Measurement of Dynamic Pressures at the Shoe-Foot Interface During Normal Walking with Various Foot Orthoses Using the FSCAN System

1996 ◽  
Vol 17 (3) ◽  
pp. 152-156 ◽  
Author(s):  
Melanie Brown ◽  
Sally Rudicel ◽  
Alberto Esquenazi
Keyword(s):  
Peak Pressure ◽  
Scientific Evidence ◽  
Foot Orthoses ◽  
Normal Walking ◽  
Plantar Surface ◽  
Confounding Variables ◽  
Stance Time ◽  
The Cost ◽  
Foot Orthosis ◽  
Do So

Foot orthoses are routinely used in clinical practice to redistribute pressure at the shoe-foot interface, although there is very little scientific evidence to support the efficacy of their use. In this study, the FSCAN sensor (an ultrathin in-shoe transducer) was used to determine the efficacy of pressure redistribution with a Plastizote, Spenco, cork, and a plastic foot orthosis as compared with control (no orthosis). Measurement variations of up to 18% occurred between sensors, and changes in stance time of up to 5% occurred between the orthoses and the control conditions. In spite of these potentially confounding variables, statistically significant differences in peak pressure between the orthotic types and the control condition (range, 9–146%) were noted. We conclude that Plastizote, cork, and plastic foot orthoses can be beneficial in relieving pressure in certain regions of the shoe-foot interface, but that they may do so at the cost of increasing pressure in other areas of the plantar surface.

Changes in Plantar Foot Pressure with In-Shoe Varus or Valgus Wedging

2004 ◽  
Vol 94 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Bart Van Gheluwe ◽  
Howard J. Dananberg
Keyword(s):  
Pressure Distribution ◽  
Loading Rate ◽  
Peak Pressure ◽  
Center Of Pressure ◽  
Scientific Evidence ◽  
Peak Load ◽  
Foot Orthoses ◽  
Foot Pressure ◽  
Custom Made

Varus and valgus wedging are commonly used by podiatric physicians in therapy with custom-made foot orthoses. This study aimed to provide scientific evidence of the effects on plantar foot pressure of applying in-shoe forefoot or rearfoot wedging. The plantar foot pressure distribution of 23 subjects walking on a treadmill was recorded using a pressure insole system for seven different wedging conditions, ranging from 3° valgus to 6° varus for the forefoot and from 4° valgus to 8° varus for the rearfoot. The results demonstrate that increasing varus wedging magnifies peak pressure and maximal loading rate at the medial forefoot and rearfoot, whereas increasing valgus wedging magnifies peak pressure and maximal loading rate at the lateral forefoot and rearfoot. As expected, the location of the center of pressure shifts medially with varus wedging and laterally with valgus wedging. However, these shifts are less significant than those in peak load and maximal loading rate. Timing variables such as interval from initial impact to peak load do not seem to be affected by forefoot or rearfoot wedging. Finally, rearfoot wedging does not significantly influence pressure variables of the forefoot; similarly, rearfoot pressure remains unaffected by forefoot wedging. (J Am Podiatr Med Assoc 94(1): 1-11, 2004)

Effect of medial arch support foot orthosis on plantar pressure distribution in females with mild-to-moderate hallux valgus after one month of follow-up

2014 ◽  
Vol 39 (2) ◽  
pp. 134-139 ◽  
Author(s):  
Maede Farzadi ◽  
Zahra Safaeepour ◽  
Mohammad E Mousavi ◽  
Hassan Saeedi
Keyword(s):  
Pressure Distribution ◽  
Hallux Valgus ◽  
Plantar Pressure ◽  
Peak Pressure ◽  
Foot Orthoses ◽  
First Metatarsal ◽  
Plantar Pressure Distribution ◽  
Before And After ◽  
Arch Support ◽  
Foot Orthosis

