前交叉韧带重建术后六个月单腿垂直跳中离心期双下肢力学特征的选择性差异
简介
一项前瞻性研究纳入22例ACL重建术后6个月男性患者与22例匹配对照，通过力台分析单腿反向跳离心期力学指标。结果仅发现峰值离心力存在组别×肢体交互作用（校正后无统计学意义），离心冲量、位移及速度均无组间差异；主成分分析与聚类显示的多维模式在对照组同样存在。提示术后6个月跳跃离心力学改变具有选择性且缺乏特异性，解读时应谨慎，可作为康复评估的探索性参考。
英文摘要
OBJECTIVES: To investigate inter-limb eccentric mechanical characteristics during the single-leg countermovement jump (SLCMJ) six months after anterior cruciate ligament reconstruction (ACLR), and secondarily to explore multidimensional patterns across eccentric variables. DESIGN: Prospective observational study. SETTING: Laboratory-based biomechanical assessment using force platforms. PARTICIPANTS: Forty-four male participants (22 ACLR at 6 months after ACLR, 22 matched controls). MAIN OUTCOME MEASURES: Peak eccentric force, eccentric impulse, center of mass displacement, and eccentric velocity during the eccentric phase. Variables were standardised using control-referenced z-scores. Inter-limb differences were analysed using linear mixed-effects models. Principal component analysis (PCA) and exploratory k-means clustering examined multidimensional patterns, with k-selection and control-group sensitivity analyses. RESULTS: A group × limb interaction was found for peak eccentric force (β = 0.354, 95% CI 0.049 to 0.658; p = 0.023), although the Holm-adjusted sensitivity p value was 0.092; no interaction was observed for impulse (p = 0.858), displacement (p = 0.605), or velocity (p = 0.546). PCA identified two components explaining 87.2% of variance (PC1: 59.6%, PC2: 27.6%). The forced k = 2 ACLR partition comprised 11 and 11 participants (silhouette = 0.39), but the gap statistic favoured k = 1; comparable forced partitions were also observed in control limbs. CONCLUSIONS: Peak eccentric force showed a selective group × limb interaction, but this finding was sensitive to multiplicity and to the non-equivalent limb axes used across groups. Multidimensional patterns were also present in controls and should be considered exploratory rather than ACLR-specific.