Purpose:
The study aimed to determine the within- and between-session reliabilities as well as the minimal detectable change (MDC) of generally used temporal, kinematic, and kinetic parameters during the sit-to-stand (STS) task in typical children.

Methods:
The study involved 10 typical children (9.8 ± 1.6 years old). Motion analysis and force plate systems were used to collect markers for 3-dimensional trajectories in space and measure the ground reaction force. The total of 29 reflective markers were placed on each participant’s body in accordance with the Helen Hays marker set model by 1 rater on 2 separate days within the span of 1 week. Each subject was asked to perform an STS task 3 times from a height-adjustable chair. Intraclass correlation coefficient (ICC), standard error of measurement (SEM), and MDC for temporal, kinematic, and kinetic parameters were calculated within and between sessions.

Results:
The results indicated that the temporal parameters achieved excellent (ICC > 0.75), the kinematic parameters presented poor to excellent (0.232 < ICC < 0.997), and the kinetic parameters showed fair to excellent (0.635 < ICC < 0.977) reliabilities in both within- and between-session analyses. The SEM of most kinematic parameters was less than 2° both within and between sessions. In addition, the MDC values for between sessions ranged 1.25–12.64°.

Conclusions:
The findings support the reliability of using 3-dimensional motion analysis and force plate systems for measuring temporal, kinematic, and kinetic parameters for STS tasks in typical children.