Faculty of Sport Sciences, Waseda University, Saitama, Japan.
J Magn Reson Imaging. 2011 Oct;34(4):887-94. doi: 10.1002/jmri.22668. Epub 2011 Jul 18.
To assess the effects of strenuous exercise on magnetic resonance diffusion parameters and muscle-tendon complex function in skeletal muscle.
Six men performed ankle plantar flexion exercises with eccentric contraction. The fractional anisotropy (FA), λ(1) , λ(2) , λ(3) , mean diffusivity (MD), and T(2) values in the triceps surae muscles were measured by magnetic resonance diffusion tensor and spin-echo imaging. Passive torque of plantar flexors, maximal voluntary isometric plantar flexion torques (MVIP), and Achilles tendon stiffness during MVIP were measured by combined ultrasonography and dynamometry. Plasma creatine kinase and muscle soreness were also assessed. These parameters were measured before and 1-8 days postexercise.
The medial gastrocnemius exhibited significantly decreased FA 2-5 days after, increased λ(2) 3 days after, and increased λ(3) 2 and 3 days after exercise. This muscle also showed significantly increased MD and T(2) values 3 days postexercise. MVIP significantly decreased 2 and 3 days postexercise, while passive torque significantly increased 2 days postexercise. Creatine kinase and muscle soreness increased 3-5 days and 1-5 days postexercise, respectively.
Exercise-induced muscle damage manifested as significant changes in muscle diffusion parameters with muscle-tendon complex dysfunction and delayed-onset muscle soreness.
评估剧烈运动对骨骼肌磁共振扩散参数和肌肉-肌腱复合体功能的影响。
6 名男性进行了带有离心收缩的踝关节跖屈运动。使用磁共振扩散张量和自旋回波成像测量比目鱼肌的各向异性分数（FA）、λ(1)、λ(2)、λ(3)、平均扩散系数（MD）和 T(2)值。通过超声和测力仪测量跖屈肌的被动扭矩、最大自主等长跖屈扭矩（MVIP）和 MVIP 期间的跟腱刚度。还评估了血浆肌酸激酶和肌肉酸痛。这些参数在运动前和运动后 1-8 天进行测量。
内侧腓肠肌在运动后 2-5 天出现明显的 FA 降低，在运动后 3 天出现 λ(2)增加，在运动后 2 和 3 天出现 λ(3)增加。该肌肉还在运动后 3 天出现明显的 MD 和 T(2)值增加。MVIP 在运动后 2 和 3 天显著下降，而被动扭矩在运动后 2 天显著增加。肌酸激酶和肌肉酸痛分别在运动后 3-5 天和 1-5 天增加。
运动引起的肌肉损伤表现为肌肉扩散参数的显著变化，同时伴有肌肉-肌腱复合体功能障碍和迟发性肌肉酸痛。
