Tenenbaum Shay, Shabshin Nogah, Levy Ayelet, Herman Amir, Gefen Amit
Department of Orthopaedic Surgery, Sheba Medical Center, Tel Aviv, Israel.
J Rehabil Res Dev. 2013;50(8):1149-56. doi: 10.1682/JRRD/2012.10.0183.
Heel ulcers (HUs) are the second most common pressure ulcers (PUs). Despite the significant morbidity and economic cost associated with HUs, there remains a lack of understanding of the basic pathophysiology of PUs because of limited basic research. There are only sparse data regarding the efficacy of prevention aids such as heel padding devices, and these data are based mainly on epidemiological research rather than biomechanical models and deformation measurements. This study was designed to explore the effects of foot posture and support stiffness properties on soft tissue deformations using magnetic resonance imaging (MRI). Subjects were scanned with and without weight bearing, in neutral external rotation position and in 90 degrees to supporting surface and with different heel padding devices. Tissue strains were calculated for skin, subcutaneous tissue, and effective (total) soft tissue. We found skin strains with the foot in external rotation to be significantly greater than when the foot was upright. Heel padding devices have a statistically significant effect on reducing the extent of deformations in both skin and subcutaneous tissues. Furthermore, the design features of heel padding devices have substantial influence on tissue deformations. This study demonstrates how MRI provides convenient, accurate, and quantitative comparison of biomechanical performances of heel padding devices.
足跟溃疡（HUs）是第二常见的压疮（PUs）。尽管HUs会导致严重的发病率并产生经济成本，但由于基础研究有限，人们对压疮的基本病理生理学仍缺乏了解。关于足跟垫等预防辅助器具的功效，仅有稀少的数据，且这些数据主要基于流行病学研究，而非生物力学模型和变形测量。本研究旨在利用磁共振成像（MRI）探索足部姿势和支撑刚度特性对软组织变形的影响。在负重和非负重状态下，以外旋中立位、与支撑面呈90度角以及使用不同足跟垫的情况下对受试者进行扫描。计算皮肤、皮下组织和有效（总）软组织的组织应变。我们发现足部外旋时的皮肤应变显著大于足部直立时。足跟垫对减少皮肤和皮下组织的变形程度具有统计学上的显著效果。此外，足跟垫的设计特点对组织变形有重大影响。本研究展示了MRI如何为足跟垫的生物力学性能提供便捷、准确和定量的比较。