Background:Higher plantar pressures at the medial forefoot are reported in hallux valgus. Foot orthoses with medial arch support are considered as an intervention in this pathology. However, little is known about the effect of foot orthoses on plantar pressure distribution in hallux valgus.Objectives:To investigate the effect of a foot orthosis with medial arch support on pressure distribution in females with mild-to-moderate hallux valgus.Study design:Quasi-experimental.Methods:Sixteen female volunteers with mild-to-moderate hallux valgus participated in this study and used a medial arch support foot orthosis for 4 weeks. Plantar pressure for each participant was assessed using the Pedar-X®in-shoe system in four conditions including shoe-only and foot orthosis before and after the intervention.Results:The use of the foot orthosis for 1 month led to a decrease in peak pressure and maximum force under the hallux, first metatarsal, and metatarsals 3–5 ( p < 0.05). In the medial midfoot region, peak pressure, maximum force, and contact area were significantly higher with the foot orthosis than shoe-only before and after the intervention ( p = 0.00).Conclusion:A foot orthosis with medial arch support could reduce pressure beneath the hallux and the first metatarsal head by transferring the load to the other regions. It would appear that this type of foot orthosis can be an effective method of intervention in this pathology.Clinical relevanceFindings of this study will improve the clinical knowledge about the effect of the medial arch support foot orthosis used on plantar pressure distribution in hallux valgus pathology.

scholarly journals Comparison of plantar pressure distribution patterns between foot orthoses provided by the CAD-CAM and foam impression methods

2008 ◽  
Vol 32 (3) ◽  
pp. 356-362 ◽  
Author(s):  
S. W. Ki ◽  
A. K. L. Leung ◽  
A. N. M. Li
Keyword(s):  
Plantar Pressure ◽  
Peak Pressure ◽  
Weight Bearing ◽  
Measuring System ◽  
Maximum Force ◽  
Foot Orthoses ◽  
Computer Aided ◽  
Cad Cam ◽  
Partial Weight ◽  
Foot Orthosis

Foot orthotic treatment is one of the major conservative methods used to handle foot problems. Total plantar contact foot orthoses are used to reduce and redistribute peak pressures. For the fabrication of a total plantar contact foot orthosis, the computer-aided design and computer-aided manufacturing (CAD-CAM) method has been applied. In this study, the plantar foot-orthosis interface pressure data during walking were collected by the Novel Pedar-mobile in-shoe plantar pressure measuring system. The data were collected under three conditions: (i) Flat insole, (ii) foot orthosis provided by the CAD-CAM method, and (iii) foot orthosis provided by the foam impression method. The Swiss Comfort CAD-CAM foot orthotics system was used in this study. For conditions (ii) and (iii), foot shapes were collected in partial weight bearing and subtalar neutral conditions. Thirty normal subjects were recruited for this study. The plantar foot surface was divided into eight plantar foot regions and then was investigated. These regions included the heel, the medial and lateral arches, the medial, mid and lateral forefoot, the hallux, and the lateral toes. The results showed that the orthoses provided by both the CAD-CAM and foam impression methods could decrease the peak pressure and the maximum force in the heel region, and increase the peak pressure and the maximum force in the medial arch region. Both orthoses redistributed the peak pressure and the maximum force from the heel to the medial arch region. The peak pressure in the mid forefoot region was different between the orthoses provided by the CAD-CAM and foam impression methods.

scholarly journals An Improved Smart Ankle Foot Othosis Design Using Dual Fluid Power Cylinders

2010 ◽  
Vol 4 (2) ◽  
Author(s):  
Ricky Mehta ◽  
Eric L. Rohrs ◽  
Katarina F. Lipat ◽  
Evan C. Reed ◽  
Manish Paliwal
Keyword(s):  
Hydraulic Cylinder ◽  
Metatarsal Head ◽  
Foot Drop ◽  
Heel Strike ◽  
Neutral Position ◽  
Foot Orthoses ◽  
Ankle Foot Orthosis ◽  
Plantar Surface ◽  
Ankle Foot Orthoses ◽  
Foot Orthosis

