Figure - uploaded by Ulla Hellstrand Tang
Content may be subject to copyright.
Insoles and shoes. A) The contours of the custom-made insoles composed of ethylene vinyl acetate (EVA) with a standardized metatarsal bar. B) Prefabricated insole GloboTec® Comfort 312750501400 (GloboTec, Bauerfeind, Germany), with support of the medial arch and a metatarsal pad in the forefoot in a material with a core (reinforcement element) that consists of a mixture of thermoplastic, polyurethane, polyester, and polycarbonate. The cushioning material is foam that belongs to the chemical family of urethane polymers with a shore density of about 12 shore A. The cover is a 2-mm layer of microfiber, consisting of polyester and polyurethane. C) Photograph of a representative walking shoe used in the study (Opara Deluxe men 809159, ladies 8807159; Erimed, Stockholm, Sweden). The shoe has a semi-rigid outer sole, a stable heel counter, and adjustable lacing. The maximum height of the toe box is 40 mm vs. 43 mm for EUR size 38/Women last vs 45/Men last. D) An example of a custom-made insole that is ready to be exchanged due to the presence of cracks and breakdown areas.
Source publication
Background: Special insoles and shoes designed to prevent foot ulcers caused by repetitive high pressures are recommended for patients with diabetes who have any of the following risk factors: neuropathy; peripheral vascular disease; foot deformities; previous ulcers; amputation; and skin pathologies. However, there is a need for increased knowledg...
Contexts in source publication
Context 1
... heating and vacuum formation of the 14-mm-thick EVA material followed the distributor's recommendations (E603442, E603402; Össur Nordic, Uppsala, Sweden). Patients in the control group received prefabricated insoles (GloboTec Ò Comfort 312750501400; Globo- Tec, Bauerfeind, Germany) (Figure 1). One technician fabricated all the individual insoles with a standardized metatarsal bar proximal to metatarsal heads IIeIV. ...Context 2
... insoles were adjusted to fit into the participant's shoes, which were designed to be used outdoors. All the shoes had a semi-rigid outer sole or stiff rocker bottom, a stable heel counter, and adjustable laces or Velcro straps (Figure 1). Upon manufacturing, the shoes were checked, to ensure that they met all the set criteria. ...Context 3
... adjustments to the insoles during the study period were registered in the cate- gories of: higher or lower metatarsal bar; more lateral or medial support; and more material under the heel. New insoles were supplied when any cracks or breakdown areas in the insoles were detected at follow-up (Figure 1). At baseline, the self-reported status was recorded, which included the duration of diabetes, type of diabetes, glycated hemoglobin (HbA1c) level, use of medi- cation, use of nicotine, and ability to walk normally (yes/no). ...Context 4
... maxPP is the highest pressure sensed within each of the seven ROI over the same number of footsteps. The calculation PTI followed the equation: where P1 is the total pressure present in the first frame of the stance, T1 is the duration (time) of the first frame of the stance, PN is the total pressure present in the last frame of the stance, and TN is the duration of the final frame of the stance (from F-Scan User Manual 6.62, Rev H). Stance number 3 was selected for the analysis of PTI, as measured in kiloPascals  second. ...Context 5
... reduction in the heel region is probably due to the casting procedure, which entails tight molding that follows the contour of the heel. A three-dimensional view of a custom-made insole (Figure 1) shows a narrow heel width together with high edges, which retain the heel pad under the bony prominences of the calcaneus, thereby providing cushioning. Thus adjusting the prefabricated insoles with higher edges that are positioned tight to the heel can be assumed to improve the pressure reduction properties. ...Citations
... Pressure measurement systems have numerous applications in healthcare. The most common use is in clinical gait analysis to assist in the prescription and assessment of interventions such as orthotics [1][2][3][4][5][6][7][8][9][10][11], surgery [12][13][14][15][16][17], medication [18] or rehabilitation programmes [19][20][21][22][23]. They can also be used to provide biofeedback if pressure mapping data is linked to a live display [24][25][26][27], and can therefore alert patients and clinicians if patients' plantar pressures are too high, so the patient or clinician can offload the area of high pressure, reducing the risk of pressure ulcers forming [27]. ...
