PURPOSE Sprinting often provokes hip pain in individuals with femoroacetabular impingement syndrome (FAIS). Asphericity of the femoral head-neck junction (cam morphology) characteristic of FAIS can increase risk of anterior-superior acetabular cartilage damage. This study aimed to: 1) compare hip contact forces (magnitude and direction) during sprinting between individuals with FAIS, asymptomatic cam morphology (CAM), and controls without cam morphology, and 2) identify the phases of sprinting with high levels of anteriorly directed hip contact forces. METHODS Forty-six recreationally active individuals with comparable levels of physical activity were divided into three groups (FAIS = 14; CAM = 15; control = 17) based on their history of hip/groin pain, results of a clinical impingement test, and presence of cam morphology (alpha angle>55°). Three-dimensional marker trajectories, ground reaction forces, and electromyograms (EMG) from 12 lower-limb muscles were recorded during 10 m overground sprinting trials. A linearly scaled EMG-informed neuromusculoskeletal model was used to calculate hip contact force magnitude (resultant, anterior-posterior, inferior-superior, medio-lateral) and angle (sagittal and frontal planes). Between-group comparisons were made using 2-sample t-tests via statistical parametric mapping (P < 0.05). RESULTS No significant differences in magnitude or direction of hip contact forces were observed between FAIS and CAM or between FAIS and control groups during any phase of the sprint cycle. The highest anteriorly directed hip contact forces were observed during the initial swing phase of the sprint cycle. CONCLUSIONS Hip contact forces during sprinting do not differentiate recreationally active individuals with FAIS from asymptomatic individuals with and without cam morphology. Hip loading during early swing, where peak anterior loading occurs, may be a potential mechanism for cartilage damage during sprinting related sports in individuals with FAIS and/or asymptomatic cam morphology.

中文翻译：

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股髋臼撞击综合征冲刺期间的髋部接触力。

目的 短跑经常会引起股骨髋臼撞击综合征 (FAIS) 患者的髋部疼痛。FAIS 股骨头颈连接处（凸轮形态）特征的非球面性会增加髋臼前上软骨损伤的风险。本研究旨在：1) 比较具有 FAIS、无症状凸轮形态 (CAM) 和无凸轮形态的对照个体在冲刺期间的髋部接触力（大小和方向），以及 2) 确定具有高水平前向定向的冲刺阶段髋部接触力。方法 根据髋部/腹股沟疼痛史、临床撞击测试结果和存在情况，将 46 名具有可比体力活动水平的休闲活跃个体分为三组（FAIS = 14；CAM = 15；对照 = 17）凸轮形态（α角> 55°）。在 10 m 地上冲刺试验中记录了 3 维标记轨迹、地面反作用力和 12 块下肢肌肉的肌电图 (EMG)。使用线性缩放的肌电图信息神经肌肉骨骼模型来计算髋部接触力大小（合成力、前后力、下上力、中外侧力）和角度（矢状面和额状面）。通过统计参数映射使用 2 样本 t 检验进行组间比较（P < 0.05）。结果 在冲刺周期的任何阶段，FAIS 和 CAM 之间或 FAIS 和对照组之间髋部接触力的大小或方向均未观察到显着差异。在冲刺周期的初始摆动阶段观察到最高的向前指向的髋部接触力。结论 短跑期间髋部接触力并不能区分患有 FAIS 的休闲活跃个体与具有或不具有凸轮形态的无症状个体。早期摆动期间的髋部负荷（前负荷峰值发生）可能是具有 FAIS 和/或无症状凸轮形态的个体在短跑相关运动期间软骨损伤的潜在机制。