The magnitude of the effect of calf muscles fatigue on postural control during bipedal quiet standing with vision depends on the eye-visual target distance

TL;DR

This study investigates how calf muscle fatigue affects postural control during quiet standing and how this effect varies with the distance of the visual target, highlighting the importance of visual information quality in balance regulation.

Contribution

It demonstrates that the impact of calf muscle fatigue on postural stability depends on the visual target distance, emphasizing the role of visual information in sensory reweighting during balance control.

Findings

Fatigue increased postural sway in no vision and 4m vision conditions.

At 1m vision, fatigue's destabilizing effect was reduced along the anterior-posterior axis.

Visual target distance influences the effectiveness of visual cues in compensating for muscle fatigue.

Abstract

The purpose of the present experiment was to investigate whether, with vision, the magnitude of the effect of calf muscles fatigue on postural control during bipedal quiet standing depends on the eye-visual target distance. Twelve young university students were asked to stand upright as immobile as possible in three visual conditions (No vision, Vision 1m and Vision 4m) executed in two conditions of No fatigue and Fatigue of the calf muscles. Centre of foot pressure displacements were recorded using a force platform. Similar increased variances of the centre of foot pressure displacements were observed in the fatigue relative to the No fatigue condition for both the No vision and Vision 4m conditions. Interestingly, in the vision 1m condition, fatigue yielded: (1) a similar increased variance of the centre of foot pressure displacements to those observed in the No vision and Vision 4m conditions along the medio-lateral axis and (2) a weaker destabilising effect relative to the No vision and Vision 4m conditions along the antero-posterior axis. These results evidence that the ability to use visual information for postural control during bipedal quiet standing following calf muscles fatigue is dependent on the eye-visual target distance. More largely, in the context of the multisensory control of balance, the present findings suggest that the efficiency of the sensory reweighting of visual sensory cues as the neuro-muscular constraints acting on the subject change is critically linked with the quality of the information the visual system obtains.