... In-shoe systems are thus often used to assess dynamic sporting movements, and are particularly suited to measuring plantar pressures during running [29,31,[122][123][124][125]. As these systems fit within the shoe, they are very suitable for applications such as assessing the effect of different types of footwear on plantar pressure [4,46,49,51,75,95,103,[126][127][128][129][130][131][132], measuring plantar pressures inside sport-specific footwear [34,35,62,133,134] and helping to prescribe and assess the effect of orthotics in redistributing or reducing plantar pressures [9][10][11][135][136][137][138]. ...
Pressure measurement systems have numerous applications in healthcare and sport. The purpose of this review is to: (a) describe the brief history of the development of pressure sensors for clinical and sport applications, (b) discuss the design requirements for pressure measurement systems for different applications, (c) critique the suitability, reliability, and validity of commercial pressure measurement systems, and (d) suggest future directions for the development of pressure measurements systems in this area. Commercial pressure measurement systems generally use capacitive or resistive sensors, and typically capacitive sensors have been reported to be more valid and reliable than resistive sensors for prolonged use. It is important to acknowledge, however, that the selection of sensors is contingent upon the specific application requirements. Recent improvements in sensor and wireless technology and computational power have resulted in systems that have higher sensor density and sampling frequency with improved usability - thinner, lighter platforms, some of which are wireless, and reduced the obtrusiveness of in-shoe systems due to wireless data transmission and smaller data-logger and control units. Future developments of pressure sensors should focus on the design of systems that can measure or accurately predict shear stresses in conjunction with pressure, as it is thought the combination of both contributes to the development of pressure ulcers and diabetic plantar ulcers. The focus for the development of in-shoe pressure measurement systems is to minimise any potential interference to the patient or athlete, and to reduce power consumption of the wireless systems to improve the battery life, so these systems can be used to monitor daily activity. A potential solution to reduce the obtrusiveness of in-shoe systems include thin flexible pressure sensors which can be incorporated into socks. Although some experimental systems are available further work is needed to improve their validity and reliability.
... Plantar pressure data were collected at 100 Hz using the Tekscan system (Wireless Tekscan Device, Boston, MA, USA) and analyzed using the F-Scan software (F-Scan Research 4.5) [9,[24][25][26]. The footprint was divided into 13 plantar foot regions to analyze the plantar pressure data. ...
This study aimed to investigate the effect of varying the hardness of prefabricated orthopedic insoles on plantar pressure and muscle fatigue during uphill walking with a heavy backpack. Fifteen healthy male recreational athletes (age: 20.4 ± 1.0 years, height: 176.9 ± 5.7 cm, weight: 76.5 ± 9.0 kg) wore prefabricated orthopedic insoles with foot arch support; a heel cup with medium (MI), hard (HI), and soft (SI) relative hardnesses; and flat insoles (FI). They performed treadmill walking on uphill gradients with 25 kg backpacks. The plantar pressure and surface electromyographic activity were recorded separately, in 30 s and 6 min uphill treadmill walking trials, respectively. The HI, MI, and SI significantly decreased peak plantar pressure in the lateral heel compared to FI. The MI and SI significantly decreased the peak plantar pressure in the fifth metatarsal compared to FI. The MI significantly reduced the pressure–time integral in the lateral heel compared to FI. The HI significantly increased the peak plantar pressure and pressure–time integral in the toes compared to other insoles, and decreased the contact area in the metatarsal compared to SI. In conclusion, a prefabricated orthopedic insole made of soft material at the fore- and rearfoot, with midfoot arch support and a heel cup, may augment the advantages of plantar pressure distribution during uphill weighted walking.
... The current reliability study was based on plantar pressure measurements in a cohort of PDs, from a 10-year follow-up study of the use of three different types of insole (Hellstrand [20]). At study start in 2008, the in-shoe pressure measurement was obtained using F-Scan® 6.10 software, while, at the 10-year follow-up, an upgraded version, F-Scan® 7.50 (Tekscan, Boston, MA, USA), was used. ...
... Not surprisingly, the intra-reliability was higher 86% (12 of 14 positions) for the positions with excellent or good intrareliability. The ICC of box placements for the midfoot region was low, similar to findings by Vidmar et al. [19] and Hellstrand et al. [20]. In this area, some individuals have a more pronounced lateral arch, the cavus feet, with less contact with the ground. ...
... One strength in the current study was that the observers were skilled and followed a structured protocol. The data that were analysed were collected in stable conditions at the same gait lab with the same regimen as when the study started [20]. The authors strongly recommend that clinicians who consider using the F-Scan® system should train the placement of the TAM boxes before in-shoe pressure measurements are used in clinical practice to evaluate the effects of pressure-reducing orthotics. ...
