One-Leg Standing: Right and Left Balance COP and EMG Analyses

Manual asymmetries in motor control have been studied for more than 120 years, with the bulk of this work focusing on unimanual control of upper limb movements. Given that the global population is aging, and that gait and balance disorders in this population are common causes of falls, it is critical to understand control mechanisms underlying balance. To this end, the current study investigates lateralization control mechanisms underlying one leg balance using the mean distribution and variability in center of pressure (COP) in 109 right-hand dominant individuals. Participants stood on a force platform with either the left leg, right leg, or both legs under two visual conditions (eyes open and closed). Electromyography (EMG) was recorded from four lower leg muscles (tibialis anterior, peroneus longus, soleus, and the medial head of the gastrocnemius) in 15 participants. Preliminary data analysis indicates that center of pressure (COP) distribution and variability and overall muscle activity is higher in eyes-closed conditions. In addition, asymmetries in postural stability control were observed, with higher COP variability in the single left leg than right leg in both anterior-posterior and medial-lateral directions. higher EMG activity during left leg standing for both visual conditions. In future work, we will examine potential differences in the lateralization of postural control in aging populations and in populations with impaired postural control.