Gordon Ralph, Stevens Charlotte, Worsley Peter, Filingeri Davide
School of Health Sciences, Faculty of Environmental Life Sciences, University of Southampton, Southampton, United Kingdom.
JMIR Res Protoc. 2025 Jul 21;14:e73250. doi: 10.2196/73250.
Pressure in combination with shear forces can deform soft tissues and lead to development of pressure ulcers. The prevalence rate of pressure ulcers in the United Kingdom remains unacceptably high and can occur across the human lifespan. The posterior heel represents a common anatomical site for pressure ulcers due to soft tissues lying adjacent to bony prominences and being exposed to pressure and shear during lying postures. Localized cooling and interface materials that reduce shear may offer potentially therapeutic benefits in the development of pressure ulcers. Yet the physiological mechanisms underpinning the potential benefits of localized cooling are not fully understood.
This study protocol aims to investigate how localized cooling influences the skin's microvascular, inflammatory, structural, and perceptual tolerance to repeated shear loading at the heel.
The protocol will be tested on individuals of different age, sex, skin tone, and comorbidities, using a repeated measures design. Three cohorts will be recruited: (1) young and healthy (n=35), (2) older and healthy (n=35), and (3) with spinal cord injury (n=35). Participants will complete 3 testing sessions using a custom-built shearing rig with integrated thermal plate, during which the posterior aspect of the heel will be exposed to a standardized mechanical stimulus to elicit repeated pressure and shear loading. The experimental condition of each session will be determined by the temperature of the thermal plate, which will be set to either 36 °C (no cooling), 24 °C (mild cooling), or 16 °C (strong cooling). Continuous measurements will include kinetic coefficient of friction (CoF) and skin blood flow (via laser Doppler flowmetry; 40 Hz). Pro- and anti-inflammatory biomarkers in skin sebum (via Sebutape), structural skin properties (via optical coherence tomography), skin conductance (in microsiemens) and ratings of thermal sensation, comfort, and acceptance (via Likert scales) will also be assessed before and after the shear stress protocol.
Recruitment began in January 2024. As of February 2025, 43 participants had been enrolled in the study. Data collection and analysis are ongoing, and published findings are expected to be available in early 2026.
This analysis will help identify mechanisms of skin damage following repeated shear stress at the heel, furthering our understanding of superficial pressure ulcers. It will also establish physiological and perceptual thresholds for the protective effects of cooling from shearing-induced damage at the heel.
INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/73250.
压力与剪切力共同作用会使软组织变形，进而导致压疮的形成。英国压疮的患病率仍然高得令人无法接受，且在人的一生中都可能发生。足跟后部是压疮的常见解剖部位，因为此处软组织紧邻骨突，在卧位时会受到压力和剪切力的作用。局部降温以及能减少剪切力的界面材料可能对压疮的防治具有潜在的治疗益处。然而，局部降温潜在益处背后的生理机制尚未完全明确。
本研究方案旨在探究局部降温如何影响足跟皮肤对反复剪切负荷的微血管、炎症、结构及感知耐受性。
该方案将采用重复测量设计，在不同年龄、性别、肤色和合并症的个体中进行测试。将招募三组人群：（1）年轻且健康者（n = 35），（2）年长且健康者（n = 35），（3）脊髓损伤者（n = 35）。参与者将使用带有集成热板的定制剪切装置完成3次测试，在此期间，足跟后部将受到标准化机械刺激，以引发反复的压力和剪切负荷。每次测试的实验条件将由热板温度决定，热板温度将设置为36℃（无降温）、24℃（轻度降温）或16℃（强力降温）。连续测量将包括动摩擦系数（CoF）和皮肤血流量（通过激光多普勒血流仪；40Hz）。在剪切应力测试前后，还将评估皮肤皮脂中的促炎和抗炎生物标志物（通过皮脂胶带）、皮肤结构特性（通过光学相干断层扫描）、皮肤电导（微西门子）以及热感觉、舒适度和接受度评分（通过李克特量表）。
招募工作于2024年1月开始。截至2025年2月，已有43名参与者纳入该研究。数据收集和分析正在进行中，预计2026年初公布研究结果。
本分析将有助于确定足跟反复剪切应力后皮肤损伤的机制，增进我们对浅表性压疮的理解。它还将确定足跟剪切诱导损伤的降温保护作用的生理和感知阈值。
国际注册报告识别码（IRRID）：DERR1-10.2196/73250。