Background:
The provision of therapeutic footwear, to prevent the development of diabetic foot ulcers by re-distributing high peak plantar pressure is frequently prescribed for patients with diabetes. Areas of interest (ROI) are identified by placing boxes on the visualised pressure movie. The aims were to evaluate the inter-reliability of the placements of seven ROI boxes and to explore how the box placement affected peak pressure in the seven ROIs.
Methods:
Plantar pressure movies from 20 of a total of 40 movies were selected for the analysis. Boxes were placed at ROIs, the heel, the lateral midfoot, the metatarsal phalangeal heads (5, 3-4, 2 and 1) and the hallux. The box placements were registered for the left vertical position (L) and the top horizontal position (T) for each of the ROIs, based on registrations by two certified prosthetists and orthotists.
Findings:
The inter correlation coefficient of the placement of the boxes ranged from 1.00 to 0.12 (heel_L and metatarsal phalangeal head 2_L respectively). Of the 14 positions of the boxes; four were excellent, four were good, two were moderate and four were poor. No significant differences in the mean peak pressure corresponding to the box placements were found between the CPOs.
Interpretation:
The inter-reliability of eight of the 14 registered placements, made by prosthetists and orthotists, of the boxes in Scan® was good to excellent. A variation of 1.00-0.12 was present. Despite the variation, no significant differences in the corresponding mean peak pressure between prosthetists and orthotists was found.
... The Poisson's ratio values were available with the manufacturers which had tested these materials based on several tensile and compressive tests. In a recent study by Tang et al. [40], EVA was used as an insole material to evenly distribute the plantar pressures across the diabetic population. In another study by Viswanathan et al. [41], different insole materials were tested for their effective distribution of foot pressures. ...
Daily activities such as walking and running possess abundant amount of energy, which is usually wasted and have the potential to be harvested. Especially, the energy generated from footsteps, if tapped appropriately, may be useful for charging electronic devices such as cell phones, wearables, and medical devices. In this study, the kinetic energy from footsteps was captured using a novel six-layered compartmental insole design with embedded piezoelectric transducers. This system was fabricated using additive manufacturing techniques and evaluated for its capabilities to charge a battery while walking and running. The charging performance was estimated initially for 6000 walking steps and extended to approximately 67,000 simulated running steps to fully charge the battery. A range of transducer arrangements were tested, indicating better power generation from the parallel combinations compared to series. Across gait activities, running was observed to lead to better coordination between the piezoelectric transducers and generation of higher power, compared to in walking. While very high amount of electrical power was not realized, the device performance was found to be satisfactory to charge low power rated wearable lifestyle electronic or medical devices. The findings from this work is anticipated to provide novel insights for power harvesting from human gait.
... A medium-density Ethylene-vinyl acetate (Md-EVA) (Swastik Polymers, New Delhi, India), of 0.5 mm thickness, was also used. In a recent study by Tang et al. [38], EVA was used as an insole material to evenly distribute plantar pressure across the diabetic population, for added comfort. In another study by Viswanathan et al. [39], different insole materials were tested for their effective distribution of foot pressure: compared to other materials, EVA was found, across the volunteers, to provide added comfort more conveniently. ...
Foot-related problems are prevalent across the globe, and this issue is aggravated by the presence of diabetes mellitus. Diabetic-foot-related issues include extreme foot pain, plantar corns, and diabetic foot ulcers. To assess these conditions, accurate characterization of plantar pressure is required. In this work, an in-shoe, low-cost, and multi-material pressure measuring insole, based on a piezoresistive material, was developed. The device has a high number of sensors, and was tested on 25 healthy volunteers and 25 patients with different degrees of diabetes. The working range of the device was observed to be 5 kPa to 900 kPa, with an average hysteresis error of 3.25%. Plantar pressure was found to increase from healthy to diabetic volunteers, in terms of both standing and walking. In the case of the diabetic group, the-high pressure contact area was found to strongly and positively correlate (R2 = 0.78) with the peak plantar pressure. During the heel strike phase, the diabetic volunteers showed high plantar pressure on the medial heel region. In regard to the toe-off phase, the central forefoot was found to be a prevalent site for high plantar pressure across the diabetic volunteers. The developed device is expected not only to assist in the prediction of diabetic ulceration or re-ulceration, but also to provide strategies and suggestions for foot pressure alleviation and pain mitigation.
