Proceedings of The Physiological Society

Future Physiology (Leeds, UK) (2017) Proc Physiol Soc 39, PC19

Poster Communications

Preliminary investigations into the role of muscle contractile properties in single leg balance

K. Kolodziejczyk1, P. Francis1, C. Oddy1

1. Leeds Beckett University, Leeds, United Kingdom.

Concentric, eccentric and isometric strength of the hip musculature, the largest of which is gluteus maximus, are associated with single leg dynamic balance. Tensiomyography enables the assessment of the contractile properties of individual superficial muscles. Muscle displacement (Dm) is thought to be a surrogate measure of force and contraction time (Tc), estimated from the slope of the displacement-time curve, has been validated against fibre type. The HUMAC balance platform allows measurement of unipedal static balance via quantifying dispersion around the centre of pressure from a pre-set anatomical zero, over a 30-second period. The stability score generated is a ratio of the percentage of time the participant keeps their centre of pressure within the anatomical zero over the 30-second period. The aim of this study was to investigate the relationship between muscle contractile properties of the gluteus maximus, as measured by Tensiomyography, and single leg stability scores as measured by the HUMAC balance system in the non-dominant limb. Following University ethical approval, 9 healthy males (age: 30.1 ± 7.2 y; height: 180.0 ± 0.1 cm; mass: 75.4 ± 7.0 kg) and 8 healthy females (age: 23.1 ± 3.4 y; height: 166.0 ± 0.1 cm; mass: 59.0 ± 4.0 kg) participated in this study. There was no association between gluteus maximus maximal muscle Dm (r=0.413, P=0.099) or Tc (r=-0.383, P=0.129) and single leg stability scores. Data illustrated using X-Y scatter plots indicate a trend toward increasing Dm (Figure 1) and Tc being associated with higher levels of single stability but it is likely that this investigation was underpowered to detect an association. The results of this preliminary investigation suggest that there is no association between muscle contractile properties of the gluteus maximus and single leg stability scores. This work will be continued in an attempt to increase statistical power. Dm of individual muscles may not be associated with unipedal static balance in the way the whole muscle group strength has been shown to be.

Where applicable, experiments conform with Society ethical requirements