Abstract
Abstract
Background
The lower quarter Y‐balance test (YBT‐LQ) has been recommended as a measure of dynamic postural control in the clinical setting; however, information about the relationship between performance on the YBT‐LQ and joint kinematics is limited. Thus, the kinematic predictors responsible for performance on the YBT‐LQ need to be identified for accurate evaluation of dynamic postural control.
Objectives
To identify the kinematic predictors that best explain variance in performance on the YBT‐LQ.
Design
Cross‐sectional design.
Setting
University motion analysis laboratory.
Participants
Thirty physically active participants.
Methods
All participants performed the YBT‐LQ. The kinematics of the trunk and lower extremity at maximal reach in each direction of the YBT‐LQ were monitored using a 3‐dimensional motion analysis system.
Main Outcome Measurements
The correlations between reach distance and joint kinematics were assessed using Pearson's correlation coefficient, and the best predictors of performance on the YBT‐LQ were determined using a stepwise multiple regression analysis.
Results
Ankle dorsiflexion was the best single predictor of normalized reach in the anterior direction of the YBT‐LQ (r2 = 0.50), and the combination of ankle dorsiflexion and trunk extension explained 65% of the variance in the anterior normalized reach. Hip flexion was the best single predictor of posteromedial (r2 = 0.60) and posterolateral (r2 = 0.71) normalized reaches of the YBT‐LQ. The combination of hip flexion and ipsilateral trunk bending and the combination of hip flexion and contralateral trunk bending accounted for 69% and 80% of the variance in the posteromedial and posterolateral normalized reaches of the YBT‐LQ, respectively.
Conclusions
These findings provide useful information on the relative contribution of joint kinematics to performance on the YBT‐LQ when evaluating dynamic postural control.