Single-Leg Squat Performance and Reported Pain within Youth Softball Players

The purpose of this study was to assess single-leg squat (SLS) performance on reported pain. Forty-two youth softball athletes (13.0 +/- 2.0 years; 162.19 +/- 9.75 cm; 60.80 +/- 14.28 kg) completed a bilateral SLS and a health history questionnaire in which they indicated if they were currently experiencing any pain/discomfort. Due to the clinical significance of the current study, p < 0.10 was classified as nearing significance. A point-biserial correlation was run between the groups (pain and no pain) and all kinematic variables (maximal knee flexion, knee valgus/varus, vertical sacrum displacement, anterior pelvic tilt, and pelvic lateral tilt) at each event (45 degrees descent, maximal knee flexion, and 45 degrees ascent), across each phase (descent, ascent), and between legs. Increased vertical sacrum displacement was correlated with pain at 45 degrees ascent and at maximal knee flexion in the right SLS. Knee valgus at maximal knee flexion, 45 degrees ascent, and in the decent phase of the left SLS was significant. Anterior pelvic tilt in the decent phase of the left SLS and knee valgus and pelvic lateral tilt in the decent phase of the right SLS were found to be significantly correlated with pain. Poor SLS performance was correlated with reported pain.