Consistency of Sit-to-walk Movement in Children with Typical Development Based on the New Non-Overlapping Phases

Objective: This study aimed to define sit-to-walk (STW) movement without phase overlap. In addition, the intrasubject and test-retest repeatability of movement events were measured. Material and Methods: Fifteen healthy children aged between 7 and 12 years old participated in the study. A threedimensional motion analysis system was used to gather and process the kinematic and kinetic data. Two sessions of STW movement were performed with a one-week interval. The intraclass correlation coefficient (ICC) with 95.0% confidence interval (CI) was calculated to determine the repeatability of the new proposed phases at each point of a movement event. The adjusted coefficient of multiple correlation (CMC) was used to evaluate the similarities of the entire STW waveforms. Results: Nine phases of STW were identified by the demands of movement performance. The ICC values indicated poor to excellent intrasubject (0.36-0.97) and test-retest repeatability (0.30-0.96). Poor repeatability was observed at the hip (0.30-0.44), knee (0.36), and ankle (0.47 and 0.49) joints only during the gait cycle. The CMC values demonstrated high to excellent (>0.75) intrasubject and test-retest repeatability, indicating the similarities of STW waveforms. Conclusion: Additional phase definitions of STW demonstrated an acceptable level of repeatability in the childhood population. Variations in the lower extremities could be related to the fluidity with which these children performed at the point of gait initiation. Thus, variability in joint angles could be produced by the different fluidities of initial walking.