title: Relationships between lower-extremity flexibility, asymmetries, and the Y balance test.
abstract: Joint flexibility, bilateral asymmetries in flexibility, and bilateral asymmetries in performance of the Y Balance Test have been associated with injuries. However, relationships among these attributes are unclear. The goal of this investigation was to examine how flexibility and flexibility asymmetries relate to the Y Balance Test. Twenty healthy active young adults (9 men and 11 women; mean ± SD: age = 21.9 ± 2.6 years; height = 171 ± 8.8 cm; mass = 67.2 ± 1.9 kg) performed 9 different lower extremity active range of motion (AROM) tests and the Y Balance Test in a single visit. Significant correlations (p ≤ 0.05) existed between bilateral average AROM measures and bilateral average Y Balance Test scores at the ankle and hip. Specifically, ankle dorsiflexion AROM at 0° knee flexion significantly correlated with Anterior, Posterolateral, and Composite directional scores of the Y Balance Test (r = 0.497-0.736). Significant correlations in ankle dorsiflexion AROM at 90° knee flexion also existed with Anterior, Posterolateral, Posteromedial, and Composite directional scores (r = 0.472-0.795). Hip flexion AROM was significantly correlated with Posterolateral, Posteromedial, and Composite directional scores (r = 0.457-0.583). Significant correlations between asymmetries in AROM and asymmetries in the Y Balance Test existed only in ankle plantarflexion with Anterior, Posterolateral, and Composite directional scores of the Y Balance Test (r = 0.520-0.636). Results suggest that when used with recreationally active healthy adults, the Y Balance Test may help identify lower-extremity flexibility deficits and flexibility asymmetries in the ankle and hip regions but may need to be used in conjunction with additional tests to understand a broader picture of functional movement and injury risk.
authors.affiliation: 1Clinical Biomechanics Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, Colorado; and 2School of Biomedical Engineering, Colorado State University, Fort Collins, Colorado.
authors.forename: Grant V
authors.initials: GV
authors.lastname: Overmoyer
authors.forename: Raoul F
authors.initials: RF
authors.lastname: Reiser
mesh_terms: D000843:Ankle Joint / Q000502:physiology; D005260:Female; D006621:Hip Joint / Q000502:physiology; D006801:Humans; D007719:Knee Joint / Q000502:physiology; D035002:Lower Extremity; D008297:Male; D009068:Movement / Q000502:physiology*; D009141:Musculoskeletal System / Q000293:injuries; D004856:Postural Balance / Q000502:physiology*; D016059:Range of Motion, Articular / Q000502:physiology*; D018570:Risk Assessment; D055815:Young Adult