Differences in lower-extremity strength and power between elite hockey players with and without patellar asymptomatic tendon thickening; unilateral and bilateral comparative analysis

Introduction Existing research shows that while patellar tendinopathy in ice hockey players is linked to cumulative mechanical overload, structural tendon changes such as thickening or degeneration do not reliably correspond to pain or performance deficits, leaving the functional impact of asymptomatic tendon pathology unclear. Thus, the aim of this study was to identify differences in lower-extremity strength and power between elite ice hockey players with and without patellar asymptomatic tendon thickening using unilateral and bilateral comparisons. Methods This cross-sectional study combined clinical screening, performance testing, and ultrasound imaging to characterize patellar tendon structure and lower-extremity function. Players were objectively classified into healthy ( n = 8), unilateral (n = 8), or bilateral patellar asymptomatic tendon thickening ( n = 12) groups based on patellar tendon thickness and width. Strength and power outcomes were assessed under controlled conditions and normalized to body mass to allow fair between-group comparisons. Isokinetic concentric strength was evaluated during a split squat performed on a robotic resistance device, while peak power output was measured using a six-second all-out cycling test on a calibrated ergometer. Results Relative power output was significantly higher in the healthy group (20.3 ± 1.7 W·kg⁻¹) compared with the bilateral patellar asymptomatic tendon thickening group (18.6 ± 1.1 W·kg⁻¹; p = 0.047), whereas no between-group differences were observed for relative peak force or absolute power (all p 0.45). No significant left-right differences in peak force were detected within any group (all p ≥ 0.12). Discussion Asymptomatic bilateral patellar tendon thickening was associated with a modest but significant reduction in relative power output in elite hockey players, whereas unilateral tendon changes did not impair performance. These findings suggest that bilateral structural tendon alterations may negatively influence power-generating capacity even in the absence of clinical symptoms. Clinical Trial Registration: https://clinicaltrials.gov/study/NCT07356596 , PROSPERO NCT073566.