To design a smart ankle-foot orthosis (SAFO) that improves upon current ankle-foot orthoses used to treat steppage gait. Current ankle-foot orthoses are subjected to significant stresses on the ankle region of the structure, causing discomfort and the possible failure of the AFO. Although these AFOs have a constant stiffness, they do not reduce the occurrence of slap foot, where the foot slaps on the ground rather than gradually lowering it. The SAFO is an active ankle-foot orthosis that allows the user’s foot to follow a normal gait cycle. It is designed to reduce stress at the ankle by allowing for movement of the foot beyond a 90 deg angle for plantarflexion. The hinged ankle-foot orthosis is incorporated with a novel dual hydraulic-cylinder system, two tension springs, and force sensitive resistors. The force sensors are placed at the hallux, first metatarsal head, fifth metatarsal base, and heel. The foot movement actuation follows the force applied to the plantar surface of the foot during gait. The sensor outputs are fed to a signal processor and control interface to coordinate the motor actuation with the forces exerted by the user. The motor turns the screw attached to the hydraulic cylinders, which, thereby, control the orifice size by moving a plate in the cylinder, thus, changing the resistance. The cylinder filled with air will be pressurized during the lean phase, as the orifices will be closed and will provide power just as a spring would during the heel-off phase. After the heel strike, the resistance of the fluid-filled cylinder is decreased to slowly lower the foot. Once the foot is flat, the resistance of the fluid-filled cylinder is increased to keep the foot in a position to allow for toe clearance. During the heel-off event, the air-filled cylinder will assist the user with the power to push off. When toe-off occurs, the fluid-filled cylinder will decrease the resistance to allow the tension springs to bring the foot back to neutral position. To power the motor and sensors, a rechargeable battery pack is placed in a waist bag. The SAFO’s flexible design uses a novel combination of hydraulic-pneumatic cylinders to prevent foot drop, and restore the user’s sense of normalcy by providing late stance plantarflexion and a return to neutral position in early swing phase.

scholarly journals Energy cost and muscular activity required for propulsion during walking

2003 ◽  
Vol 94 (5) ◽  
pp. 1766-1772 ◽  
Author(s):  
Jinger S. Gottschall ◽  
Rodger Kram
Keyword(s):  
Body Weight ◽  
Muscular Activity ◽  
Metabolic Cost ◽  
Medial Gastrocnemius ◽  
Emg Activity ◽  
Horizontal Force ◽  
Normal Walking ◽  
The Mean ◽  
The Cost ◽  
Muscle Actions

We reasoned that with an optimal aiding horizontal force, the reduction in metabolic rate would reflect the cost of generating propulsive forces during normal walking. Furthermore, the reductions in ankle extensor electromyographic (EMG) activity would indicate the propulsive muscle actions. We applied horizontal forces at the waist, ranging from 15% body weight aiding to 15% body weight impeding, while subjects walked at 1.25 m/s. With an aiding horizontal force of 10% body weight, 1) the net metabolic cost of walking decreased to a minimum of 53% of normal walking, 2) the mean EMG of the medial gastrocnemius (MG) during the propulsive phase decreased to 59% of the normal walking magnitude, and yet 3) the mean EMG of the soleus (Sol) did not decrease significantly. Our data indicate that generating horizontal propulsive forces constitutes nearly half of the metabolic cost of normal walking. Additionally, it appears that the MG plays an important role in forward propulsion, whereas the Sol does not.

Labor Migration and Climate Change Adaptation

2021 ◽  
pp. 1-13
Author(s):  
JAMIE DRAPER
Keyword(s):  
Climate Change ◽  
Labor Migration ◽  
Climate Adaptation ◽  
Scientific Evidence ◽  
Migration Policy ◽  
Labor Migrants ◽  
Acceptable Alternative ◽  
Social Scientific ◽  
The Normative Question ◽  
Do So

Social scientific evidence suggests that labor migration can increase resilience to climate change. For that reason, some have recently advocated using labor migration policy as a tool for climate adaptation. This paper engages with the normative question of whether, and under what conditions, states may permissibly use labor migration policy as a tool for climate adaptation. I argue that states may use labor migration policy as a tool for climate adaptation and may even have a duty to do so, subject to two moral constraints. First, states must also provide acceptable alternative options for adaptation so that the vulnerable are not forced to sacrifice their morally important interests in being able to remain where they are. Second, states may not impose restrictive terms on labor migrants to make accepting greater numbers less costly for themselves because doing so unfairly shifts the costs of adaptation onto the most vulnerable.

