# EMG-Controlled Game to Retrain Upper Extremity Muscle Activation Patterns Following Stroke

> **NIH VA I01** · RALPH H JOHNSON VA MEDICAL CENTER · 2024 · —

## Abstract

An estimated 15,000 Veterans suffer a stroke per year, more than 75% of whom have persistent hand
impairment even after a full course of rehabilitation that significantly diminishes their independence.
Fundamentally, post-stroke upper limb impairments arise from altered muscle activation patterns. Thus, direct
training of muscle activation patterns holds promise. Unfortunately, altered muscle activation patterns are not
fully addressed in current rehabilitation. Previous efforts have been limited to training a single pair of muscles,
failing to address aberrant intersegmental coupling. To address this gap, a novel EMG-controlled game system
has been developed: EMG signals are mapped to the 2-dimensional motion of a cursor on a computer screen
to play games. In a preliminary study, the target EMG patterns were derived from 4 nonparetic distal upper
limb muscle EMGs, while games were played using 4 paretic distal upper limb muscle EMGs mapped to the
target patterns, thereby promoting use of the nonparetic muscle activation patterns in the paretic limb. Twenty
stroke survivors improved upper limb function assessed by the Wolf Motor Function Test Functional Abilities
(WMFT FA) significantly after 9 game sessions. Objective: To expand the capacity of the EMG-controlled
game system and integrate it into a full therapy paradigm. Aim 1: Improve the system. Muscle activation
patterns will be characterized with nonnegative EMG amplitudes to make the game control more intuitive. The
number of EMG input channels will be increased to include both proximal and distal upper limb muscles for
intersegmental training. More games will be created for engagement. Feasibility of the improved system will be
evaluated with neurologically intact Veterans. Aims 2-3 will evaluate the system with Veteran stroke survivors.
Veterans stroke survivors will be randomly assigned to one of two groups. The treatment group will receive 9
EMG game sessions and 9 task practice therapy sessions in an alternating order. The control group will
receive 18 task practice therapy sessions. Evaluation will occur at baseline, post, and 1-month follow-up. Aim
2: Determine the effect of the EMG game system plus task practice therapy on upper limb function. Hypothesis:
The group training with the EMG games in conjunction with task practice therapy will improve their upper limb
function assessed by WMFT FA (primary) more than the group training with dose-matched task practice therapy
only. Aim 3: Determine the neuromechanical changes associated with training with the EMG-controlled games.
Hypothesis: The paretic muscle activation patterns will assimilate to the nonparetic pattern only for the treatment
group. The similarity will be quantified by computing the angle between the hyperplane defined by the paretic EMG
patterns and the plane defined by the nonparetic EMG patterns. Impact: This research will address the current
treatment gap by developing/evaluating a novel EMG-controlled game system to...

## Key facts

- **NIH application ID:** 10795014
- **Project number:** 5I01RX004523-02
- **Recipient organization:** RALPH H JOHNSON VA MEDICAL CENTER
- **Principal Investigator:** Na Jin Seo
- **Activity code:** I01 (R01, R21, SBIR, etc.)
- **Funding institute:** VA
- **Fiscal year:** 2024
- **Award amount:** —
- **Award type:** 5
- **Project period:** 2023-04-01 → 2027-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10795014

## Citation

> US National Institutes of Health, RePORTER application 10795014, EMG-Controlled Game to Retrain Upper Extremity Muscle Activation Patterns Following Stroke (5I01RX004523-02). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10795014. Licensed CC0.

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