Title: Adapting to sensorimotor delay in the control of standing balance
Supervisor: Dr. Jean-Sébastien Blouin
Committee members: Dr. Mark Carpenter, Dr. Lyndia Wu
Abstract:
The ability to stand upright is a crucial motor skill for humans. The sensing, transmission, and integration of sensory signals as well as force generation for balance involve delays that change during growth, aging, and certain pathologies. Although humans can learn to control their balance with artificially imposed delays, it remains unclear how they adjust their motor commands to accommodate the imposed delay. The purpose of my master thesis is to characterize how participants alter their body motion variability and lower limb activation and co-contraction as they learned to balance. I will impose a 250ms delay between the participant-generated motor commands and the resulting movement consequences using a balance robotic system. The novelty of the current study is that the robotic control of balance will be halted when participants reach the virtual limit (+4°/-2°), which allow me to replicate real-world condition when learning to stand. I will record the anteroposterior body sway and surface electromyography from the tibialis anterior, medial gastrocnemius, and soleus muscles bilaterally. It is of interest to quantify the body motion variability, muscle activation, and co-activation during the adaptation process and compare it to the quiet standing before and after the adaptation. This study could help to reveal how humans adjust their balance motor commands when learning to stand with imposed delay and may have implications for how humans adapt to changes in sensorimotor delay throughout their lifespan.