Modulation of Lower-Limb Muscle Activity in Maintaining Unipedal Balance According to Surface Stability, Sway Direction, and Leg Dominance

Abstract

Determining temporal similarity in shape between electromyographic (EMG) and center-of-pressure (COP) signals reflects neuromuscular control in terms of which relevant muscles are involved in maintaining balance. The current study aimed to investigate a cross-correlation between seven lower-limb EMG activities and COP displacements, simultaneously measured in 25 young adults unipedally balancing on stable and multiaxial-unstable surfaces. The effect of surface stability, sway direction, and leg dominance was then tested on two EMG–COP correlation levels: individual muscles and groups (patterns) of multi-muscles involved in postural sway, as determined by principal component analysis (PCA). The results show that two factors demonstrate their effects only at the level of individual muscles: sway direction (p ≤ 0.003) and leg dominance (p = 0.003). Specifically, the semitendinosus, tibialis anterior, peroneus longus, and soleus correlate more with the mediolateral postural sway than with the anteroposterior postural sway, except for the gastrocnemius medialis. Additionally, balancing on the non-dominant leg shows a lower correlation between the semitendinosus and postural sway than on the dominant leg. The current findings suggest that when achieving unipedal equilibrium, the postural control system may be constrained the most in the specific muscles of the least steady conditions, e.g., the frontal plane and non-preferred leg.

Trend change analysis in the assessment of body balance during posture adjustment in reaction to anterior-posterior ground perturbation

“…Taking into account the fact that COP is a reaction to COM movement, registered, in this article, changes in TCI_dS could result from the change in the COM movement. However, taking into consideration the fact that the COP movements are identified as a resultant force acting the ground [ 30 , 31 ], it could also indicate the changed patterns of the work of muscles preparing for oncoming disruption, which is often observed in such types of tests [ 8 , 24 , 32 , 33 ]. However, the statement requires additional research.It should be noted that the lack of change in the number of trend changes could also result from the very short measurement time precluding the detection of slight differences.…”

The Impact of Aerobic Dance Intervention on Postural Balance in Children: A Randomized Controlled Trial

“…Investigating the impact of aerobic dance on postural balance in children, particularly under various sensory manipulations, such as stances, eye conditions, and surface types, is of significant importance. Bipedal and unipedal stances are fundamental in evaluating postural balance, with unipedal stance imposing greater postural demands and requiring enhanced neuromuscular control [39]. Moreover, open-and closed-eyes conditions are essential in examining the influence of visual feedback on postural balance, with open open-eyes (OE) condition allowing individuals to use visual cues to maintain balance and closed-eyes (CE) condition challenging individuals to rely more on proprioceptive and vestibular inputs [40,41].…”