A Kinematic Comparison Between Sit-to-Stand Movements and Individual Cycles of the 5-Cycle Sit-to-Stand Test

Objective The 5-cycle sit-to-stand (5XSTS) test is frequently used to test physical function for different clinical populations, with time to complete as the measured outcome. This study evaluated the similarity of kinematics between a single cycle of the STS movement and individual cycles of the 5XSTS test. Methods Lower extremity, pelvis, and thorax kinematic data were monitored as 20 participants (aged 18-40) completed 5 trials of the STS movement and 1 trial of the 5XSTS test. Correlations and root mean squared differences assessed the temporal and spatial similarities in kinematic patterns of sagittal plane joint angles at the ankles, knees, hips, and spine between single cycles of the STS movement and individual cycles of the 5XSTS test. Peak joint angles were obtained along with discrete angles at the start, seat off, and end of the movement. Results Temporal and spatial similarity of kinematics for the ankles and hips were reduced over cycles 2 to 5 of the 5XSTS. Increased hip flexion was observed at the start of cycles 2 to 5 of the 5XSTS test. Increased knee and hip flexion were observed at the end of cycles 1 to 4 of the 5XSTS test. Conclusions Temporal patterns of sagittal plane joint angles captured in the first cycle of the 5XSTS represented those adopted for an isolated STS movement. Different initial conditions for cycles 2 to 5 of the 5XSTS 58 may have reduced temporal and spatial similarity of sagittal plane joint angles of the ankles and hips.