Neurophysiological insights into sit-to-stand post stroke.

Area of Science:

• Neuroscience
• Rehabilitation Medicine
• Biomechanics

Background:

• Stroke frequently impairs independent sit-to-stand ability, often leading to compensatory movement strategies.
• The neurophysiological underpinnings of sit-to-stand disability post-stroke and the specific brain injury impacts are not well understood.

Purpose of the Study:

• To investigate the neurophysiological mechanisms of sit-to-stand transfers in stroke survivors.
• To compare kinematic, muscle activation, and cortical activity patterns between stroke survivors and healthy adults during sit-to-stand transitions.

Main Methods:

• Ten stroke survivors and ten healthy adults performed sit-to-stand transitions.
• Three-dimensional kinematic data, electromyography (EMG) of key leg muscles, and electroencephalography (EEG) over the sensorimotor cortex were recorded.

Main Results:

• Stroke survivors were slower but used similar movement phases and temporal muscle activation patterns.
• Delayed peak activation was observed in the vastus lateralis and biceps femoris muscles in stroke survivors.
• Stroke survivors showed variable EEG patterns, reduced alpha/beta band synchronization, and increased interhemispheric asymmetry compared to controls.

Conclusions:

• While muscle activation timing is similar, peak activity is delayed in stroke survivors.
• EEG data reveals distinct cortical control differences, including variable event-related spectral perturbation (ERSP) patterns and hemispheric asymmetry.
• Findings suggest potential biomarkers for stroke recovery and the need for individualized brain-computer interface (BCI) training for sit-to-stand tasks.