Standing on unstable surface challenges postural control of tracking tasks and modulates neuromuscular adjustments specific to task complexity.

摘要: Understanding the modulations of motor control in presence perturbations task conditions varying complexity is a key element towards design effective perturbation-based balance exercise programs. In this study we investigated effect mechanical perturbations, induced by an unstable surface, on muscle activation and visuo-postural coupling, when actively tracking target motion cues different complexity. Four postural tasks following visual oscillating (periodic-sinusoidal vs. chaotic-Lorenz) surface (stable-floor unstable-foam) were performed. The electromyographic activity main plantarflexor dorsiflexor muscles was captured. coupling between sway assessed through spectral analysis system's local dynamic stability short-term maximum Lyapunov exponent. We found that external increased instability deteriorated visuo-motor coupling. Visuo-motor deterioration greater for chaotic target, implying depends There modulation neuromotor system amplification coactivation to compensate surface-related ensure robust control. Our findings provide evidence that, induces specific while controlling posture.