Reliability and validity of the Swaymeter for measuring the trunk control in children with spastic cerebral palsy

Abstract

Aims: To examine the reliability and validity of a simple device, the Swaymeter, for measuring trunk control in children with CP. Methods: Twenty children with spastic CP participated in this study. Trunk sway was measured while quietly sitting for 30s. Children lean forward or backward as far as possible for measuring dynamic balance range. Test–retest reliability was conducted. The concurrent and construct validity of the Swaymeter was assessed by comparison to the motion capture system and gross motor function measure (GMFM). Results: The reliability of the Swaymeter was moderate to excellent in measuring trunk sway and dynamic balance range (ICCs = 0.696–0.948). Concurrent validity showed good results (r = 0.818–0.997) and construct validity of dynamic balance in anterior direction showed moderate to high correlation with the GMFM (r = 0.599–0.849). Conclusion: Assessment of trunk control in a sitting position using the Swaymeter in this study was valid and reliable in children with CP.