Muscle architecture change due to exercise and its effect on muscle circulation

本研究的目的是确定运动过程中肌肉结构变化对肌肉循环的影响。分别采用b超法、近红外光谱法和多普勒超声法测量静屈足底运动时肌束长度、肌肉氧合和股动脉血流量。与90度踝关节角相比，运动时110度踝关节角的股动脉血流量更高，而运动后立即的血流量在110度踝关节角时更低。与90度踝关节角相比，110度踝关节角时股束长度缩短得更多。在90度和110度踝关节角时肌肉产生的估计张力没有显著差异。尽管踝关节处的最大扭矩在90度时明显更高。因此，110度时更高的血流量可归因于较短的肌纤维长度。然而，运动时肌肉氧合在两个踝关节位置之间没有差异。在15/min频率的动态足底屈曲运动中，小腿肌肉的肌肉氧作用和股动脉血流在每个工作循环中随肌肉收缩和舒张而波动。这些变化主要取决于肌肉张力的改变，而不是由于肌肉结构的改变。

The purpose of this study was to determine the effect of muscle architecture changes on muscle circulation during exercise. Fascicle length, muscle oxygenation, and femoral arterial blood flow were measured during static plantar flexion exercise using B-mode ultrasound method, near-infrared spect-roscopy, and Doppler ultrasound method, respectively. Femoral arterial blood flow was higher during exercise at 110 deg of ankle joint angle compared to that at 90 deg, whereas immediate post-exercise blood flow was lower at 110 deg. Fascicle length was more shortened at 110 deg compared to 90 deg. The estimated tension developed in the muscle at 90 deg and 110 deg were not significantly different, though the maximal torque at the ankle joint was significantly higher at 90 deg. Consequently higher blood flow at 110 deg will be attributable to shorter muscle fiber length. However, muscle oxygenation during exercise did not differ between 2 ankle joint positions. During dynamic plantar flexion exercise at the frequency of 15/min, the muscle oxygen action of calf muscle and femoral arterial blood flow fluctuated during each duty cycle depending on the muscle contraction and relaxation. These changes predominatly depend on the alteration of the muscle tension rather than due to changes in the muscle architecture.