In-shoe Plantar Pressure Research Articles

3P2-J05 歩行中に靴内でフットウェアが足底に与える圧力およびせん断力の評価(看護とメカトロニクス)

3P2-J05 歩行中に靴内でフットウェアが足底に与える圧力およびせん断力の評価(看護とメカトロニクス)

Is it possible to predict optimal rocker shoe design using barefoot gait parameters?

Curved rocker shoes are routinely prescribed for people with diabetes in order reduce in-shoe plantar pressures. However, previous research has shown that different individuals may require different rocker outsole geometries in order to optimise pressure reduction [1, 2]. This has led some researchers to suggest that every individual should try a range of possible outsole designs to identify the design which maximises pressure reduction [1]. However, this process may not be feasible in a clinical setting. Given that plantar pressure has been shown to depend on specific gait variables [3], it may be possible to develop an algorithm which could predict an individual’s pressure response to a specific rocker outsole design using an input of gait data. Such an algorithm would remove the need to try on a large number of pairs of rocker shoes.

Effect of rocker shoes on plantar pressure pattern in healthy female runners

Rocker profile shoes (rocker shoes) are one of the treatment options of metatarsalgia and forefoot stress fractures. The efficacy of rocker shoes in unloading the forefoot pressure has been shown in walking. In running, however, the effect of rocker shoes on forefoot pressure is unknown. Eighteen healthy female runners participated in this study. In-shoe plantar pressures were recorded during running with the standard running shoes and rocker shoes. Shoe comfort was assessed after each shoe measurement. Peak pressure (PP), maximum mean pressure (MMP) and force-time integral (FTI) were determined for seven foot areas. The effects of shoes on the different outcome variables were statistically analyzed using a linear mixed model. Running with the rocker shoes caused a significant reduction (p<0.001) in all pressure parameters in the central and lateral forefoot. FTI and MMP were also reduced by 11% and 12% in the medial forefoot while running with rocker shoes. Running with rocker shoes resulted in a significant increase in all pressure parameters at the heel region (p<0.001). Running with rocker shoes received a significant (p<0.01) lower comfort rate than running with standard running shoes. Rocker shoes might be beneficial for runners who are recovering from metatarsalgia or stress fractures of the forefoot region, as it reduces plantar pressure in the forefoot region.

A Gait Recognition System using GA-based C-SVC and Plantar Pressure

In order to conduct the gait recognition system, a wireless in-shoe wearable plantar pressure acquisition system based on ATmega16 and 8 FSR sensors was applied to data acquisition for the gaits which consist of standing, walking, jumping and going upstairs. And four volunteers (2 females and 2 males) were invited in this research to collect the pressure information. MATLAB and LIBSVM were applied to conduct all algorithms proposed by this study. Genetic Algorithm (GA) was used to set the best tuning (penalty) parameter and the best (gamma) of Gauss radial basis kernel (RBF) for C-support vector classification (C-SVC) model and the GA-based C-SVC was obtained. A dataset named ‘train-data’, containing 800 sets of pressure data was used to train the GA-based C-SVC as the algorithm of gait recognition. Finally a testing dataset containing 400 sets of pressure data was applied to test the algorithm of gait recognition called GA-based C-SVC. The accuracy of this GA-based C-SVC was 98% for standing, 91% for walking, 82% for going-upstairs and 97% for jumping. In generally speaking, a better GA-based C-SVC was obtained in this research. DOI: http://dx.doi.org/10.11591/telkomnika.v11i10.2962

Diabetic foot ulcer incidence in relation to plantar pressure magnitude and measurement location

AimsWe prospectively examined the relationship between site-specific peak plantar pressure (PPP) and ulcer risk. Researchers have previously reported associations between diabetic foot ulcer and elevated plantar foot pressure, but the effect of location-specific pressures has not been studied. MethodsDiabetic subjects (n=591) were enrolled from a single VA hospital. Five measurements of in-shoe plantar pressure were collected using F-Scan. Pressures were measured at 8 areas: heel, lateral midfoot, medial midfoot, first metatarsal, second through fourth metatarsal, fifth metatarsal, hallux, and other toes. The relationship between incident plantar foot ulcer and PPP or pressure–time integral (PTI) was assessed using Cox regression. ResultsDuring follow-up (2.4years), 47 subjects developed plantar ulcers (10 heel, 12 metatarsal, 19 hallux, 6 other). Overall mean PPP was higher for ulcer subjects (219 vs. 194kPa), but the relationship differed by site (the metatarsals with ulcers had higher pressure, while the opposite was true for the hallux and heel). A statistical analysis was not performed on the means, but hazard ratios from a Cox survival analysis were nonsignificant for PPP across all sites and when adjusted for location. However, when the metatarsals were considered separately, higher baseline PPP was significantly associated with greater ulcer risk; at other sites, this relationship was nonsignificant. Hazard ratios for all PTI data were nonsignificant. ConclusionsLocation must be considered when assessing the relationship between PPP and plantar ulceration.