... The data originate from a 10-year follow-up study of patients with diabetes requiring prescribed footwear [13]. The inclusion criteria for patients eligible to participate in the study were: being a patient in the original research, being referred to and prescribed footwear at the Department of Prosthetics & Orthotics (DPO) at Sahlgrenska University Hospital, having a diagnosis of diabetes mellitus, age ≥ 18 years, understanding the Swedish language and being able to ambulate without any walking aid. ...
... All the patients in the original study were randomised to use 1) custom-made 55 shore EVA insoles with a custom-made metatarsal pad, 2) custom-made 35 shore EVA insoles with a custom-made metatarsal pad or 3) prefabricated GloboTec® Comfort 312750501400 Bauerfeind insoles with a standard metatarsal pad. The prefabricated insoles were constructed with a rigid thermoplastic base and a top layer of 12-shore EVA [13]. ...
Patients with diabetes are often prescribed insoles with metatarsal pads intended to prevent and offload forefoot ulcers. However, to our knowledge, the plantar pressures specifically at the metatarsal pad had not previously been researched. The aim of this study was therefore to explore plantar pressures at the metatarsal pad position by comparing three toe deformity groups, claw toe (CT)/hammer toe (HT) and hallux valgus (HV), with a control group (NONE). In-shoe plantar pressures were measured using F-ScanTM and a polygon region of interest at the metatarsal pad position was created. Mean peak pressure (MPP), pressure-time integral (PTI) and percentage foot-insole contact area at the metatarsal pad position (%CA) were analysed from 24 patients (48 feet) in the metatarsal pad area. No significant difference was found between the groups regarding MPP, PTI or contact area. For MPP, the highest value was found in CT/HT (140kPa ± 61) and the lowest in HV (112kPa ± 33). In PTI, the highest value was for CT/HT (2.0 Ns/cm2 ± 1.0) and the lowest for HV (1.3 Ns/cm2 ± 0.4). The %CA was highest in CT/HT/HV (95%) and lowest in NONE (70%). A new quantitative approach was presented, assessing the metatarsal pad pressure effect on its corresponding plantar area of the foot. Further studies are needed to identify the conditions in which a metatarsal pad affects different foot statuses with regard to plantar pressure.
... However, some patients require a further reduction in peak plantar pressure either at the forefoot or hindfoot to prevent ulceration and to reduce the occurrence of pain. Experimental and FEA studies have highlighted the heel as one of the most frequently encountered regions with pain in all populations, including athletes and diabetic patients with a high risk of foot ulceration [41,42]. Metatarsal pads and small plugs are used to reduce the peak plantar pressure under metatarsal heads [37,43]. ...
To reduce the trial and error in a real clinical scenario, the finite element analysis (FEA) can be effectively used to simulate various effective pad designs and a material selection to reduce and redistribute peak plantar pressure in a diabetic foot with neuropathy. The aim of this study was to investigate the effect of pad design and material stiffness on the reduction in plantar pressure in a diabetic foot with neuropathy using FEA. Three-dimensional foot models with a customized insole (CMI) were created to study the peak contact pressure. Ethylene vinyl acetate, Nora® Lunalastike, and thermoplastic polyurethane were assigned to the top, middle, and base layers of the CMI, respectively. Two types of pads were proposed: a heel pad and a heel–forefoot pad. Four different materials with different stiffnesses were assigned as pad materials including a void pad. The FEA revealed that pads with soft materials reduced peak plantar pressure more effectively than stiffer pads. The use of a softer heel–forefoot pad reduced the peak plantar pressure at the midfoot and forefoot compared with other pads. The findings suggest that the material and design selection for the fabrication of CMIs with pads are important factors in reducing plantar pressure and may be useful in the management of a neuropathic diabetic foot.
... In diabetic patients, higher plantar pressure increases the risk of developing plantar ulcers, which increases the need for lower extremity amputation [5,6] .The possibility of infection exists if a skin ulcer has developed. Only one-third of foot ulcers fully heal [3] . ...
