Mechanics of the Aging Achilles tendon with implications for walking performance

老化跟腱的力学对步行性能的影响

• 批准号: 8701027
• 负责人: Jason R Franz
• 金额: $ 5.46万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-06-01 至 2016-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8701027
• 关键词: Adhesions; Adult; Affect; Age; Aging; Ankle; Attention; Behavior; Biomechanics; Computational Technique; Computer Simulation; Data; Deterioration; Elderly; Exhibits; Faculty; Fascicle; Fellowship; Gait; Gastrocnemius Muscle; Generations; Goals; Health; Human; Image; Impairment; Individual; Isotonic Exercise; Lateral; Lead; Length; Measures; Mechanics; Medial; Methods; Modeling; Morphology; Motion; Muscle; Muscle Fibers; Muscle Weakness; Musculoskeletal; Output; Performance; Phase; Play; Positioning Attribute; Postdoctoral Fellow; Quality of life; Research; Role; Simulate; Skeletal Muscle; Slide; Soleus Muscle; Techniques; Tendon structure; Time; Tissues; Training; Triceps Brachii Muscle; Ultrasonography; Universities; Walking; achilles tendon; age effect; age related; crosslink; elastography; experience; improved; in vivo; innovation; middle age; muscle form; muscle strength; novel; programs; public health relevance; sarcopenia; simulation; skills; stem; transmission process; young adult

DESCRIPTION (provided by applicant): The pervasive decline in ankle power generation, even in otherwise healthy older adults, plays a central role in the deterioration of walking abilit with age. However, muscle strengthening alone generally fails to significantly improve the walking ability of older adults, suggesting that factors other than sarcopenia contribute to the decline in plantarflexor power with age. I propose to investigate the relevance of age-related changes in Achilles tendon mechanics and their implications for walking ability in older adults. The premise of this study is that the aging Achilles tendon exhibits altered in vivo behavior that greatly diminishes the ability to optimally coordinate the ankle plantarflexor muscles during the push-off phase of gait. Preliminary data suggest that the superficial and deep Achilles tendon fascicles exhibit distinctly different displacements, likely due to inter- fascicle sliding, which ay be critical for optimally coordinating the forces from the individual plantarflexor muscles. Moreover, these data show evidence that advancing age brings much more uniform tendon tissue motion, which may arise from inter-fascicle adhesions within the Achilles tendon. The overall hypothesis of this research is that greater fascicle adhesions within the Achilles tendon of older adults bring more uniform tendon deformations that reduce the capacity for optimally coordinating the individual plantarflexor muscles, thereby compromising plantarflexor power and thus gait performance. The approach utilizes novel advances in imaging biomechanics and computational modeling to investigate age-related changes in Achilles tendon mechanics and function, and to predict the ramifications for walking ability in older adults. Following are the specific aims. Aim 1 will use an advanced ultrasound elastography approach to determine if advancing age is accompanied by greater Achilles tendon strain uniformity, a potentially important factor to consider as a mechanism for age- related walking ability limitations. Aim 2 will use an innovative combination of ultrasound elastography and electrical muscle stimulation to reveal if greater fascicle adhesions within the Achilles tendon of older adults bring more uniform deformations between the deep and superficial portions of the tendon. Finally, Aim 3 will incorporate the findings from Aims 1 and 2 into muscle-actuated forward dynamic simulations to predict changes in plantarflexor function during walking in older adults. This research will investigate for the first time the age-related changes in localized Achilles tendon strain distributions (Aim 1), their underlying mechanisms (Aim 2), and the ramifications for walking ability in older adults (Aim 3). Successful completion of these aims will contribute to an enhanced scientific understanding of age-related declines in walking ability and point to specific opportunities where more appropriate therapies could prolong independence and thus enhance quality of life in older adults.

描述（由申请人提供）：即使在健康的老年人中，踝关节发电的普遍下降也在随着年龄的增长而恶化的行走中起着核心作用。但是，仅肌肉加强通常无法显着提高老年人的步行能力，这表明除肌肉减少症以外的其他因素会随着年龄的增长而导致plantarflexor功率的下降。我建议研究跟腱力学与年龄相关的变化的相关性及其对老年人的步行能力的影响。这项研究的前提是，衰老的致命肌肌腱在体内行为上表现出改变，这大大降低了在步态推断阶段，可以最佳地协调脚踝plotharflexor肌肉的能力。初步数据表明，浅表和深肌腱筋膜表现出明显不同的位移，这可能是由于束间滑动所致，这对于最佳地协调各个Plantarflexor肌肉的力至关重要。此外，这些数据表明，增长年龄会带来更多均匀的肌腱组织运动，这可能是由阿喀琉斯肌腱内的菲斯蒂粘附产生的。这项研究的总体假设是，老年人的致命肌腱内的更大的筋膜粘连带来了更均匀的肌腱变形，从而降低了最佳协调单个plantarflexor肌肉的能力，从而损害了plantarflexor的力量，从而损害了步态性能。该方法利用了成像生物力学和计算建模的新进展来研究跟腱力学和功能与年龄相关的变化，并预测老年人步行能力的后果。以下是具体目标。 AIM 1将使用先进的超声弹力图方法来确定年龄是否伴随着较大的跟腱菌株均匀性，这是一个潜在的重要因素，这是与年龄相关的步行能力限制的机制。 AIM 2将使用超声弹力图和电肌肉刺激的创新组合，以揭示老年人的致命肌肌腱内较大的筋膜粘附是否会在肌腱的深层和表面之间带来更均匀的变形。最后，AIM 3将将AIM 1和2的发现纳入肌肉分动的正向动态模拟中，以预测老年人步行过程中plotalflexor功能的变化。这项研究将首次研究与年龄相关的局部跟腱菌株分布（AIM 1），其潜在机制（AIM 2）以及老年人步行能力的后果（AIM 3）。这些目标的成功完成将有助于增强对年龄相关的步行能力下降的科学理解，并指向更合适的疗法可以延长独立性并从而提高老年人生活质量的特定机会。