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Electromyographic investigation of extensor activity in cerebral-palsied children in different seating positions
Insights
This study found that seating position significantly affects low-back extensor muscle activity in children with spastic cerebral palsy. The least muscle activity occurred with a 0-degree seat elevation and 75-degree backrest angle.
Area of Science:
- Biomedical Engineering
- Rehabilitation Science
- Pediatric Neurology
Background:
- Children with spastic cerebral palsy often exhibit altered muscle tone and postural control.
- Seating interventions are crucial for managing posture and comfort in individuals with cerebral palsy.
- Understanding muscle activity in different seating positions can inform ergonomic design and therapeutic strategies.
Purpose of the Study:
- To investigate the impact of varying seating positions on the tonic myoelectric activity of low-back extensors in children with spastic cerebral palsy.
- To identify the specific seating configuration that minimizes extensor muscle activity.
Main Methods:
- Electromyographic (EMG) signals from lumbar erector spinae muscles were recorded using surface electrodes.
- Participants were positioned in seven different combinations of backrest inclinations (75°, 90°, 105°, 120°) and seat surface elevations (0°, 15°).
- Off-line analysis quantified action potential counts per second to assess muscle electrical activity.
Main Results:
- Significant differences in low-back extensor muscle activity were observed across the assessed seating positions.
- The lowest electrical activity was recorded when the seat surface elevation was 0 degrees and the backrest inclination was 75 degrees.
Conclusions:
- Seating position is a critical factor influencing low-back extensor muscle engagement in spastic cerebral palsy.
- A specific seating configuration (0° seat elevation, 75° backrest inclination) may reduce muscle strain and improve postural management.
Abstract:
This study was designed to determine whether tonic myoelectric activity of low-back extensors of spastic cerebral-palsied children changed in response to changes in seating position, and if so, which position was coincident with the least extensor activity. Using two pairs of surface electrodes, the electrical activity of the lumbar erector spinae muscles was monitored in seven combinations of backrest inclinations (75 degrees, 90 degrees, 105 degrees and 120 degrees) and seat surface elevations (0 degrees and 15 degrees). Off-line analysis of action potential counts per second of recorded electromyographic signals showed that electrical activity was least when the seat surface elevation was 0 degrees and the backrest inclination 75 degrees. The results showed that differences existed in the activity of the low-back extensors in the seating positions that were assessed.