Effects of shoe sole hardness on plantar pressure and comfort in older people with forefoot pain

Plantar forefoot pain is common in older people and is related to increased peak pressures under the foot during gait. Variations in the hardness of the shoe sole may therefore influence both the magnitude of loading under the foot and the perceived comfort of the shoe in this population. The aim of this investigation was to determine the effect of varying shoe sole hardness on plantar pressures and comfort in older people with forefoot pain. In-shoe plantar pressures under the forefoot, midfoot and rearfoot were recorded from 35 older people (mean age 73.2, SD 4.5 years) with current or previous forefoot pain using the pedar-X® system. Participants walked at their normal comfortable speed along an 8m walkway in shoes with three different levels of sole hardness: soft (Shore A25), medium (Shore A40) and hard (Shore A58). Shoe comfort was measured on a 100mm visual analogue scale. There were statistically significant differences in peak pressure of between 5% and 23% across the forefoot, midfoot and rearfoot (p<0.01). The hard-soled shoe registered the highest peak pressures and the soft-soled shoe the lowest peak pressures. However, no differences in comfort scores across the three shoe conditions were observed. These findings demonstrate that as shoe sole hardness increases, plantar pressure increases, however this does not appear to have a significant effect on shoe comfort.

Plantar Pressures, Plantar Forces, and Their Influence on the Pathogenesis of Diabetic Foot Ulcers

Clinical recommendations for the prevention and healing of diabetic foot ulcers (DFUs) are somewhat clear. However, assessment and quantification of the mechanical stress responsible for DFU remain complex. Different pressure variables have been described in the literature to better understand plantar tissue stress exposure. This article reviews the role of pressure and shear forces in the pathogenesis of plantar DFU. We performed systematic searches of the PubMed and Embase databases, completed by a manual search of the selected studies. From 535 potentially relevant references, 70 studies were included in the full-text review. Variables of plantar mechanical stress relate to vertical pressure, shear stress, and temporality of loading. At this time, in-shoe peak plantar pressure (PPP) is the only reliable variable that can be used to prevent DFU. Although it is a poor predictor of in-shoe PPP, barefoot PPP seems complementary and may be more suitable when evaluating patients with diabetes mellitus and peripheral neuropathy who seem noncompliant with footwear. An in-shoe PPP threshold value of 200 kPa has been suggested to prevent DFU. Other variables, such as peak pressure gradient and peak maximal subsurface shear stress and its depth, seem to be of additional utility. To better assess the at-risk foot and to prevent ulceration, the practitioner should integrate quantitative models of dynamic foot plantar pressures, such as in-shoe and barefoot PPPs, with the regular clinical screening examination. Prospective studies are needed to evaluate causality between other variables of mechanical stress and DFUs.

Effect of overground vs treadmill running on plantar pressure: Influence of fatigue

The differences produced when running on a treadmill vs overground may call into question the use and validity of the treadmill as a piece of equipment commonly used in research, training, and rehabilitation.The aim of the present study was to analyze under pre/post fatigue conditions the effect of treadmill vs overground on plantar pressures. Twenty-seven recreational runners (17 men and 10 women) ran on a treadmill and overground at two speeds: S1=3.33m/s and S2=4.00m/s, before and after a fatigue protocol consisting of a 30-min run at 85% of their individual maximal aerobic speed (MAS). Contact time (CT in seconds), peak pressure (PP in kPa), and relative load (RL in %) were analyzed under nine foot zones of the left foot using an in-shoe plantar pressure device.A two-way repeated measures ANOVA showed that running on a treadmill increases CT (7.70% S1 and 9.91% S2), modifies the pressure distribution and reduces PP (25.98% S1 and 31.76% S2), especially under the heel, medial metatarsals, and hallux, compared to running overground. Moreover, on both surfaces, fatigue (S2) led to a reduced stride frequency (2.78%) and reduced PP on the lateral heel and hallux (15.96% and 16.35%, respectively), and (S1) increased relative load on the medial arch (9.53%). There was no significant interaction between the two factors analyzed (surface and fatigue). Therefore, the aforementioned surface effect, which occurs independently of the fatigue state, should be taken into account when interpreting the results of studies that use the treadmill in their experimental protocols, and when prescribing physical exercise on a treadmill.

