Effects of optimal tactile feedback in balancing tasks: A pilot study

In this study, we employ optimal control and tactile feedback to teach subjects how to balance a simulated inverted pendulum. The output of a Linear Quadratic Regulator (LQR) was converted to a vibratory teacher-signal and was provided as additional somatosensory feedback to the subjects. The LQR approach is consistent with an energy-saving strategy commonly observed during human motor learning. Our rationale for using the inverted pendulum as a criterion task is that this balance system requires the brain to solve many of the same problems encountered in simple tasks of daily living like transporting a glass of water to the mouth. Experimental results indicate that subjects who trained with the teacher-signal, performed significantly better than subjects who trained only with visual feedback. This result is promising and can be applied, among other fields, in rehabilitation to compensate for lost or compromised proprioception, commonly observed in stroke survivors.