高强度耐力运动过程中肌腱结构及力学性质的变化

Alterations of the structure and biomechanics property of tendon during high intensity endurance exercise

目的:观察高强度耐力性训练对肌腱结构、力学性质的影响。方法:实验于2002-03/07在解放军第一五○医院全军军事医学研究所完成,健康10个月龄豚鼠70只,随机数字法分为实验组及对照组,对照组10只,实验组60只,实验组中再次随机数字法分为6组,分别于实验第1～6周投入运动训练,实验动物于特制跑台内进行运动训练,跑道速度25m/min,坡度为0,时间1h,共计跑步1500m,训练6d/周,训练结束所有动物一并取材,分别取双侧跟腱,左右分开,左侧跟腱行透射电镜观察超微结构,右侧跟腱在材料实验机上进行生物力学性质测试,根据肌腱的负荷-形变曲线测量屈服强度、应变、能量吸收指标。结果:实验豚鼠70只均进入结果分析。①超微结构观察,运动实验过程中肌腱中胶原纤维束直径逐渐减小,第6周实验组中肌腱中大量纤细胶原纤维束平行密集排布,且第4周时发现沿胶原纤维束走行出现微小空虚区,纤维束连续性中断,提示肌腱中微损伤出现。②生物力学性质检测运动过程中肌腱屈服强度和能量吸收训练1周组高于对照组,训练4周组低于对照组,能量吸收随屈服强度相应变化,应变在训练过程中无明显变化,提示肌腱在短时间高强度训练过程中出现强度下降现象[屈服强度:对照组(86.438±5.505)kN,训练1周组(92.731±4.511)kN,训练4周组(82.218±5.234)kN;能量吸收:对照组(0.207±0.027)kJ,训练1周组(0.254±0.030)kJ,训练4周组(0.192±0.035)kJ,P<0.05]。结论:肌腱对运动训练可发生适应性改建,在此过程中伴随着疲劳性损伤发生。

AIM： To study the effect of high intensity endurance exercise on the structure and biomechanics property of tendon. METHODS： The study was carded out in Military Training Medicine Institute, the 150 Hospital of Chinese PLA during March to July in 2002. Seventy healthy guinea pigs often months old ware assigned into two groups at random： the control group （n =10） and experimental group （n =60）, and the experimental group was divided into 6 sets based on training time, The experimental groups began training from the 1^st-6^th weeks, and all animals were forced to run in the self-made device at the speed of 25 m per minute, the gradient of 0 and the exercise time of 1 hour, the animals ware trained 6 days per week, totally 1 500 m, The right and left Achilles tendons were harvested and separated after 6-week training. The ulstrastructure of left Achilles tendon was observed through transmission electron microscope, and the biomechanics property, including yield stress, strain and energy absorption, was observed on material testing device according to load-deformation diagram of tendon. RESULTS： All the 70 guinea pigs were involved in the result analysis.①Ultrastructure observation： Diameter of collagen fibrils decreased during exercise, and there were a great deal of parallel and dense fascicules arranging in collagen fibrils on the 6^th week, and tiny vacuity appeared along with the fascicules that was interrupted continuously, suggesting tendon was slightly injured. ②Biomechanics property test of Achilles tendon： Yield stress and energy absorption were higher in the experimental group at week 1 than in the control group, but lower in the experimental group at week 4 than in the control group. Energy absorption changed consistently with yield stress, and the strain of tendons remained, which suggested that the tendon turned to decline during short term of high intensive endurance exercise [Control group： （66.438±5.505） kN, （0.207±0.027） k J; 1^st week： （92.731±4.511）kN, （0.254±0.030） k J; 4^th week： （82.216±5.234） kN, （0.192±0.035） k J, P〈 0.05]. CONCLUSION： Tendon can adapt to the exercise training, and there is fatigue damage in tendon during this adaptation process.