Reducing Abnormal Muscle Coactivation After Stroke Using a Myoelectric-Computer Interface: A Pilot Study.

Area of Science:

• Neuroscience
• Rehabilitation Medicine
• Biomedical Engineering

Background:

• Stroke survivors often experience impaired movement due to abnormal muscle coactivation, hindering independent muscle activation.
• The exact cause of this abnormal coactivation remains unclear, but reducing it may enhance arm function.
• Myoelectric computer interfaces (MCI) offer a potential therapeutic approach by mapping electromyographic signals to control external devices, aiding in retraining muscle activation.

Purpose of the Study:

• To evaluate the efficacy of MCI training in reducing abnormal muscle coactivation in individuals with chronic stroke.
• To assess the impact of MCI training on upper-extremity motor function in stroke survivors.

Main Methods:

• The study involved 5 healthy participants and 5 stroke survivors with hemiparesis undergoing multiple MCI training sessions.
• Participants performed isometric muscle activations mapped to cursor movements, with MCI targeting specific muscle pairs to reduce coactivation.
• Upper-extremity function was quantified using the Fugl-Meyer Motor Assessment (FMA-UE).

Main Results:

• Both healthy individuals and stroke survivors successfully learned to decrease coactivation in targeted muscles through MCI training.
• Three out of five stroke survivors demonstrated a significant improvement in upper-extremity motor function, with an average FMA-UE increase of 3 points.
• MCI training proved effective in retraining muscle activation patterns.

Conclusions:

• Myoelectric computer interface training is a viable method for retraining muscle activation patterns in stroke survivors.
• The findings suggest that MCI can directly address abnormal muscle coactivation, potentially leading to functional improvements in arm movement post-stroke.