demonstrated that force control in various muscles of the lower limb (measured according to the magnitude of force fluctuations) explains significant variance in static balance. Given the dynamic nature of many functional activities and sports, assessment of balance and its determinants under dynamic conditions is of importance.

Research question: Does muscle force control explain significant variance in dynamic balance, as measured using the Y balance test (YBT)?

Methods: YBT performance and knee extensor muscle force control were measured in 28 healthy participants. The YBT involved stance on the right leg and attempting maximal reach with the left leg in the anterior, posteromedial, and posterolateral directions. Force control was assessed during isometric knee extension contractions of the right leg at 10%, 20% and 40% maximal voluntary contraction (MVC) and was quantified according to the magnitude (using the coefficient of variation [CV]), and the temporal structure (using sample entropy, SampEn; and detrended fluctuation analysis α), of force fluctuations.

Results: Significant correlations were observed for YBT anterior reach and muscle force CV (r = -0.44, P = 0.02) and SampEn (r = 0.47, P = 0.012) during contractions at 40% MVC. A subsequent regression model demonstrated that muscle force CV and SampEn at 40% MVC significantly explained 54% of variance in YBT anterior reach. Significant correlations were also observed for YBT posteromedial reach and MVC (r = 0.39, P = 0.043) and muscle force CV during contractions at 40% MVC (r = -0.51, P = 0.006). The regression model demonstrated that MVC and muscle force CV at 40% MVC significantly explained 53.9% of variance in YBT posteromedial reach.

Significance: These results are the first to indicate that a moderate amount of variance in dynamic balance can be explained by measures of isometric force control.

Keywords: Complexity; Entropy; Force; Fractal; Muscle; Steadiness.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adult
Humans
Isometric Contraction / physiology
Knee Joint / physiology
Knee* / physiology
Leg / physiology
Lower Extremity* / physiology
Muscle, Skeletal / physiology