Comparison of the effect of foot orthoses on Star Excursion Balance Test performance in patients with chronic ankle instability

2018 ◽  
Vol 43 (1) ◽  
pp. 6-11 ◽  
Author(s):  
Faezeh Abbasi ◽  
Mahmood bahramizadeh ◽  
Mohammad Hadadi
Keyword(s):  
Ankle Sprain ◽  
Ankle Instability ◽  
Dynamic Balance ◽  
Chronic Ankle Instability ◽  
Textured Surface ◽  
Foot Orthoses ◽  
Textured Surfaces ◽  
Balance Test ◽  
Star Excursion Balance Test ◽  
Foot Orthosis

Background: Chronic ankle instability as a prevalent consequence of ankle sprain causes various impairments such as balance and postural control deficits. Foot orthoses are one of the common interventions for rehabilitation of patients with chronic ankle instability. Objectives: To investigate the effect of custom-molded foot orthoses with textured surfaces on dynamic balance of chronic ankle instability patients and to compare their effects with other types of foot orthoses. Study design: This is a repeated measure design. Methods: A total of 30 participants were recruited based on the guideline introduced by the International Ankle Consortium. The effect of prefabricated, custom-molded, and custom-molded with textured surface foot orthoses was evaluated on dynamic balance by the Star Excursion Balance Test. Normalized reach distances in anteromedial, medial, and posteromedial directions of the test were computed to be used for statistical analysis. Results: The foot orthoses increased reach distances compared to the no-orthosis conditions in all three directions. The custom-molded with textured surface foot orthosis has significant differences compared with prefabricated foot orthosis ( p = 0.001) in all measured directions and with custom-molded foot orthosis ( p < 0.01) in medial and posteromedial directions. Conclusion: Foot orthoses improve reach distances in patients with chronic ankle instability. Custom-molded with textured surface foot orthosis has a more pronounced effect compared with other foot orthoses. Clinical relevance The custom-molded foot orthosis with textured surface could be an effective device to improve dynamic balance in chronic ankle instability (CAI) patients. It may be considered as an efficient intervention to reduce ankle sprain recurrence in these individuals, although further research should be conducted.

The Effects of Talus Control Foot Orthoses in Children with Flexible Flatfoot

2017 ◽  
Vol 107 (1) ◽  
pp. 46-53 ◽  
Author(s):  
So Young Ahn ◽  
Soo Kyung Bok ◽  
Bong Ok Kim ◽  
In Sik Park
Keyword(s):  
Therapeutic Effect ◽  
Foot Orthoses ◽  
Talonavicular Joint ◽  
Radiographic Measurements ◽  
Flexible Flatfoot ◽  
Foot Orthosis

Background: A talus control foot orthosis (TCFO) combines an inverted rigid foot orthosis (RFO) with a broad upright portion that rises well above the navicular to cover and protect the talonavicular joint. We sought to identify the therapeutic effect of TCFOs in children with flexible flatfoot. Methods: Flexible flatfoot was diagnosed in 40 children when either of the feet had greater than 4° valgus of resting calcaneal stance position (RCSP) angle and one of the radiographic indicators was greater than 30° in anteroposterior talocalcaneal angles, 45° in lateral talocalcaneal angles, and 4° in lateral talometatarsal angles and less than 10° of calcaneal pitch in barefoot radiographs. Of 40 children with flexible flatfoot, 20 were fitted with a pair of RFOs and 20 with TCFOs, randomly. Follow-up clinical and radiographic measurements were completed 12 months later. Results: All of the radiographic indicators changed toward the corrective direction in both groups. There were significant improvements in calcaneal pitch and RCSP in both groups (P &lt; .05). In the TCFO group, the anteroposterior talocalcaneal angle and the RCSP showed statistically significant improvement compared with the RFO group. Conclusions: In this study, the TCFO was more effective than the RFO at treating children with flexible flatfoot.

