Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand.
Department of Engineering Science, Faculty of Engineering, University of Auckland, Auckland, New Zealand; Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand.
J Biomech. 2019 Jun 11;90:103-112. doi: 10.1016/j.jbiomech.2019.04.046. Epub 2019 May 9.
The influence of ankle kinematics and plantar pressure from mid-range barefoot running on T2 relaxation times of tibiotalar cartilage is unknown. This study aimed to quantitatively evaluate the T2 relaxation time of tibiotalar cartilage and ankle biomechanics following 5 km barefoot running. Twenty healthy runners (who had no 5 km barefoot running experience) underwent 3.0-Tesla magnetic resonance (MR) scans and assessment of running gait before and after 5 km barefoot running. Participants were divided into two groups consisting of marathon-experienced (n = 10) and novice (n = 10) with equal number of males and females in each group. Three musculoskeletal radiologists measured T2 relaxation times in 18 regions of the ankle cartilage: anterior zone, central zone, and posterior zone, or lateral, middle, and medial sections in the sagittal plane. Three-dimensional ankle kinetics, kinematics, and plantar pressure were all also assessed during barefoot running. In the novice group, the T2 relaxation time in the posterior zone of tibial cartilage (p = 0.001) and lateral section in both tibial (p = 0.02) and talar (p = 0.02) cartilage were significantly increased after barefoot running. Ankle kinematics exhibited significant changes in females. Plantar loading was shifted from the medial to lateral aspect after running. This included a significant reduction in the loading under the toes and the 1st, 2nd and 3rd metatarsals, with a significant increase under the 4th and 5th metatarsals and lateral midfoot. The results suggest that plantar pressure may directly lead to local increases in cartilage T2 signal, which was not associated with changes in ankle kinematics.
中程赤脚跑步对距骨-跟骨软骨 T2 弛豫时间的影响尚不清楚。本研究旨在定量评估 5 公里赤脚跑后距骨-跟骨软骨的 T2 弛豫时间和踝关节生物力学。20 名健康跑步者（无 5 公里赤脚跑步经验）在 5 公里赤脚跑步前后接受了 3.0T 磁共振（MR）扫描和跑步步态评估。参与者分为两组，每组包括 10 名马拉松经验丰富的（n=10）和新手（n=10）跑步者，每组男女比例相等。3 名肌肉骨骼放射科医生测量了踝关节软骨 18 个区域的 T2 弛豫时间：前区、中区和后区，或矢状面中的外侧、中间和内侧部分。在赤脚跑步过程中，还评估了三维踝关节动力学、运动学和足底压力。在新手组中，胫骨软骨后区（p=0.001）和胫骨（p=0.02）和距骨（p=0.02）软骨外侧节段的 T2 弛豫时间在赤脚跑步后显著增加。女性的踝关节运动学发生了显著变化。跑步后，足底负荷从内侧转移到外侧。这包括脚趾和第 1、2 和 3 跖骨下的负荷显著减少，而第 4 和 5 跖骨和外侧中足下的负荷显著增加。结果表明，足底压力可能直接导致软骨 T2 信号的局部增加，而这与踝关节运动学的变化无关。
