Reliability and comparison of trunk and pelvis angles, arm distance and center of pressure in the seated functional reach test with and without foot support in children.

This study determined test-retest reliability of trunk and pelvis joint angles, arm distance and center of pressure (COP) excursion for the seated functional reach test (FRT) and compared these variables during the seated FRT with and without foot support. Fifteen typically developing children (age 9.3±4.1years) participated. Trunk and pelvis joint angles, arm distance, and COP excursion were collected on two days using three-dimensional motion analysis and a force plate while subjects reached maximally with and without foot support in the anterior, anterior/lateral, lateral, posterior/lateral directions. Age, weight, height, trunk and arm lengths were correlated (p<0.01) with maximum arm distance reached. Maximum arm distance, trunk and pelvis joint angles, and COP with and without foot support were not significant (p<0.05) for the two test periods. Excellent reliability (ICCs>0.75) was found for maximum arm distance reached in all four directions in the seated FRT with and without foot support. Most trunk and pelvis joint angles and COP excursions during maximum reach in all four directions showed excellent to fair reliability (ICCs>0.40-0.75). Reaching with foot support in all directions was significantly greater (p<0.05) than without foot support; however, most COP excursions and trunk and pelvic angles were not significantly different. Findings support the addition of anterior/lateral and posterior/lateral reaching directions in the seated FRT. Trunk and pelvis movement analysis is important to examine in the seated FRT to determine the specific movement strategies needed for maximum reaching without loss of balance.