scholarly journals A Three-Dimensional Printed Foot Orthosis for Flexible Flatfoot: An Exploratory Biomechanical Study on Arch Support Reinforcement and Undercut

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5297
Author(s):  
Ka-Wing Cheng ◽  
Yinghu Peng ◽  
Tony Lin-Wei Chen ◽  
Guoxin Zhang ◽  
James Chung-Wai Cheung ◽  
...  
Keyword(s):  
Peak Pressure ◽  
Reaction Force ◽  
Three Dimensional ◽  
Biomechanical Study ◽  
Rank Test ◽  
Arch Height ◽  
Vertical Ground Reaction Force ◽  
Flexible Flatfoot ◽  
Arch Support ◽  
Foot Orthosis

The advancement of 3D printing and scanning technology enables the digitalization and customization of foot orthosis with better accuracy. However, customized insoles require rectification to direct control and/or correct foot deformity, particularly flatfoot. In this exploratory study, we aimed at two design rectification features (arch stiffness and arch height) using three sets of customized 3D-printed arch support insoles (R+U+, R+U−, and R−U+). The arch support stiffness could be with or without reinforcement (R+/−) and the arch height may or may not have an additional elevation, undercutting (U+/−), which were compared to the control (no insole). Ten collegiate participants (four males and six females) with flexible flatfoot were recruited for gait analysis on foot kinematics, vertical ground reaction force, and plantar pressure parameters. A randomized crossover trial was conducted on the four conditions and analyzed using the Friedman test with pairwise Wilcoxon signed-rank test. Compared to the control, there were significant increases in peak ankle dorsiflexion and peak pressure at the medial midfoot region, accompanied by a significant reduction in peak pressure at the hindfoot region for the insole conditions. In addition, the insoles tended to control hindfoot eversion and forefoot abduction though the effects were not significant. An insole with stronger support features (R+U+) did not necessarily produce more favorable outcomes, probably due to over-cutting or impingement. The outcome of this study provides additional data to assist the design rectification process. Future studies should consider a larger sample size with stratified flatfoot features and covariating ankle flexibility while incorporating more design features, particularly medial insole postings.

Effect of 4 Weeks of Foot Orthosis Intervention on Ambulatory Capacities and Posture in Normal-Weight and Obese Patients

2020 ◽  
Vol 110 (1) ◽  
Author(s):  
Patricia Griffon ◽  
Bruno Vie ◽  
Jean Paul Weber ◽  
Yves Jammes
Keyword(s):  
Postural Sway ◽  
Center Of Pressure ◽  
Effective Means ◽  
Normal Weight ◽  
Foot Orthoses ◽  
Obese Patients ◽  
Healthy Individuals ◽  
Foot Arch ◽  
Foot Orthosis ◽  
Study Inclusion

Background: Several works have shown the benefits of foot orthosis intervention on postural stability in healthy individuals and patients with foot malalignment. However, the effects of foot orthoses on the daily ambulatory activities explored by the Six-Minute Walk Test (6MWT) were never examined. We hypothesized that foot orthoses could increase the gait distance and attenuate the post-6MWT posture alterations already reported in healthy individuals. Methods: In ten normal-weight (NW) and ten obese patients with foot malalignment and/or abnormal foot arch, we examined the benefits of 4 weeks of custom-molded orthosis intervention (D30) on 6MWT gait distance, fatigue sensation scores, ankle plantarflexion force, and post-6MWT sway of the center of pressure (COP) measured by a pedobarographic platform. Data were compared with those measured in two control-matched groups of ten NW and ten obese individuals, explored at study inclusion and at D30. Results: At study inclusion, the post-6MWT changes in COP surface and the medial and lateral COP deviations were significantly higher in obese participants who needed to wear the foot orthoses compared with obese control subjects. The foot orthosis intervention significantly improved the ambulatory performances of NW and obese individuals during the 6MWT, attenuated the bodily fatigue sensation after the 6MWT, and reduced the post-6MWT COP deviations, with the benefits of insoles being significantly accentuated in obese participants. Conclusions: Four weeks of foot orthosis intervention significantly increases gait distance and is an effective means to reduce postural sway after walking.

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