Nordez A, McNair P, Casari P, Cornu C
Université de Nantes, Nantes Atlantique Universités, Laboratoire Motricité, Interactions, Performance, JE 2438, UFR STAPS, Nantes, France.
Int J Sports Med. 2008 May;29(5):414-8. doi: 10.1055/s-2007-964980. Epub 2007 Sep 13.
This study was designed to measure changes in musculo-articular dissipative properties related to viscosity that were induced by passive cyclic and static stretching. Musculo-articular dissipative properties were assessed by calculating a dissipation coefficient using potential elastic energies stored and restituted during cyclic stretching. Eight subjects performed five passive knee extensions/flexions cycles on a Biodex dynamometer at 5 degrees . s (-1) to 80 % of their maximal range of motion before and after a static stretching protocol. Electromyographic activity from the hamstring muscles was monitored and remained constant during cyclic stretching and after static stretching (p > 0.05). The dissipation coefficient decreased during cyclic stretching (- 28.8 +/- 6.0 %, p < 0.001), while it was slightly increased after static stretching (+ 3.8 +/- 5.0 %, p = 0.037). The findings showed that energy stored and energy restituted decreased during cyclic stretching and after static stretching (p < 0.05). During unloading, passive torque remained constant during cyclic stretching, but was decreased after static stretching. The findings indicate that musculo-articular dissipative properties were primarily affected by a single cycle of motion, and were not influenced by static stretching procedures. The decrease in dissipation coefficient following cyclic motion indicates that the musculo-articular system displays thixotropic behavior.
本研究旨在测量被动循环拉伸和静态拉伸所引起的与粘性相关的肌肉关节耗散特性的变化。通过使用循环拉伸过程中储存和恢复的潜在弹性能量来计算耗散系数，从而评估肌肉关节耗散特性。八名受试者在静态拉伸方案前后，以5度·秒（-1）至其最大运动范围的80%在Biodex测力计上进行五次被动膝关节屈伸循环。监测了绳肌的肌电图活动，其在循环拉伸期间和静态拉伸后保持恒定（p>0.05）。循环拉伸期间耗散系数降低（-28.8±6.0%，p<0.001），而静态拉伸后略有增加（+3.8±5.0%，p = 0.037）。研究结果表明，循环拉伸期间和静态拉伸后储存的能量和恢复的能量均降低（p<0.05）。在卸载过程中，循环拉伸期间被动扭矩保持恒定，但静态拉伸后被动扭矩降低。研究结果表明，肌肉关节耗散特性主要受单个运动周期的影响，不受静态拉伸程序的影响。循环运动后耗散系数的降低表明肌肉关节系统表现出触变性行为。
