Free-living physical activity levels in children with cerebral palsy

Area of Science:

• Biomedical Engineering
• Pediatric Rehabilitation
• Movement Science

Background:

• Cerebral palsy (CP) is a common childhood motor disorder associated with reduced physical activity (PA) and increased health risks.
• Traditional PA assessment methods like accelerometers and self-reports have limitations.
• Electromyography (EMG) offers physiologically relevant insights into muscle activity during daily life.

Purpose of the Study:

• To assess and compare daily muscle activity using EMG in children with CP and typically developing (TD) peers during free-living conditions.
• To evaluate the utility of EMG as a complementary tool to accelerometry for PA monitoring in individuals with CP.

Main Methods:

• EMG sensors embedded in shorts and hip-worn accelerometers were used to record daily PA in 8 children with spastic CP (GMFCS I and III) and 6 TD children.
• EMG activity levels were normalized to the 6-minute walk test (6MWT).
• Inactivity, light, moderate, and vigorous PA were quantified using established accelerometry cut-offs and EMG amplitude categorization.

Main Results:

• No statistically significant differences in free-living EMG-measured inactivity or activity levels were found between the CP and TD groups.
• Accelerometry indicated greater inactivity time compared to EMG in both CP and TD groups.
• Few significant differences in muscle activity were observed within the CP group across legs, muscles, or GMFCS levels.

Conclusions:

• Free-living EMG monitoring did not reveal excessive daily muscle activity in individuals with CP compared to TD peers.
• EMG provides a more detailed assessment of daily muscle use, particularly for light physical activity, which may be underestimated by accelerometry.