Variability of Triaxial Plantar Loading in Diabetic Patients

 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和患者带来负担，估计每年的费用为300亿美元，截肢率为100，000。不幸的是，问题的确切病因仍有待解决。开发有效的鞋类和干预策略，以防止糖尿病截肢需要全面了解溃疡途径。已知糖尿病足病变具有生物力学病理，其涉及作用于足部下的机械应力。足部压力本身并不是溃疡的良好预测因素，因为溃疡可能发生在被认为无害的压力水平。关于足底剪切的病理影响的结果还没有定论。仅用于缓解峰值压力的预防性鞋类在预防溃疡方面效果甚微，这可归因于溃疡的确切病理学尚未解决的问题。关于溃疡的另一种理论认为，周围神经病变导致糖尿病患者足底负荷模式不变，因此可能导致组织压痛和破裂。健康的个体被证明可以改变他们的负荷模式，这可以防止区域范围内的组织压痛和疼痛。由于神经病变，糖尿病足的某些区域被认为会经历无法缓解的重复应力。长时间的重复可能导致组织失效，即使是在较低但未减轻的机械应力下。较高的足底温度也与溃疡的发展有关。在跑步机上走10分钟会使健康的脚的温度大幅上升。由于足底应力较高，糖尿病患者的这种增加可能会更高，但尚未对此进行研究。步行引起的足底温度升高已被用作三轴足底负荷的预测因子。然而，这一假设尚未得到证实。为了验证这些假设，我们的目的是：（1）调查糖尿病神经病变患者三轴足底负荷的变异性，（2）比较三轴足底负荷的变异性， 神经病组和两个对照组之间的负荷，和（3）量化应力诱导的足底温度升高并将其与足底应力相关联。对于特定目标1，将在一天中的不同时间点收集糖尿病患者的足底压力和剪切曲线。如果在糖尿病患者中证实了不变的应激特征，则该因素将被视为溃疡的风险。对于具体目标2，我们将使用相同的方法来评估糖尿病神经病变受试者和对照受试者的三轴足底负荷的变异性。将比较三个受试者组之间的各阶段变异性。神经病受试者中显著不同的（较低的）变异性将表明这一点的临床重要性。 溃疡的因素。对于具体目标3，我们将量化受试者组中由于长时间行走而导致的足底温度升高。这种温度升高将与三轴足底应力大小相关。根据本研究中获得的信息，可以开发更有效的预防设备和策略来减少溃疡发生率。

 DESCRIPTION (provided by applicant): Diabetic foot ulcers continue to burden the US healthcare system and patients with an estimated annual cost of $30 billion and 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 ulceration pathway. Diabetic foot lesions are known to have a biomechanical pathology that involves mechanical stresses acting under the foot. Foot pressure alone is not a good predictor of ulcers, since ulcers might occur at pressure levels that are not considered harmful. Results regarding the pathological effects of plantar shear are not yet conclusive. Preventive footwear, designed to only relieve peak pressures are just meagerly effective in preventing ulceration which can be attributed to the fact that exact pathology of ulcers has unresolved issues. An alternative theory regarding ulceration states that peripheral neuropathy leads to unvarying patterns of plantar loading in diabetic patients, which may consequently result in tissue tenderness and breakdown. Healthy individuals were shown to shift their loading patterns, which prevents tissue tenderness and pain at the regional scale. Due to neuropathy, certain regions of the diabetic foot are thought to experience repetitive stresses that are not relieved. Prolonged repetition might result in failure of the tissue even wit lower, yet unrelieved, mechanical stresses. Higher plantar temperatures are also associated with ulcer development. Treadmill walking for 10 minutes leads to a substantial temperature increase in healthy feet. This increase can possibly be higher in diabetic patients due to higher plantar stresses, which has not been yet studied. Walking-induced plantar temperature increase has been used as a predictor of triaxial plantar loading. However this hypothesis has not been validated. In order to test these hypotheses, we aim at; (1) investigating the variability of triaxal plantar loading in diabetic neuropathic patients, (2) comparing the variability of triaxial plantar loading between the neuropathic group and two control groups, and (3) quantifying stress-induced plantar temperature increase and correlating this with plantar stresses. For specific Aim 1, plantar pressure and shear profiles of diabetic patients will be collected at different time points during a day. If unvarying stress profiles are confirmed in diabetic patients, this factor wll be considered as a risk for ulceration. For specific aim 2, we will use the same methodology to assess the variability of triaxial plantar loading in diabetic neuropathic and control subjects. Variability across sessions will be compared between the three subject groups. Significantly different (lower) variability in neuropathic subjects will indicate the clinical importance of this factor in ulceration. For specific aim 3, we will quantify plantar temperature increases due to prolonged walking in subject groups. This temperature increase will be correlated against triaxial plantar stress magnitudes. Based on information acquired in this study, more effective preventive devices and strategies may be developed to reduce ulcer incidences.