即刻改变触地方式对着鞋跑时内侧纵弓在体运动学的影响

目的 探究即刻转换触地方式对着鞋跑步时内侧纵弓在体运动学的影响。 方法 采用高速双平面荧光透视成像系统采集 15 名健康男性跑者即刻改变触地方式前后右足在跑步支撑阶段跑速:(3±0. 15) m/ s]的荧光图像。根据 CT 图像重建第 1 跖骨和跟骨三维骨骼模型及其局部坐标系,并通过 3D-2D 配准获取内侧纵弓在跑步支撑期的 6 自由度(six degree of freedom,6 DOF) 数据(简化为第 1 跖骨相对跟骨的运动)。 采用一维统计参数映射(statistical parametric mapping,SPM)比较即刻改变触地方式前后内侧纵弓的 6 DOF 运动趋势,并对其特征值进行配对样本 t 检验。 结果 相比后跟跑,即刻前掌跑时,在支撑期的 15% ~ 21% 第 1 跖骨相对跟骨的外移、支撑期 17% ~45% 第 1 跖骨的前移和支撑期的 18% ~ 39% 第 1 跖骨的背屈均显著增加(P<0. 05)。 即刻前掌跑时,第 1 跖骨相对跟骨的前移最大值、背屈最大值、前后平移活动范围及内侧纵弓压缩变化量均显著增加(P<0. 05)。 结论 由习惯后跟跑即刻转换为前掌跑后,内侧纵弓矢状面的形变显著增加,尤其是内侧纵弓的压缩变化量增加约 10% ,可能有助于其弹性能量的储存与释放。

Acute Effects of Changing Foot Strike Patterns on in vivo Kinematics of Medial Longitudinal Arch During Shod Running

Objective To investigate the acute effect of changing foot strike patterns on in vivo kinematics of the medial longitudinal arch during shod running. Methods The high-speed dual fluoroscopic imaging system(DFIS) was used to acquire fluoroscopic images of the right foot during stance phase before and after changing foot strike patterns running speed: (3±0. 15) m / s] in 15 healthy male runners. The three-dimensional (3D) model of the first metatarsal bone and calcaneus and the local coordinate system were reconstructed from CT images, and the six degrees of freedom (6 DOF) data of the medial longitudinal arch (simplified as motion of the first metatarsal bone relative to the calcaneus) during stance phase were obtained by 3D-2D registration. Statistical parametric mapping (SPM) was used to compare the 6 DOF data of the medial longitudinal arch before and after changing foot strike patterns, and paired sample t-tests were used to compare the specific values. Results Compared with rearfoot strike, the lateral translation during 15% -21% of stance phase, anterior translation during 17% -45% of stance phase and dorsiflexion during 18% -39% of stance phase for motion of the first metatarsal bone relative to the calcaneus were significantly increased during forefoot strike running ( P < 0. 05). The maximum anterior translation, the maximum dorsiflexion, the anterior-posterior translation, and the compression of the medial longitudinal arch for motion of the first metatarsal bone relative to the calcaneus were significantly increased during forefoot strike running (P<0. 05). Conclusions Transitioning from habitual rearfoot strike to immediate forefoot strike resulted in greater deformation of the medial longitudinal arch in sagittal plane, especially the variation of arch compression increased by approximately 10% , which might contribute to the storage and release of elastic energy in the medial longitudinal arch.