Relationship between plantar pressure distribution under the foot and insole comfort

In this paper, four pairs of insoles with different comfort characteristics were used to investigate the relationship between the pressure distribution under the foot and running shoe comfort. Fourteen male subjects were tested in four insole conditions by walking and running on a treadmill. The pressure at the plantar surface of the foot was measured by using an EMED pressure-measuring insole. For walking there were significantly higher pressures and forces in the midfoot area and significantly lower pressures in the medial forefoot and hallux area by wearing the most comfortable insole compared with wearing the least comfortable insole. The shift of the pressure from forefoot to midfoot for the most comfortable insole provided an even distribution of the pressure at the plantar surface of the foot. The results also demonstrated that the path of centre of force at the plantar surface of the foot moved to the lateral aspect of the foot for the most comfortable insole. For running, only the pressure in the medial forefoot area was found significantly lower for the most comfortable insole than for the least comfortable insole. The results of this study indicated that the pressure distribution between the plantar surface of the foot and the shoe could detect the change of shoe comfort. Thus it is a suggestion that pressure measurement may be related to understand factors important for shoe comfort.

Comfort of sport shoes is important for the appropriate execution of sport activities. Additionally, comfort may influence fatigue and possibly the development of injuries. The quantification of comfort of sport shoes and the understanding of mechanical and/or biological functions related to it may be enhanced with the use of pressure measurements between the plantar surface of the foot and the shoe sole.     

Electronic measurement of plantar contact area during walking using an adaptive thresholding method for Medilogic® pressure-measuring insoles

BackgroundPressure-measuring insoles have the potential to measure plantar contact area (PA) during walking. However, they are not widely used for this purpose because of the need for a reliable process that can convert the insole output into PA. The purposes of this study were to: (1) develop an adaptive-threshold method for pressure-measuring insoles that can improve the accuracy of the PA measurements during walking, and (2) experimentally assess the accuracy and generalizability of this method.MethodsA sample of 42 healthy, ambulatory, young adults (age = 24.3 ± 3.2 years, mass = 67.2 ± 16.9 kg, height = 1.63 ± 0.08 m) completed 10 trials walking on an elevated walkway while wearing Medilogic^® pressure-measuring insoles (sizes 35–45). A total of six insole sizes were considered. Insole data were converted to PA using three unique adaptive-thresholds that were based on percentages of the maximum sum of digital values (MSDV) during an analyzed step. Three values were considered: 0.1%, 0.2%, and 0.3% of the MSDV. Additionally, a fixed-threshold, which is typically used to estimate PA, was assessed. These two techniques, applied to the insole worn on the left foot, were compared with PA obtained from high-resolution reference footprints obtained from optical pedography of the right foot and processed using digital image processing algorithms. An assumption of PA symmetry between the left (insole) and right (barefoot) feet was made and comparisons were conducted over the entire stance phase of walking. The generalizability of the algorithm was assessed by comparing PA errors from insoles with respect to the optical pedography results based on insole size criteria.ResultsThe adaptive-thresholds of 0.1%, 0.2%, and 0.3% of MSDV produced mean errors of 7.31 ± 17.44%, −8.62 ± 15.01%, and −20.45 ± 14.18%, respectively. Using the 2-digital value fixed-threshold produced a mean error of 20.88 ± 22.44%. The best performing adaptive-threshold varied among insole sizes.ConclusionIt was observed that the fixed-threshold technique produced large magnitudes of errors. The proposed adaptive-thresholds of 0.1% and 0.2% of the MSDV reduced PA error to ±10% during walking. The adaptive-threshold method consistently reduced PA error vs. the fixed-threshold for each insole size.     

Influence of using knee sleeve and lateral wedge insole on knee loading among healthy individuals during stair negotiation

BackgroundFor individuals with knee osteoarthritis (OA), stair negotiation is a challenging task and the first task during which they report pain due to the high knee loading required. The use of lateral wedge insole (LWI) has been found to reduce loading in patients with OA but not to reduce pain, whereas the use of knee sleeve has been shown to result in good pain reduction. Understanding the effect of combining LWI and knee sleeve use on healthy individuals before testing on individuals with knee OA is an important step.Research questionThe current study aimed to evaluate the effect of combining the use of LWI and knee sleeve and compare the results with the application of each treatment separately and with the control condition.MethodsThis randomised cross-over study included 17 healthy participants who underwent 3D gait analysis. Participants performed ascending and descending stair activities with the following four treatment conditions: five-degree LWI, off-the-shelf knee sleeve, both LWI and knee sleeve and control condition. External knee adduction moment (EKAM) and knee frontal plane range of motion (ROM) were evaluated as primary outcomes. Repeated measure ANOVA or the Friedman test was selected based on meeting the assumption followed by multiple pairwise comparisons with Bonferroni correction.ResultsIn general, the use of LWI reduced the first peak EKAM significantly (p < 0.001) compared to the control condition in stir ascending (12% reduction) but not in stair descending (p > 0.05). Interestingly, knee sleeve use did not result in any reduction in the first peak EKAM compared to the control or any other condition. However, knee sleeve use led to a significant reduction in the knee frontal plane ROM during stair descending. The combined treatment was not superior to the LWI use when compared to control in the EKAM reduction.SignificanceCombined knee sleeve and LWI use was not superior to LWI use alone in reducing the knee loading, but it may be beneficial for individuals with knee OA since it helped in reduction of the knee frontal plane ROM during stair descending. Importantly, the effect of LWI use or any other treatment must be investigated for each different activity, and the results found in one activity must not be generalised across other activities.     