Pressure‐reduction and preservation in custom‐made footwear of patients with diabetes and a history of plantar ulceration

To assess the value of using in-shoe plantar pressure analysis to improve and preserve the offloading properties of custom-made footwear in patients with diabetes. Dynamic in-shoe plantar pressures were measured in new custom-made footwear of 117 patients with diabetes, neuropathy, and a healed plantar foot ulcer. In 85 of these patients, high peak pressure locations (peak pressure > 200 kPa) were targeted for pressure reduction (goal: > 25% relief or below an absolute level of 200 kPa) by modifying the footwear. After each of a maximum three rounds of modifications, pressures were measured. In a subgroup of 32 patients, pressures were measured and, if needed, footwear was modified at 3-monthly visits for 1 year. Pressures were compared with those measured in 32 control patients who had no footwear modifications based on pressure analysis. At the previous ulcer location and the highest and second highest pressure locations, peak pressures were significantly reduced by 23%, 21% and 15%, respectively, after modification of footwear. These lowered pressures were maintained or further reduced over time and were significantly lower, by 24-28%, compared with pressures in the control group. The offloading capacity of custom-made footwear for high-risk patients can be effectively improved and preserved using in-shoe plantar pressure analysis as guidance tool for footwear modification. This provides a useful approach to obtain better offloading footwear that may reduce the risk for pressure-related diabetic foot ulcers.

Offloading effect of therapeutic footwear in patients with diabetic neuropathy at high risk for plantar foot ulceration

Custom-made therapeutic footwear is often prescribed to patients with diabetic neuropathy, foot deformity and a healed plantar foot ulcer. Offloading these feet is important to prevent ulcer recurrence. The aim was to evaluate the offloading effect of custom-made footwear in these patients. In 171 patients with diabetic neuropathy (336 feet) with foot deformity and a recently healed plantar foot ulcer, plantar pressures walking barefoot and inside new custom-made footwear were measured. At the previous ulcer location and at locations of highest barefoot pressure attributable to the deformity, in-shoe pressures were compared with non-deformed feet. The footwear was considered effective in offloading when in-shoe peak pressure at these locations was < 200 kPa. Mean in-shoe peak pressures ranged between 211 and 308 kPa in feet with forefoot deformity (vs. 191-222 kPa in non-deformed feet) and between 140 and 187 kPa in feet with midfoot deformity (vs. 112 kPa in non-deformed feet). Offloading was effective in 61% of all feet with deformity, 81% of feet with midfoot deformity, 44% of feet with forefoot deformity and 62% of previous ulcer locations. Inter-subject variability in measured in-shoe plantar pressure was large. Offloading in custom-made footwear is often not sufficiently achieved in high-risk diabetic feet with deformity. Highest offloading success rates were seen at known high-risk locations such as previous ulcer locations and Charcot feet, the lowest success rates in forefoot deformities. Together with the large inter-subject variability in pressure outcomes, this emphasizes the need for evidence-based prescription and evaluation procedures to assure adequate offloading.

PS6 - 31. The effect of therapeutic footwear modifications on in-shoe plantar pressures in high risk diabetic patients

Custom-made therapeutic footwear is a common treatment used to prevent ulcer recurrence in diabetic patients with neuropathy.

PS6 - 34. The effectiveness of offloading-improved custom-made footwear on plantar foot ulcer recurrence rate in diabetic patients: a multicenter randomized controlled trial

The aim of this study was to assess the effectiveness of custom-made footwear, of which offloading is improved based on in-shoe plantar pressure analysis, in preventing plantar foot ulcer recurrence in high-risk diabetic patients.

