Ankle dorsiflexion range of motion and hip abductor strength can predict Lower Quarter Y-Balance Test performance in healthy males

Objectives: The aim of the study was to assess whether strength and range of motion (ROM) of the hip and ankle are the factors determining performance in the Lower Quarter Y-Balance test (YBT-LQ). Design: Cross-sectional study. Participants: 66 healthy males (age: 25.2 +/- 6.8 years) participated in this study. Main outcome measures: Participants underwent assessments of ankle dorsiflexion (DF) ROM, hip internal rotation (IR) ROM, external rotation (ER) ROM and isometric strength of hip abductor (ABD), extensor (EXT) and external rotators (ERS) muscles together with YBT-LQ for both legs. A forward 2-steps multiple linear regression analysis was conducted to examine the relationship between the predictor variables and the criterion variable. Results: Ankle DF ROM predicted anterior (ANT) reach (R-2 = 0.49; R-2 = 0.33; p < 0.001). The model with hip ABD strength and ankle DF ROM explained posteromedial (PM) reach variance for stance leg (R-2 = 0.35; p < 0.001), while only hip ABD strength was included for kicking leg (R-2 = 0.19; p = 0.007). The model with ankle DF ROM and hip ABD strength explained posterolateral (PL) reach for stance leg (R-2 = 0.41; p < 0.001). Hip ABD was the only predictor for kicking leg PL reach (R-2 = 0.15; p < 0.001). YBT-LQ composite score was explained by ankle DF ROM and hip ABD strength for both legs (R-2 = 0.44; p < 0.001) and (R-2 = 0.25; p = 0.002). Conclusion: Hip ABD strength and ankle DF ROM can determine performance in the YBT-LQ. Strength of hip EXT, ERS as well as ROM of hip IR and ER did not predict YBT-LQ performance.