Dynamic Postural Control Is Influenced by Single-Leg Squat Speed and Depth Under Single-Task and Dual-Task Paradigms.

Single-leg squats are a common dynamic balance clinical assessment. However, little is known about the relationship between parameters that influence squat movement and postural control performance. The objective of this study was to determine the relationships between squat parameters (speed and depth) and postural control under single-task and dual-task. Thirty healthy college students performed single-leg squats under single-task and dual-task with Stroop. Random intercepts general linear mixed models determined the effect of squat parameters on center of pressure parameters. For each 1 cm·s-1 increase in squat speed, sway range (medio-lateral: Beta = -0.03; antero-posterior: Beta = -0.05) and area (Beta = -0.25) decreased while sway speed (medio-lateral: Beta = 0.05; antero-posterior: Beta = 0.29; total: Beta = 0.29) increased. For each 1 cm increase in squat depth, sway range (medio-lateral: Beta = 0.05; antero-posterior: Beta = 0.20) and area (Beta = 0.72) increased while sway speed (antero-posterior: Beta = -0.14; total: Beta = -0.14) decreased. Compared to single-task, the association between total and antero-posterior sway speed and squat speed was stronger under dual-task. Clinicians and researchers should consider monitoring squat speed and depth when assessing dynamic balance during single-leg squats as these parameters influence postural control, especially under dual-task.