The effect of prefabricated and proprioceptive foot orthoses on plantar pressure distribution in patients with flexible flatfoot during walking

Previous studies have suggested that orthoses with different constructions could alter gait parameters in flexible flatfoot. However, there is less evidence about the effect of insoles with proprioceptive mechanism on plantar pressure distribution in flatfoot. To assess the effect of orthoses with different mechanisms on plantar pressure distribution in subjects with flexible flatfoot. Quasi-experimental. In total, 12 flatfoot subjects were recruited for this study. In-shoe plantar pressure in walking was measured by Pedar-X system under three conditions including wearing the shoe only, wearing the shoe with a proprioceptive insole, and wearing the shoe with a prefabricated foot insole. Using the proprioceptive insoles, maximum force was significantly reduced in medial midfoot, and plantar pressure was significantly increased in the second and third rays (0.94 ± 0.77 N/kg, 102.04 ± 28.23 kPa) compared to the shoe only condition (1.12 ± 0.88 N/kg and 109.79 ± 29.75 kPa). For the prefabricated insole, maximum force was significantly higher in midfoot area compared to the other conditions (p < 0.05). Construction of orthoses could have an effect on plantar pressure distribution in flatfeet. It might be considered that insoles with sensory stimulation alters sensory feedback of plantar surface of foot and may lead to change in plantar pressure in the flexible flatfoot. Based on the findings of this study, using orthoses with different mechanisms such as proprioceptive intervention might be a useful method in orthotic treatment. Assessing plantar pressure can also be an efficient quantitative outcome measure for clinicians in evidence-based foot orthosis prescription.

Attenuation of foot pressure during running on four different surfaces: asphalt, concrete, rubber, and natural grass

The practice of running has consistently increased worldwide, and with it, related lower limb injuries. The type of running surface has been associated with running injury etiology, in addition other factors, such as the relationship between the amount and intensity of training. There is still controversy in the literature regarding the biomechanical effects of different types of running surfaces on foot–floor interaction. The aim of this study was to investigate the influence of running on asphalt, concrete, natural grass, and rubber on in-shoe pressure patterns in adult recreational runners. Forty-seven adult recreational runners ran twice for 40 m on all four different surfaces at 12 ± 5% km · h−1. Peak pressure, pressure-time integral, and contact time were recorded by Pedar X insoles. Asphalt and concrete were similar for all plantar variables and pressure zones. Running on grass produced peak pressures 9.3% to 16.6% lower (P < 0.001) than the other surfaces in the rearfoot and 4.7% to 12.3% (P < 0.05) lower in the forefoot. The contact time on rubber was greater than on concrete for the rearfoot and midfoot. The behaviour of rubber was similar to that obtained for the rigid surfaces – concrete and asphalt – possibly because of its time of usage (five years). Running on natural grass attenuates in-shoe plantar pressures in recreational runners. If a runner controls the amount and intensity of practice, running on grass may reduce the total stress on the musculoskeletal system compared with the total musculoskeletal stress when running on more rigid surfaces, such as asphalt and concrete.

INCREASED STRENGTH OF INTRINSIC FOOT MUSCLES IN DIABETES AND PERIPHERAL NEUROPATHY

Running is one of the most accessible physical activities and running with and without footwear has attracted extensive attention in the past several years. In this study 18 habitually male unshod runners and 20 habitually male shod runners (all with dominant right feet) participated in a running test. A Vicon motion analysis system was used to capture the kinematics of each participant’s lower limb. The in-shoe plantar pressure measurement system was employed to measure the pressure and force exerted on the pressure sensors of the insole. The function of a separate hallux in unshod runners is analyzed through the comparison of plantar pressure parameters. Owing to the different strike patterns in shod and unshod runners, peak dorsiflexion and plantarflexion angle were significantly different. Habitually shod runners exhibited a decreased foot strike angle (FSA) under unshod conditions; and the vertical average loading rate (VALR) of shod runners under unshod conditions was larger than that under shod conditions. This suggests that the foot strike pattern is more important than the shod or unshod running style and runners need to acquire the technique. It can be concluded that for habitually unshod runners the separate hallux takes part of the foot loading and reduces loading to the forefoot under shod conditions. The remaining toes of rearfoot strike (RFS) runners function similarly under unshod conditions. These morphological features of shod and unshod runners should be considered in footwear design to improve sport performance and reduce injury.

Effect of selected exercises on in-shoe plantar pressures in people with diabetes and peripheral neuropathy

BackgroundIn people with diabetes and peripheral neuropathy (DM+PN), injury risk is not clearly known for weight bearing (WB) vs. non-weight bearing (NWB) exercise. In-shoe peak plantar pressures (PPP) often are used as a surrogate indicator of injury to the insensitive foot. ObjectiveCompare PPPs in people with DM+PN during selected WB and NWB exercises. MethodsFifteen subjects with DM+PN participated. PPPs were recorded for the forefoot, midfoot, and heel during level walking and compared to; WB exercises – treadmill walking, heel and toe raises, sit to stands, stair climbing, single leg standing; and NWB exercises – stationary bicycling, balance ball exercise and plantar flexion exercise. ResultsCompared to level walking; mean forefoot PPP during treadmill walking was 13% higher, but this difference was eliminated when walking speed was used as a covariate. Mean PPPs were similar or substantially lower for other exercises, except for higher forefoot PPP with heel raise exercises. ConclusionsSlow progression and regular monitoring of insensitive feet are recommended for all exercises, but especially for heel raises, and increases in walking speed. The remaining WB and NWB exercises pose no greater risk to the insensitive foot due to increases in PPP compared to level walking.

