In vivo thickness and dynamic behaviour of the heel fat pad during ageing: biomechanical and anthropological impact of footwear.

足跟垫是介于足跟骨和皮肤之间的一种复杂结构，对于健康的步态具有重要的减震器作用，因此它影响着人们的生活质量。然而，在老化过程中，由于其机械性能的变化，它的这种能力会恶化。目前尚不清楚这些变化是由老化引起的，还是由过度使用引起的。前者无法改变，但后者可以通过几个因素减轻，包括鞋类。一个人对鞋子的选择通常取决于文化和设计，而不是功能——这被称为鞋子的生物力学——因此这些都是需要考虑的重要因素。这项跨学科的研究将把人类学的元素（什么是鞋类选择的文化和设计驱动因素？）与功能解剖学和生物力学结合起来。我们将收集实验室（英国）和现场（印度，纳米比亚）关于鞋垫性能的数据，并评估它们如何随着年龄和鞋类的变化而变化。我们将研究使用不同鞋类的年轻人和老年人，以解开年龄和鞋类习惯对鞋垫性能和步态的影响。英国先进的实验室设备将允许我们使用3D x射线视频记录来显示脚后跟垫在赤脚走路和穿鞋时是如何变形的：最小和有缓冲。我们还将使用MRI建立一个3D足部模型，包括脚后跟垫，记录腿和脚的运动，并测量基底与脚或鞋之间的力。我们将研究年轻人（18-40岁）和老年人（60岁以上）来回答以下问题：(1)足部功能和估计组织负荷的变化（使用有限元模型）如何与这些群体之间的鞋垫变化相关，以及(2)不同数量的鞋垫对当前的影响是什么？我们在印度的实地研究将解决这个问题：长期穿鞋的影响是什么？我们将通过比较每天穿鞋的参与者和从不穿鞋的参与者来回答这个问题-这是印度南部农村地区的一个相当大的亚人口。如果鞋子会影响鞋垫的退化，我们希望在年龄和其他因素相匹配的情况下，看到两组之间的差异。我们的纳米比亚研究将与来自San （Ju bbbbi’hoansi bushmen）社区的参与者合作，San （Ju bbbbi’hoansi bushmen）社区是地球上基因最多样化的人群之一。他们展示了一系列的鞋类习惯，从西式鞋子到土著狩猎凉鞋。它们也习惯在自然基质上行走。我们将调查鞋垫和步态之间的关系是否在人群中相似。我们还将试图了解我们的人群选择鞋子背后的一些原因。在所有研究中，我们将使用便携式超声成像来测量鞋垫的厚度和可压缩性，使用内部设计的应变测量设备来估计其机械性能，使用视频来测量步态，使用可穿戴数据记录仪来测量足部撞击和脚踝运动。我们将通过结构化访谈评估文化与功能驱动因素对鞋类选择的影响。综合起来，这些研究将使我们能够解开年龄和鞋类习惯对鞋垫性能和步态的影响，为理解鞋垫健康、衰老和生活质量的影响奠定基础。这些研究还将支持从主要以实验室为基础的西方生物力学向更加包容、多样化和跨学科的研究领域的转变。我们将开发新的知识，以确定哪种类型的鞋子可以防止鞋垫老化，以及具有单独调节缓冲的鞋子是否可以帮助减轻鞋垫质量的现有损失。这样做会使老年人的足部功能更好，步态更有效，生活质量更好。

The heel pad is a complex structure between the heel bone and the skin which is important as a shock absorber for healthy gait, and therefore it affects quality of life. However, its ability to do so deteriorates during ageing because its mechanical properties change. It is unclear whether these changes result from ageing as such, and/or from overuse. The former cannot be changed, but the latter can be mitigated by several factors, including footwear.An individual's footwear choice often depends on culture and design, more than on function - known as the shoe's biomechanics - and therefore these are important to consider. This interdisciplinary study will bring together elements of anthropology (what are cultural and design drivers in footwear choice?) with functional anatomy and biomechanics. We will collect laboratory (UK) and field (India, Namibia) data on the properties of the heel pad and assess how they change with ageing and footwear. We will study young and older populations with different footwear use to disentangle the effects of ageing and footwear habits on heel pad properties and gait. Access to sophisticated laboratory equipment in the UK will allow us to use 3D X-Ray video recordings to show how the heel pad deforms during walking barefoot, and in footwear: minimal and cushioned. We will also use MRI to build a 3D foot model including the heel pad, record the motions of the leg and foot, and measure the forces between the substrate and the foot or shoe. We will study a younger (18-40) and an older (60+) population to answer the questions: (1) how do changes in foot function and estimated tissue loading (using Finite Element Modelling) relate to heel pad changes between these groups, and (2) what are the here-and-now effects of various amounts of footwear cushioning?Our field study in India study will address the question: what is the effect of long-term use of footwear? We will answer this by comparing participants that wear shoes daily, to participants who never wear shoes - a considerable sub-population in rural parts of South India. If footwear affects heel pad degradation, we expect to see differences between the two groups, when matched for age and other factors.Our Namibia study will work with participants from the San (Ju|'hoansi bushmen) community, one of the most genetically diverse populations on earth. They display a range of footwear habits from Western-type shoes to indigenous hunting sandals. They also habitually walk on natural substrates. We will investigate whether the relationships between the heel pad and gait are similar between populations. We will also aim to understand some of the reasons behind footwear choice in our populations.In all studies, we will use portable ultrasound imaging to measure thickness and compressibility of the heel pad, an in-house designed strain measurement device to estimate its mechanical properties, video to measure gait, and a wearable data logger to measure foot strike impact and ankle movements. We will assess cultural versus functional drivers for footwear choice through structured interviews.Combined, these studies will allow us to disentangle the effects of ageing and footwear habits on heel pad properties and gait, laying a foundation for understanding the impact of heel pad health, ageing and quality of life. These studies will also support the transition from primarily lab-based, Western biomechanics to a more inclusive, diverse, and interdisciplinary research field. We will develop new knowledge to determine if, and what type of footwear can prevent deterioration of the heel pad during ageing, and if footwear with individually tuned cushioning can help mitigate existing loss in heel pad quality. Doing so will result in better foot function, effective gait, and better quality of life in older people.