Investigation of Plantar Shear Stresses in Diabetic Patients: Relevance to Foot U

描述（由申请人提供）：糖尿病足溃疡继续给美国医疗保健系统造成负担，每年花费110亿美元，每年截肢率为10万。不幸的是，这个问题的确切病因仍有待解决。开发有效的鞋类和干预策略来预防糖尿病截肢需要对并发症途径的全面了解。众所周知，糖尿病足病变具有生物力学病理学，涉及足下作用的应力增加。然而，研究表明，单独的足部压力并不能很好地预测溃疡。这是因为溃疡可能发生在不被认为是有害的压力水平和不承受峰值压力的位置。初步研究表明，糖尿病足溃疡和剪切应力之间的关系，另一个机械成分，发生在脚-地界面。这些研究通过揭示糖尿病患者相对于对照组的剪切应力升高，而足部压力保持不变，证明了足底剪切的重要性。其他人的研究表明，摩擦剪切应力是造成老茧的原因，而老茧与糖尿病足病变的发生密切相关。剪应力的重要性源于这样一个事实，即它们基本上以两倍于脚底压力的时间频率起作用。据推测，糖尿病足创伤与下肢足底表面经历的高摩擦剪切力有关。与早期的初步研究不同，本研究将调查四组受试者的大样本足底剪切应力，以及足部病变与摩擦剪切应力之间的位置关系。本研究的第一个具体目的是调查和比较峰值剪切应力值，该峰值剪切应力值将通过定制的设备在153名受试者中获得。这些科目将包括；(a)有溃疡史的糖尿病神经病患者，(b)既往无溃疡的糖尿病神经病患者，(c)糖尿病对照患者和(d)健康个体。第二个具体目的将探讨是否以前的足溃疡发展的高峰剪切位置，在患者最近愈合的伤口。如果这种关联的存在得到证实，这些数据将为设计降低糖尿病足部伤口患病率的预防方法提供宝贵的信息。预防糖尿病足溃疡不仅会减轻美国医疗保健的经济负担，还会减轻易患并发症的糖尿病患者的生理和心理负担。

DESCRIPTION (provided by applicant): Diabetic foot ulcers continue to burden US healthcare system with an annual cost of $11 billion and yearly amputation rates of 100,000. Unfortunately, the exact etiology of the problem remains to be resolved. Developing effective footwear and intervention strategies to prevent diabetic amputations requires a comprehensive understanding of the complication pathway. Diabetic foot lesions are known to have a biomechanical pathology that involves increased stresses acting under the foot. However, studies have shown that foot pressure alone is not a good predictor of ulcerations. This is due to the fact that ulcers might occur at pressure levels that are not considered harmful and locations that do not bear peak pressures. Preliminary studies suggest a relationship between diabetic foot ulcers and shear stress, the other mechanical component, which occur at the foot-ground interface. These studies demonstrated the importance of plantar shear by revealing elevated shear stresses in diabetic patients with respect to control subjects, while foot pressures remained the same. Studies by others have shown that frictional shear stresses are responsible for creating calluses, which are known to be strongly associated with the occurrence of diabetic foot lesions. The significance of shear stresses arises from the fact that they fundamentally act with twice the temporal frequency of pressure under the foot. It is hypothesized that diabetic foot wounds are associated with high frictional shear forces experienced on the plantar surface of the lower extremity. Unlike earlier preliminary studies, this study will investigate plantar shear stresses in a large sample of subjects classified under four groups and a location-wise relationship between foot lesions and frictional shear stresses. The first specific aim of this study is to investigate and compare peak shear stress values, which will be obtained by a custom-built device in a total of 153 subjects. These subjects will include; (a) diabetic neuropathic patients with an ulcer history, (b) diabetic neuropathic patients without previous ulcers, (c) diabetic control patients and (d) healthy individuals. The second specific aim will explore whether previous foot ulcers developed at peak shear locations, in patients with recently healed wounds. If the presence of such an association is confirmed, these data will provide invaluable information in the design of preventive approaches to lower the prevalence of diabetic foot wounds. Prevention of diabetic foot ulcers will lift not only the financial burden on the US healthcare, but also the physical and psychological burden on diabetic patients who are vulnerable to complication. PUBLIC HEALTH RELEVANCE: Although the exact etiology of the diabetic neuropathic foot ulcerations is still not known, it is thought that these lesions are directly related with increased frictional shear forces under the diabetic foot. If the hypotheses of this study are confirmed, then the US healthcare system will realize substantial savings by the effective design of preventive devices and approaches aiming at reducing the prevalence of diabetic foot ulcers. Furthermore, diabetic neuropathic patients, who have to face the risk of losing their limbs, will be provided with greater physical and psychological comfort.