具有分区域梯度硬度结构的定制减压鞋垫设计

目的针对高弓足等有足底减压需求的人群,设计一种具有分区域梯度硬度的定制化鞋垫。方法设计一种功能梯度结构,应用于定制化鞋垫,使鞋垫不同区域具有梯度变换趋势的硬度特征。通过力学试验,研究结构单元参数和模量之间的关系。采集志愿者足部几何形状和足底压力分布数据,根据压力等高线对足底区域进行划分,以此组装结构单元。设计4种定制化鞋垫:普通平板鞋垫、优化平板鞋垫、普通全接触鞋垫、优化全接触鞋垫。通过熔融沉积成型(fused deposition modeling,FDM)打印,再进行足底压力测试实验,验证分区域的优化设计。结果所设计的鞋垫可使高弓足测试者足部峰值压力在静态站立、步态状态下分别降低52.8%、18.43%。结论该方法可用于设计定制鞋垫,如针对糖尿病足、高弓足的功能鞋垫,提供更好的减压功能。研究结果为临床保守治疗有减压需求的足部疾病提供参考。     

Changes in plantar pressure and spatiotemporal parameters during gait in older adults after two different training programs

BackgroundImproving gait is in exercise programs for older adults (OAs) but little is known about how different gait-training approaches affect spatiotemporal parameters and plantar pressure distributions in OAs. High plantar pressures are linked to tissue injury risk, ulceration, and pain in OAs, but no studies have yet compared how they affect podobarometric variables.Research questionThe effect of changing plantar pressure on absolute and mean maximum pressure, the pressure-time integral, stride time, stance time, and gait speed in OAs following either a multicomponent training program (EG) or interval-walking training (WG).MethodsComfortable gait speed, strength (seat-to-stand test), and plantar pressure (Pedar-X mobile in-shoe system), were evaluated in 23 OAs (EG: n = 12, 7 female, 71.58 ± 4.56 years; WG: n = 11, 6 female, 69.64 ± 3.56 years), by dividing the plantar area into 9 regions.ResultsAfter 14 weeks, the maximum pressure in medial and central metatarsus areas in the dominant leg were reduced in the EG (p = 0.01 & p = 0.04, respectively), but increased in the non-dominant leg lateral heel in the WG (p = 0.03). The mean maximum pressure also increased in the WG in medial heel in the dominant leg (p = 0.02) and lateral heel in the non-dominant leg (p = 0.03). The overall pressure-time integral reduced in the whole plantar area in both legs in both groups. WG reduced stride time (dominant: p = 0.01; non-dominant: p = 0.01) and stance time (dominant: p < 0.005; non-dominant: p < 0.005). Gait speed did not change in any group. As expected, lower limb strength improved after both exercise programs (EG: p = 0.02; WG: p = 0.01).SignificanceAlthough these training interventions were short, they indicate the importance of exercise types. Our results suggest that OAs might benefit from periodized training, especially when multicomponent programs are introduced prior to the walking goals. Future, larger studies should explore situations in which special populations with specific foot problems might benefit from these interventions.     

