Pedaling Asymmetry Reflected by Bilateral EMG Complexity in Chronic Stroke

Area of Science:

• Neuroscience
• Rehabilitation Medicine
• Biomedical Engineering

Background:

• Stroke survivors often exhibit motor impairments, including pedaling asymmetry.
• Quantifying neuromuscular control in lower limbs is crucial for rehabilitation.
• Electromyogram (EMG) complexity offers a potential metric for assessing muscle activity.

Purpose of the Study:

• To investigate pedaling asymmetry in chronic stroke survivors using EMG complexity.
• To compare EMG complexity between stroke survivors and healthy individuals.
• To explore the relationship between EMG complexity and clinical motor function scores.

Main Methods:

• Recumbent pedaling tasks (passive and volitional) were performed by 15 chronic stroke survivors and 12 healthy controls.
• EMG signals from six bilateral lower limb muscles were recorded.
• Fuzzy approximate entropy (fApEn) was used to quantify EMG complexity.

Main Results:

• Stroke participants demonstrated significantly lower EMG complexity than healthy controls during pedaling (p = 0.002).
• Paretic limbs showed reduced EMG complexity compared to non-paretic limbs in stroke survivors during passive pedaling (p = 0.005).
• A significant correlation was found between paretic limb EMG complexity and clinical motor function scores during passive pedaling (p = 0.022, p = 0.028).

Conclusions:

• EMG complexity is a viable quantitative tool for assessing neuromuscular characteristics in lower limb dynamic movements in stroke survivors.
• Reduced EMG complexity in stroke survivors reflects impaired neuromuscular control.
• Paretic limb EMG complexity during passive pedaling may serve as a biomarker for stroke motor function status.