Epro Gaspar, Mierau Andreas, Doerner Jonas, Luetkens Julian A, Scheef Lukas, Kukuk Guido M, Boecker Henning, Maganaris Constantinos N, Brüggemann Gert-Peter, Karamanidis Kiros
Institute of Movement and Sport Gerontology, German Sport University Cologne, 50933 Cologne, Germany
Institute of Biomechanics and Orthopaedics, German Sport University Cologne, 50933 Cologne, Germany.
J Exp Biol. 2017 Mar 15;220(Pt 6):1008-1018. doi: 10.1242/jeb.146407.
The aging musculoskeletal system experiences a general decline in structure and function, characterized by a reduced adaptability to environmental stress. We investigated whether the older human Achilles tendon (AT) demonstrates mechanosensitivity (via biomechanical and morphological adaptations) in response to long-term mechanical loading. Thirty-four female adults (60-75 years) were allocated to either a medium-term (14 weeks; =21) high AT strain cyclic loading exercise intervention or a control group (=13), with 12 participants continuing with the intervention for 1.5 years. AT biomechanical properties were assessed using ultrasonography and dynamometry. Tendon cross-sectional area (CSA) was investigated by means of magnetic resonance imaging. A 22% exercise-related increment in ankle plantarflexion joint moment, along with increased AT stiffness (598.2±141.2 versus 488.4±136.9 N mm at baseline), Young's modulus (1.63±0.46 versus 1.37±0.39 GPa at baseline) and about 6% hypertrophy along the entire free AT were identified after 14 weeks of strength training, with no further improvement after 1.5 years of intervention. The aging AT appears to be capable of increasing its stiffness in response to 14 weeks of mechanical loading exercise by changing both its material and dimensional properties. Continuing exercise seems to maintain, but not cause further adaptive changes in tendons, suggesting that the adaptive time-response relationship of aging tendons subjected to mechanical loading is nonlinear.
衰老的肌肉骨骼系统在结构和功能上普遍衰退，其特征是对环境压力的适应能力下降。我们研究了老年人类跟腱（AT）在长期机械负荷作用下是否表现出机械敏感性（通过生物力学和形态学适应）。34名成年女性（60 - 75岁）被分配到中期（14周；n = 21）高AT应变循环负荷运动干预组或对照组（n = 13），其中12名参与者继续进行1.5年的干预。使用超声检查和测力计评估AT的生物力学特性。通过磁共振成像研究肌腱横截面积（CSA）。经过14周的力量训练后，发现踝关节跖屈关节力矩与运动相关的增加了22%，同时AT刚度增加（基线时为488.4±136.9 N·mm，训练后为598.2±141.2 N·mm），杨氏模量增加（基线时为1.37±0.39 GPa，训练后为1.63±0.46 GPa），并且整个游离AT的肥大约为6%，在1.5年的干预后没有进一步改善。衰老的AT似乎能够通过改变其材料和尺寸特性，在14周的机械负荷运动后增加其刚度。持续运动似乎能维持，但不会导致肌腱进一步发生适应性变化，这表明衰老肌腱在机械负荷作用下的适应性时间反应关系是非线性的。
