Correlation Among Y-Balance Test-Lower Quarter Composite Scores, Hip Musculoskeletal Characteristics, and Pitching Kinematics in NCAA Division I Baseball Pitchers.

Context : Numerous studies have reported kinematic data on baseball pitchers using three-dimensional (3D) motion analysis, but no studies to date have correlated this data with clinical outcome measures. Objective : To examine the relationship among Y-Balance Test-Lower Quarter (YBT-LQ) composite scores, musculoskeletal characteristics of the hip, and pitching kinematics in National Collegiate Athletic Association (NCAA) Division I baseball pitchers. Design : Cross-sectional. Setting : 3D motion analysis laboratory. Participants : Nineteen healthy male college baseball pitchers. Main Outcome Measures : Internal and external hip passive range of motion, hip abduction strength, YBT-LQ composite scores, and kinematic variables of the pitching motion. Results : Stride length demonstrated a moderate positive correlation with dominant limb YBT-LQ composite score ( r  = .524, P  = .02) and nondominant limb YBT-LQ composite score ( r  = .550, P  = .01), and a weak positive correlation with normalized time to maximal humerus velocity ( r  = .458, P  = .04). Stride length had a moderate negative correlation with normalized time to maximal thorax velocity ( r  = -.522, P  = .02) and dominant hip total rotational motion (TRM; r  = -.660, P  = .002), and had a strong negative correlation with normalized time from stride foot contact to maximal knee flexion ( r  = -.722, P  < .001). Dominant limb YBT-LQ composite score had a weak negative correlation with hip abduction strength difference ( r  = -.459, P  = .04) and normalized time to maximal thorax velocity ( r  = -.468, P  = .04). Nondominant limb YBT-LQ composite score demonstrated a weak negative correlation with normalized time to maximal thorax velocity ( r  = -.450, P  = .05) and had a moderate negative correlation with dominant hip TRM ( r  = -.668, P  = .001). There were no other significant relationships between the remaining variables. Conclusions : YBT-LQ is a clinical measure that can be used to correlate with hip musculoskeletal characteristics and pitching kinematics in NCAA Division I pitchers.