Objective Assessment of Cardiopostural Control and its Improvement after Yoga Training using Wii Balance Board and Heart Rate Variability in Young Girls with Flat Foot

Bipedalism in humans demanded robust postural control systems to maintain balance and equilibrium during variety of volitional activities. Adaptive learning is a key characteristic of these control systems. Postural control and balance are associated with autonomic changes trying to maintain cardiovascular homeostasis during postural imbalances, which are specifically important in conditions like flat foot. Yoga training could help such cases to achieve better postural balance and autonomic state. Young adolescent girls with flat foot were studied in comparison to normal girls and flat foot boys. Sixteen girls and 11 boys with flat foot were subjected to posturography on Wii Balance Board connected wirelessly to PowerLab 15T. Wireless heart rate belt was used to acquire RR intervals. Vrikshasana was chosen as the suitable asana for 4-week training. Displacement of center of pressure (COP) and heart rate variability was analyzed using LabChart pro software before and after yoga training. COP displacement in flat foot subjects is away from the center during erect stance and sway toward sides. Flat foot girls showed significant greater displacements and lesser correction after yoga compared to flat foot boys (P < 0.05). Flat foot girls also showed lesser recovery in LF% and RMSSD after 4-week yoga training. Studying the autonomic changes during voluntary postural imbalance on balance board provide real-time picture of internal state in flat foot individuals. The sympathetic dominance would account for preparedness and adaptation in postural control systems. This state improved with yoga training toward better cardiac vagal tone.