The validity and reliability of the Swaymeter for postural sway measurement in typically developing children aged...

The Swaymeter is a simple devicefor measuring postural sway. It consists of a 40-cm-long rod with a vertically mounted pen at the end of the rod that measures the displacement of the body at waist level.

This device could be an effective tool for measuring postural sway in children. However, the validity and reliability of the Swaymeter in children has not been evaluated. In this study, we aimed to evaluate the validity and reliability of the Swaymeter in typically developing children aged 7-12 years.

The Swaymeter procedure was randomly measured in quiet bipedal stance under 4 conditions: eyes open and eyes closed on the floor, eyes open and eyes closed on foam, 30 s were performed in each condition. There were 15 children participated in the validity study. The postural sway was measured concurrently with the motion capture system with two reflective markers on the top of the pen and 12^th thoracic vertebra level in three trials with four testing conditions. Additionally, 36 children participated in test-retest reliability. Three measurements were performed on the same day and one week later.

Swaymeter had a moderate to good correlation with motion capture system (r = 0.637-0.979). The test-retest reliability of the Swaymeter showed moderate to good reliability for immediate test-retest (ICC = 0.51-0.87). However, inter-session reliability revealed moderate to good reliability except for the AP variable that showed low reliability. Good to excellent reliability was found in sway area variable (ICCs between 0.74 and 0.92) for all measurements.

Postural sway measure by Swaymeter was valid and reliable in typically developing children aged 7-12 years and suitable for applying to assess postural sway in typically developing children.