Experimental: Integrated Dual-task EMG Biofeedback Training (EMG-BF)

Participants will engage in EMG-BF for 30 minutes 3 times per week for 6 weeks for a total of 18 sessions. Our novel EMG Biofeedback training system can be adapted to a training objective by planning 3 to 5 movements and placing sensors over muscles that must be active when the user adheres to the correct movement form. For our training we use right or left torso shift with knee bend, and right or left hand opening, and place sensors over left and right vastus lateralis and left and right extensor digitorum superficialis muscles. Each movement corresponds to a specific videogame command. To introduce cognitive challenge, we randomly shuffle the game command assigned to each movement at the beginning of every session. This will require the user to choose the appropriate movement to trigger the intended game input while suppressing incorrect movements. We use the puzzle game, Tetris, which requires spatial reasoning and planning under increasingly tight time constraints.

Active Comparator: Traditional Balance Exercise Training (BAL-EX)

Participants will perform 7 balance exercises traditionally prescribed by physiotherapists. The first is a heel/toe square exercise where the trainee lifts their right toe and left heel, then their left toe and right heel, then both heels, then both toes. The 2nd exercise involves maintaining tandem stance while static, then moving the arms, then looking up and down, then looking left and right. The 3rd exercise is lateral stepping where the individual steps with one foot out to the side and then bring the foot back to the starting stance. The 4th exercise is a golfer's lift where the person slowly leans forward while extending one leg straight behind and touches the seat of a chair placed opposite. The 5th exercise is extended-duration single leg stands and exercises 6 and 7 are back and side leg raises, respectively. The exercise sequence will repeat until 30 minutes has expired. Sessions are repeated 3 times per week for 6 weeks, for 18 sessions.

Device: - Integrated Dual-task EMG Biofeedback Training (EMG-BF)

The intervention is an exercise training that is facilitated by feedback derived from electrical muscle activity measured through electromyography (EMG). An EMG Biofeedback software uses a machine learning algorithm to identify the desired movements and reinforce them by displaying feedback on a computer monitor in the form of videogame control. The EMG acquisition hardware must have at least 4 sensor channels and a sampling rate of >1KHz. Other than these specifications, any generic EMG amplifier can be used. The effect of the "device" is therefore primarily defined by the software. An in-depth description of the software and hardware systems is published in the cites study, "An EMG-Based Biofeedback System for Tailored Interventions Involving Distributed Muscles". In this trail is the Explore+ ExG amplifier which is sold by Mentalab.

Behavioral: - Traditional Balance Exercise Training (BAL-EX)

This intervention is a time-matched active comparator for the EMG-BF intervention. A sequence of seven traditional, balance exercises, taking 1-3 minutes each, is repeated for a total of 30 minutes on each of 18 sessions in the 6-week intervention period. The exercises are ones that challenge the coordination and strength of postural muscles in the presence of various vestibular stimuli. The specific exercises are described in the Arm description.