Examining the Joint Coordination during Dynamic Balance Learning using Vector Coding and Statistical Parametric Mapping Analyses

Abstract

Abstract The objective of this study was to examine the changes in balance performance, kinematic variables, and joint coordination of lower extremities during the entire Y-balance task learning. Twenty female university students completed five consecutive blocks of Y-balance learning from Days 3 to 7 (135 trials), a pre-test and test day were performed on Day 1 and Day 9. Maximum reach distance, peak joint angle, and joint coordination in anterior (AL), posterolateral (PL), and posteromedial (PM) directions were measured to indicate the efficacy of Y-balance performance. An ANOVA with repeated measures was performed for the maximum reach distance across learning blocks to confirm the learning occurred. Paired t-tests were used to compare maximum reach distance and joint angle variables between pre-test and test block to evaluate the differences in lower limb biomechanics. Alpha was set at 0.05. The results indicated that the maximum reach distance on Day 5 was longer than on other Days (p < .05). As for both PL and PM directions, the maximum reach distance was significantly increased after learning (p < .05). Hip flexion (PL/PM), abduction (PM), internal rotation (PM), external rotation (PL) angles were increased after learning. The knee joint flexion angle was increased in AL and PL directions. Only the ankle dorsiflexion angle was increased in the AL direction (p < .05). The joint coordination appeared that the knee and hip joints were performed in internal rotation simultaneously. Ankle and knee joint coordination was performed through dorsiflexion and flexion strategy (p < .05). The SPM analysis indicated, significant differences for ankle sagittal plane of AL direction, hip horizontal, hip/knee sagittal and hip/knee sagittal plane of PL direction, and hip/knee sagittal and hip frontal/horizontal plane of PM direction (p < .05). These data suggest that dynamic balance ability of novice participants can be improved which is related to the coordination pattern changes after learning. The results from this study can apply to other populations to improve dynamic balance for preventing fall injuries.