Background: As a result, peripheral neuropathy is frequently caused by diabetes (DM). Diabetic plantar foot pressure ulcers develop from the lack of protective pain sensibility as a result of recurrent shear and tear pressures. Relieving pressure on the foot's sole is necessary for the ulcers to heal. Objective: This study aimed to test the effectiveness of surgical and non-surgical unloading procedures in healing of plantar ulcers. Subjects and methods: 50 diabetic foot ulcer patients who visited Ain Shams University, The National Institute of DM, and the Endocrinology Outpatient Clinic participated in this interventional trial (NIDE). We employed mechanical and surgical unloading methods in this trial, and patients were monitored for 6 months to see how long it took for their injuries to recover. Results: At the conclusion of the follow-up period, 88% of the surgical group's pressure ulcers were fully healed compared to 86.7% of the non-surgical patients (6 months). Infection, recurrence, and non-healing were complications we encountered throughout the follow-up period. Regarding the treatment of plantar diabetic foot ulcers (DFUs), offloading is crucial. Compared to using only non-surgical methods, surgical offloading may hasten the recovery time. A well-trained team is necessary to prevent the issues with improperly fitting footwear and to teach the patient how to use them on a regular basis with the non-surgical offloading technique.
... Soft material with lower density of Nora Lunalastik EVA (hardness of 23 Shore A) performed better than the rigid material with higher density of Nora Lunalight A fresh (hardness of 58 Shore A) on offloading plantar pressure in this study. The result is in line with the finding of Tang et al. 56 , low density ethylene-vinyl acetate (i.e., Nora Lunalastik EVA) is generally soft and provides good cushioning, shock absorption during walk 30 . In general, the softness of insole material relates with better performance on plantar pressure offloading in this study. ...
Abstract To investigate the effect of contoured insoles constructed of different insole materials, including Nora Lunalastik EVA, Nora Lunalight A fresh, Pe-Lite, and PORON Medical 4708 with Langer Biomechanics longitudinal PPT arch pads on offloading plantar pressure on the foot of the elderly with Type 1 or 2 diabetes during gait. Twenty-two elderly with Type 1 or 2 diabetes participated in the study. Their plantar pressure was measured by using an insole measurement system, while the participants walked 10 m in their bare feet or used each experimental insole in random order. The plantar surface was divided into four specific regions including the toes, forefoot, midfoot, and rearfoot. The mean peak pressure (MPP) and pressure–time integral (PTI) of ten steps with or without wearing one of the four insoles were analyzed on the dominant foot and the four specific plantar regions. After completion of the activities, the participants scored each insole from 1 (the least comfortable) to 10 (the most comfortable). The analysis of variance (ANOVA) factor of the insoles had significant effects on the MPP (P
... 10 The footwear is engineered to offer proper arch support and reduce the magnitude of plantar pressure on the metatarsal heads and bony prominences, which may build excessive hyperkeratotic tissues that eventually ulcerate. 11,12 International Working Group of Diabetic Foot (IWGDF) 2 guidelines recommend that people with loss of protective sensation (LOPS) or peripheral artery disease (PAD) must take extra care when selecting, or being fitted with, footwear; this is most important when they also have foot deformities (IWGDF risk-2) or have a history of a previous ulcer/amputation . Recommendations for footwear fitting are focused on TF length, the width of the metatarsal heads, and enough height to allow room for all the toes and possible deformities. ...
To evaluate the ability of high-risk patients with diabetes in remission to select proper therapeutic footwear (TF) and validate a novel 3D foot scanner app for selecting the proper fitting TF. We conducted a randomized and controlled clinical trial enrolling 30 patients with a previously healed diabetic foot ulcer carried out in a specialized diabetic foot unit between November 2021 and June 2022. All patients were recommended to TF with extra depth volume and rocker sole. The control group could acquire the TF size and model according to aesthetic preferences, while the experimental group had to acquire a specific size and model according to the result of a novel mobile app 3D feet scan. TF was recommended to change when the ill-fitting reasons were found, excessive length or tightness or compromise with toes. The primary outcome measure was the requirement of TF change after prescription because of ill-fitting. A total of seven patients required TF change, one of them (6.7%) in the experimental group and six patients (40%) in the control group (p = .031, 95% CI [0.011-1.04]). Reasons for ill-fitting were as follows: four patients due to excessive length and three patients due to toe compromise. The relative risk reduction for the need to change the TF via the foot scan compared to the control group was 83%, and the number needed to treat was 20. High-risk patients with diabetes tend to select TF with inadequate fitting (length or capacity), and they should be guided hand to hand to acquire proper TF.
