The Role of Foot Structure and Function on Walking Mechanics and Energetics in Aging

项目摘要 老年人表现出推进发电的大幅减少。这种行走力学的变化 与较慢的步行速度和更大的代谢能量消耗有关-这些特征 影响独立性和生活质量。推进力的下降通常归因于 在行走的“蹬离”阶段减少踝关节机械功率。然而，加强小腿肌肉 对于提高蹬离强度、步行速度和/或代谢成本， 我们需要新的和可修改的目标，以保持我们老龄化人口的流动性。最近的研究 确定脚，独立于踝关节，在控制蹬离强度中起关键作用。的 主动结构（例如足部内的肌肉）和被动结构（例如足底）之间的相互作用 腱膜-一种跨越脚底的弹性结构）对于经济运动是至关重要的， 但目前还不清楚这种相互作用如何促进向前推进，或者这种相互作用如何随着年龄的变化而变化。 我们认为，年龄相关的变化，被动和主动的贡献，脚僵硬可能有助于 老年人蹬地强度的降低，直接通过足力的不足，间接通过 脚踝力量的滥用目标1：我们的提案将利用一种新的双探头超声成像 技术，以确定脚的刚度和足底内在肌肉收缩动力学的作用，在管理 年轻人的足踝相互作用动力学。目标2：然后，我们将描述当地的精力充沛， 通过紧密结合我们的实验数据， 从目标1到下肢的计算模型。目标3：最后，我们将确定 年龄对足部僵硬及其在步行经济性和功能性活动性中的作用。这项研究有可能 影响我们对年龄相关活动性的生物力学理解和临床管理的范式转变 损伤此外，我们的研究结果将对有针对性的移动干预机会产生直接影响。 创新设计可穿戴的集成式足部和脚踝设备， 改善我们老龄化人口的健康和福利。最后，我们的技术进步， 肌肉骨骼成像将彻底改变功能性运动行为期间体内超声的使用， 对人类和其他动物有着广泛的影响。

PROJECT SUMMARY Older adults exhibit a substantial reduction in propulsive power generation. This change in walking mechanics is associated with slower walking speeds and greater metabolic energy expenditure – features that negatively affect independence and quality of life. Age-related reductions in propulsive power are often attributed to reduced ankle mechanical power during the ‘push-off’ phase of walking. Yet, strengthening the calf muscles has been an ineffective strategy for improving push-off intensity, walking speed, and/or metabolic cost, motivating the need for new and modifiable targets for preserving mobility in our aging population. Recent studies have determined that the foot, independent of the ankle, plays a critical role in governing push-off intensity. The interaction between active structures (e.g. muscles within the foot) and passive structures (e.g. plantar aponeurosis – an elastic structure spanning the bottom of the foot) of the foot are vital to economic locomotion, but it is unclear how this interaction facilitates forward propulsion, or how this interaction is changed with age. We propose that age-related changes in passive and active contributions to foot stiffness may contribute to reductions in push-off intensity in older adults, both directly via deficits in foot power and indirectly via the misappropriation of ankle power. Aim 1: Our proposal will leverage a novel dual-probe ultrasound imaging technique to determine the role of foot stiffness and plantar intrinsic muscle contractile dynamics in governing foot-ankle interaction dynamics in young adults. Aim 2: We will then characterize the local energetic and mechanical response to changes in plantar aponeurosis stiffness by closely integrating our experimental data from Aim 1 into a computational model of the lower extremity. Aim 3: Finally, we will determine the effects of age on foot stiffness and its role in walking economy and functional mobility. This study has the potential to influence a paradigm shift in our biomechanical understanding and clinical management of age-related mobility impairment. Moreover, our findings will have immediate impact on targeted mobility intervention opportunities and innovation in the design of wearable integrated foot and ankle devices for enhanced mobility toward improving the health and welfare of our aging population. Finally, our technological advancements in musculoskeletal imaging will revolutionize the use of in vivo ultrasound during functional locomotor behavior, with broad implications in humans and other animals.