Gillis C, Sharkey N, Stover S M, Pool R R, Meagher D M, Willits N
Veterinary Medical Teaching Hospital, University of California, Davis 95616, USA.
Am J Vet Res. 1995 Oct;56(10):1345-50.
Results of studies in human beings and other species have indicated that aging significantly influences the strength, modulus of elasticity, and energy storage ability of tendon. We wanted to determine the effects of aging on the material and ultrasonographic properties of equine superficial digital flexor (SDF) tendon. Ultrasonographic measurements of left forelimb SDF tendon cross-sectional area and mean echogenicity were made in 23 standing horses ranging in age from 2 to 23 years. All horses had not been in work for a minimum of 6 months prior to the study. After euthanasia, left forelimb bone-muscle-tendon-bone specimens were mounted in a materials testing system. The SDF tendon was cyclically loaded sinusoidally 100 times at 0.5 Hz from 1.5 to 5.0% strain, then was submitted to 10-minute creep-and-stress relaxation tests. Modulus of elasticity, load at 3% strain, and creep-and-stress relaxation were determined for each specimen. A significant positive correlation was found between elastic modulus and age. Correlation was not found between age and SDF tendon cross-sectional area or mean echogenicity. When 2-year-old horses were compared with older horses, the latter had tendons with a significantly (P = 0.007) greater modulus of elasticity. The authors conclude that increasing age through maturity is associated with a corresponding increase in equine SDF tendon elastic modulus.
对人类和其他物种的研究结果表明，衰老会显著影响肌腱的强度、弹性模量和能量储存能力。我们想要确定衰老对马的浅屈指肌腱（SDF）的材料和超声特性的影响。对23匹年龄在2至23岁之间的站立马匹的左前肢SDF肌腱的横截面积和平均回声性进行了超声测量。在研究前，所有马匹至少6个月未工作。安乐死后，将左前肢骨-肌肉-肌腱-骨标本安装在材料测试系统中。SDF肌腱在0.5Hz频率下以1.5%至5.0%的应变进行100次正弦循环加载，然后进行10分钟的蠕变和应力松弛测试。测定每个标本的弹性模量、3%应变时的负荷以及蠕变和应力松弛。发现弹性模量与年龄之间存在显著正相关。未发现年龄与SDF肌腱横截面积或平均回声性之间存在相关性。将2岁的马与年龄较大的马进行比较时，后者的肌腱弹性模量显著更高（P = 0.007）。作者得出结论，随着年龄增长至成熟，马的SDF肌腱弹性模量相应增加。
