Association of Ankle Kinematics and Performance on the Y-Balance Test With Inclinometer Measurements on the Weight-Bearing-Lunge Test

Context: Ankle-dorsiflexion range of motion has often been measured in the weight-bearing condition in the clinical setting; however, little is known about the relationship between the weight-bearing-lunge test (WBLT) and both ankle kinematics and performance on dynamic postural-control tests. Objective: To examine whether ankle kinematics and performance on the Lower Quarter Y-Balance Test (YBT-LQ) are correlated with results of the WBLT using an inclinometer and tape measure. Design: Cross-sectional. Setting: University motionanalysis laboratory. Participants: 30 physically active participants. Interventions: None. Main Outcome Measures: The WBLT was evaluated using an inclinometer and a tape measure. The reach distances in the anterior, posteromedial, and posterolateral directions on the YBT-LQ were normalized by limb length. Ankle dorsiflexion during the YBT-LQ was recorded using a 3-dimensional motion-analysis system. Simple linear regression was used to examine the relationship between the WBLT results and both ankle dorsiflexion and the normalized reach distance in each direction on the YBT-LQ. Results: The WBLT results were significantly correlated with ankle dorsiflexion in all directions on the YBT-LQ ( P < .05). A strong correlation was found between the inclinometer measurement of the WBLT and ankle dorsiflexion ( r = .74, r 2 = .55), whereas the tape-measure results on the WBLT were moderately correlated with ankle dorsiflexion ( r = .64, r 2 = .40) during the anterior reach on the YBT-LQ. Only the normalized anterior reach distance was significantly correlated with the results for the inclinometer ( r = .68, r 2 = .46) and the tape measure ( r = .64, r 2 = .41) on the WBLT. Conclusions: Inclinometer measurements on the WBLT can be an appropriate tool for predicting the amount of ankle dorsiflexion during the YBT-LQ. Furthermore, WBLT should be measured in those who demonstrate poor dynamic balance.