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Published on: August 30, 2016
Effect of seat surface inclination on postural stability and forward reaching efficiency in children with spastic
Rong-Ju Cherng1, Hui-Chen Lin, Yun-Huei Ju
1Department of Physical Therapy, College of Medicine, National Cheng Kung University, Tainan, Taiwan. rjc47@mail.ncku.edu.tw
Insights
Seat surface inclination impacts postural stability and reaching in children. Anterior inclines improve function, while posterior inclines pose challenges, especially for children with cerebral palsy (CP).
Area of Science:
- Biomechanics
- Pediatrics
- Rehabilitation Science
Background:
- Postural stability and reaching are crucial for daily activities.
- Cerebral palsy (CP) often affects motor control, impacting these functions.
- Seat surface design can influence seated posture and movement.
Purpose of the Study:
- To investigate how seat surface inclination affects postural stability.
- To evaluate the impact on forward reaching efficiency in children.
- To compare effects in children with spastic cerebral palsy (CP) and typically developing (TD) children.
Main Methods:
- Children (10 with CP, 16 TD) performed static sitting and reaching tasks.
- Tasks were done on an adjustable stool at flat, anterior-inclined, and posterior-inclined positions.
- Measures included ground reaction force, center of pressure (COP) displacement, sway ratio, reaction time, and movement time.
Main Results:
- Seat inclination significantly affected postural stability and reaching efficiency in both groups.
- Anterior-inclined positions improved stability and efficiency compared to posterior positions.
- Children with CP showed greater medial/lateral sway (COP_ML) on posterior inclines than TD children.
Conclusions:
- Anterior seat inclinations enhance postural stability and reaching efficiency for children.
- Posterior seat inclinations present a greater postural challenge, particularly for children with CP.
- Adaptive seating strategies, like anterior inclination, may benefit children with motor impairments.
Abstract:
The purpose of this study was to examine the effect of seat surface inclination on postural stability and forward reaching efficiency in 10 children with spastic cerebral palsy (CP) and 16 typically developing (TD) children. The children performed a static sitting and a forward reaching task while sitting on a height- and inclination-adjustable stool at flat, three anterior-inclined, and three posterior-inclined positions. Postural stability was expressed as normalized (with body weight) peak vertical ground reaction force, center of pressure displacement in the anterior/posterior directions (COP_AP), in the medial/lateral directions (COP_ML), and sway ratio (COP_AP/COP_ML). Reaching efficiency was expressed as reaction time and movement time of arm reaching forward to a target. The results showed that seat inclination affected children's postural stability and the effects were comparable for CP and TD children in all measures except for COP_ML. Children with CP presented much larger COP_ML than TD children at the posterior-inclined positions relative to the flat and the anterior-inclined positions. Seat inclination affected reaching efficiency for both groups of children equally. Efficiency was better at the anterior positions than the posterior positions. Anterior-inclined positions improved postural stability and reaching efficiency. Posterior positions posed greater postural challenge and the challenge was tougher for children with CP.
