Validity of clinical outcome measures to evaluate ankle range of motion during the weight-bearing lunge test

Objectives: To determine the concurrent validity of standard clinical outcome measures compared to laboratory outcome measure while performing the weight-bearing lunge test (WBLT). Design: Cross-sectional study. Methods: Fifty participants performed the WBLT to determine dorsiflexion ROM using four different measurement techniques: dorsiflexion angle with digital inclinometer at 15 cm distal to the tibial tuberosity (degrees), dorsiflexion angle with inclinometer at tibial tuberosity (degrees), maximum lunge distance (cm), and dorsiflexion angle using a 2D motion capture system (degrees). Outcome measures were recorded concurrently during each trial. To establish concurrent validity, Pearson product-moment correlation coefficients (r) were conducted, comparing each dependent variable to the 2D motion capture analysis (identified as the reference standard). A higher correlation indicates strong concurrent validity. Results: There was a high correlation between each measurement technique and the reference standard. Specifically the correlation between the inclinometer placement at 15 cm below the tibial tuberosity (44.9 degrees +/- 5.5 degrees) and the motion capture angle (27.0 degrees +/- 6.0 degrees) was r = 0.76 (p = 0.001), between the inclinometer placement at the tibial tuberosity angle (39.0 degrees +/- 4.6 degrees) and the motion capture angle was r = 0.71 (p = 0.001), and between the distance from the wall clinical measure (10.3 +/- 3.0 cm) to the motion capture angle was r = 0.74 (p = 0.001). Conclusions: This study determined that the clinical measures used during the WBLT have a high correlation with the reference standard for assessing dorsiflexion range of motion. Therefore, obtaining maximum lunge distance and inclinometer angles are both valid assessments during the weight-bearing lunge test. (C) 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.