个性化足跟痛缓冲鞋垫的生物力学研究

目的 研究带有不同结构后跟垫的个性化鞋垫对足跟痛患者足部应力集中的作用效果。方法 结合统计学和有限元分析方法，建立足跟痛患者足部及个性化鞋垫有限元模型，仿真模拟不同鞋垫对足跟痛患者足部软组织内外及足底筋膜应力的作用效果。结果 足部软组织内部所受应力高于足底表面，足底筋膜应力在第3根筋膜上的应力最高。裸足站立时足跟区软组织内部应力峰值是表面峰值的1.34倍，足底第3根筋膜的应力为1.50 MPa。通过正交试验得到的优化鞋垫模型能够降低足跟区软组织内部应力峰值51.0%，同时缓解足底第3根筋膜应力11.3%。结论 带有竖轴椭圆形、蜂窝状孔槽结构后跟垫的个性化缓冲鞋垫方案较优，后跟垫能辅助跟骨脂肪垫吸收或缓冲震荡，较好地减轻足底应力分布集中的同时具有缓解足底筋膜张力的作用。结果有助于认识足跟痛足部的应力分布情况，对研究足跟痛的病理和治疗具有重要的意义。
Objective To study the effect from personalized insoles with different structural heel pads on plantar stress concentration of patients with heel pain. Methods Base on statistics and finite element analysis method, the finite element model of foot and personalized insoles for patient with heel pain were established. The effects from different insoles on stress of soft tissues and plantar fascia were simulated. Results The internal stress of plantar soft tissues was higher than that of plantar epidermis, and the stress of the third plantar fascia was the highest. During barefoot standing, the internal peak stress of plantar soft tissues was 1.34 times of plantar epidermis, and the stress of the third plantar fascia was 1.50 MPa. The result of orthogonal experiment showed that the optimized insole model could reduce the internal peak stress of plantar soft tissues by 51%, meanwhile relieve the stress of the third plantar fascia by 11.3%. Conclusions The optimum scheme of personalized buffer insole is the design of vertical ellipse and honeycomb groove. Such structure can assist the absorption or buffering of concussion from calcaneal fat pad, and relieve the plantar stress concentration and tension of the plantar fascia. This study is helpful to understand plantar stress distributions of patients with heel pain, which is of great significance to the study of pathology and prevention of heel pain.