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

Abstract 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 (°), dorsiflexion angle with inclinometer at tibial tuberosity (°), maximum lunge distance (cm), and dorsiflexion angle using a 2D motion capture system (°). 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° ± 5.5°) and the motion capture angle (27.0° ± 6.0°) was r = 0.76 (p = 0.001), between the inclinometer placement at the tibial tuberosity angle (39.0° ± 4.6°) 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.