The effects of standard issue Royal Marine recruit footwear on risk factors associated with third metatarsal stress fractures

Purpose: The relatively high incidence rate of third metatarsal (MT3) stress fractures in Royal Marine (RM) recruits may be linked to the footwear worn during training. The present study investigated the effect of standard issue RM recruit footwear on biomechanical variables linked with MT3 stress fracture risk. Methods: Seven male volunteers (age 18.3 ± 0.4 years, mass 81.1 ± 8.2 kg) ran at 3.6 m s−1 in a laboratory while wearing a combat assault boot (CAB) and a neutral gym trainer (GT). In-shoe plantar pressure was assessed using pressure insoles (RSScan, 500 Hz). Two-dimensional ankle kinematics and kinetics were assessed at 120 Hz (Peak Motus). Horizontal ground reaction force characteristics were investigated using an AMTI force plate (960 Hz). Results: Peak plantar pressure, impulse and loading rate were significantly greater at the MT3 head in the CAB (P < 0.05). Further significant differences with the CAB were a smaller and earlier peak ankle dorsiflexion, a later heel-off, and greater magnitudes of peak plantarflexion moment and ankle joint stiffness (P < 0.05). At the instant of peak horizontal braking force, the resultant horizontal force vector was applied significantly more laterally in the CAB than the GT. Conclusions: The higher magnitude for several risk factors for MT3 stress fracture when wearing the CAB compared with the GT suggests that wearing the CAB contributes to the high incidence of MT3 stress fracture in RM recruits. Increased ankle stiffness was attributed to above-ankle support and increased eccentric muscular control in the CAB, contributing to the higher plantar loading at the MT3 head. The higher plantarflexion moment and associated increased muscular demand in the CAB may have implications for fatigue-related MT3 stress fracture mechanisms, although further research is required to support this.

The effectiveness of using in‐shoe plantar pressure assessment and monitoring in prescription therapeutic footwear to prevent plantar foot ulcer recurrence in diabetic patients: a multicenter randomized controlled trial

Background Diabetic patients at high risk for foot ulceration are often prescribed with custom-made therapeutic footwear. However, the evidence base to support the use of this footwear for ulcer prevention is still meagre [1]. The lack of offloading efficacy may play a role in this. In-shoe plantar pressure assessment is a valuable tool for evaluating footwear and guiding modifications to optimize the footwear’s offloading properties [2]. The aim of this multicenter randomized trial was to assess the effectiveness of this approach and long-term pressure monitoring in prescription footwear to prevent plantar foot ulcer recurrence in neuropathic diabetic patients.

Methodology for Use of a Neuroprosthetic to Reduce Plantar Pressure: Applications in Patients with Diabetic Foot Disease

Methodology for Use of a Neuroprosthetic to Reduce Plantar Pressure: Applications in Patients with Diabetic Foot Disease

Comparison of plantar pressure distribution in adolescent runners at low vs. high running velocity

This study aimed to compare foot plantar pressure distribution while jogging and running in highly trained adolescent runners. Eleven participants performed two constant-velocity running trials either at jogging (11.2±0.9km/h) or running (17.8±1.4km/h) pace on a treadmill. Contact area (CA in cm2), maximum force (Fmax in N), peak pressure (PP in kPa), contact time (CT in ms), and relative load (force time integral in each individual region divided by the force time integral for the total plantar foot surface, in %) were measured in nine regions of the right foot using an in-shoe plantar pressure device. Under the whole foot, CA, Fmax and PP were lower in jogging than in running (−1.2% [p<0.05], −12.3% [p<0.001] and −15.1% [p<0.01] respectively) whereas CT was higher (+20.1%; p<0.001). Interestingly, we found an increase in relative load under the medial and central forefoot regions while jogging (+6.7% and +3.7%, respectively; [p<0.05]), while the relative load under the lesser toes (−8.4%; p<0.05) was reduced. In order to prevent overloading of the metatarsals in adolescent runners, excessive mileage at jogging pace should be avoided.