个性化鞋垫对步行足部感知及足功能的影响

目的 通过对主观舒适度和行走时足底压力的评测,整合主观感知和生物力学指标,探究个性化鞋垫对正常足型足部感知和足功能的影响。方法 招募16名具有正常足型的男性受试者,采用视觉模拟量表评价极简鞋和个性化鞋垫着鞋干预下主观舒适度指标的差异;通过单因素重复测量方差分析赤足、极简鞋、个性化鞋垫3种着鞋条件支撑期各阶段时间和足底压力的变化;通过多重线性回归筛选极简鞋和个性化鞋垫下影响着鞋总体舒适性的主要指标。结果 在足底压力测评上,着鞋行走的步态支撑期缓冲阶段高于赤足和极简鞋（P<0.05）,个性化鞋垫的动态足弓指数（arch index, AI）大于极简鞋和赤足行走（P<0.05）,极简鞋动态 AI大于赤足（P<0.05）,加入个性化鞋垫中足冲量占比高于赤足行走（P<0.05）,着鞋时压力中心(center of pressure, COP）轨迹的平均斜率低于赤足（P<0.05）,个性化鞋垫COP轨迹斜率低于极简鞋（P<0.05）;在主观舒适度测评上,加入个性化鞋垫后鞋总体舒适性、后跟缓冲、前足缓冲、足弓支撑性、前足包裹和足部控制性高于极简鞋（P<0.05）;线性回归结果显示,足弓支撑性和中足冲量占比对鞋总体舒适性有显著性影响（P<0.05）。结论 个性化鞋垫主要通过对足弓的影响提高正常足的总体舒适性。加入个性化鞋垫后,步行的缓冲能力和足部控制能力提高,足部在冠状轴上受力的偏移减小。足-鞋垫-鞋共同影响人体足部感知,鞋垫要综合足型、着鞋条件和鞋垫材质等多方面进行选择。     

不同硬度楔形鞋垫对膝关节内翻力矩的影响

目的研究不同硬度楔形鞋垫在步行状态下对膝关节内翻力矩的影响。方法 15名健康成年男性受试者穿着不同硬度楔形鞋垫进行步态测试,通过光学运动捕捉系统和地面测力板收集运动学和动力学数据,经Visual3D软件计算得出膝关节内翻力矩,分析在3种不同步行状况下(仅穿鞋、鞋中放入软、硬楔形鞋垫)膝关节内翻力矩峰值的差异。结果与较软的楔形鞋垫相比,较硬的楔形鞋垫可使膝关节内翻力矩的第1个峰值降低9.3%,第2个峰值降低9.7%,差异具有统计学意义。结论楔形鞋垫增加一定的硬度能更多降低膝关节内侧间室的压力,减轻关节面的磨损,从而可能缓解膝关节炎症状。     

体外冲击波联合矫形鞋垫治疗足底筋膜炎的疗效观察

目的：观察体外冲击波联合矫形鞋垫治疗足底筋膜炎的疗效。方法：将153例足底筋膜炎患者随机分成 联合组(n=51)、冲击波组(n=53)和矫形组(n=49)。联合组采用体外冲击波联合矫形鞋垫治疗,冲击波组采用体外冲 击波治疗,矫形组采用矫形鞋垫治疗。比较患者治疗前和治疗后2周、1个月、3个月视觉模拟评分法(visual analogue scale,VAS)评分和持续行走时间、疗效及足底筋膜厚度。结果：3组治疗后VAS评分均较治疗前降低(P<0.05);2周时 冲击波组高于矫形组,2周和3个月时联合组低于矫形组(P<0.05);1个月、3个月时矫形组与联合组均低于冲击波组 (P<0.05);3组治疗后行走时间较治疗前明显提高,足底筋膜明显变薄(P<0.05);联合组的治愈率、总有效率明显高于 其它两组,矫形组的治愈率高于冲击波组(P<0.05)。结论：体外冲击波联合矫形鞋垫治疗足底筋膜炎疗效确切,值得 在临床上推广应用。     

Immediate Efficacy of Laterally Wedged Insoles With Arch Support on Walking in Persons With Bilateral Medial Knee Osteoarthritis

ObjectiveTo investigate the immediate efficacy of laterally wedged insoles with arch support (LWAS) on gait in persons with bilateral medial knee osteoarthritis (OA).DesignA prospective case-control intervention study.SettingA gait laboratory with a 6-camera motion analysis system and 2 forceplates.ParticipantsFifteen women with bilateral medial knee OA and 15 healthy control subjects (N=30).InterventionsLWAS.Main Outcome MeasuresSubjective knee pain and objective biomechanical indices, namely, joint angles and moments in the frontal plane, frontal plane ground reaction force and lever arm, as well as medial/lateral center of mass and center of pressure during gait.ResultsWhen wearing the LWAS, knee pain during gait in persons with medial knee OA decreased (P=.01). Peak internal knee abductor moments were also reduced (P<.001) with increasing foot progression angles, laterally shifted center of pressure, and a shortened frontal plane lever arm (all P<.05). However, ankle invertor moments were increased (P<.05) when wearing the LWAS.ConclusionsAlthough peak internal knee abductor moment and knee pain were immediately reduced during gait when wearing the LWAS, increased ankle invertor moments were found, suggesting that the LWAS should be used with caution. Strengthening and monitoring the condition of the ankle invertor muscles may be necessary if the LWAS is used as an intervention for persons with bilateral medial knee OA.