We assessed the efficacy of customized foot orthotic therapy by comparing reulceration rates, minor amputation rates, and work and daily living activities before and after therapy. Peak plantar pressures and peak plantar impulses were compared with the patients not wearing and wearing their prescribed footwear.
One hundred seventeen patients with diabetes were prescribed therapeutic insoles and footwear based on the results of a detailed biomechanical study and were followed for 2 years. All of the patients had a history of foot ulcers, but none had undergone previous orthotic therapy.
Before treatment, the reulceration rate was 79% and the amputation rate was 54%. Two years after the start of orthotic therapy, the reulceration rate was 15% and the amputation rate was 6%. Orthotic therapy reduced peak plantar pressures in patients with reulcerations and in those without (P < .05), although a significant decrease in peak plantar impulses was achieved only in patients not experiencing reulceration. Sick leave was reduced from 100% to 26%.
Personalized orthotic therapy targeted at reducing plantar pressures by off-loading protects high-risk patients against reulceration. Treatment reduced the reulceration rate and peak plantar pressures, leading to patients’ return to work or other activities. (J Am Podiatr Med Assoc 103(4): 281-290, 2013)
Effect of Orthotic Therapy on Claw Toe Loading
Results of Significance Testing at Pressure Sensor Units
This study demonstrates the effect of orthotic therapy for toe deformity on toe and metatarsal head pressures using a new analysis method facilitated by an in-shoe pressure-measurement system’s ability to export detailed data. Plantar pressure–time integrals in 11 individuals (22 feet) with claw deformity of the lesser toes were measured with and without toe props. Differences in pressure–time integrals at every individual sensor unit were then calculated for the two conditions, and significance was tested using the paired t-test. Plantar surface charts with contours of equal significant pressure–time integral change showed significant reduction under 17 second toes (77%), 22 third toes (100%), 15 fourth toes (68%), 13 second metatarsal heads (59%), 16 third metatarsal heads (73%), and 16 fourth metatarsal heads (73%). All 22 feet showed increases under the prop in the area of the third toe sulcus. This innovative approach to plantar pressure analysis could improve access to data that show significant pressure–time integral changes and, therefore, could advance the clinical application of plantar pressure measurement. (J Am Podiatr Med Assoc 94(3): 246–254, 2004)
In a previous pilot study of “cruisers” (nonindependent ambulation), “early walkers” (independent ambulation for 0–5 months), and “experienced walkers” (independent ambulation for 6–12 months), developmental age significantly affected the children’s stability when walking and performing functional activities. We sought to examine how shoe structural characteristics affect plantar pressure distribution in early walkers.
Torsional flexibility was evaluated in four shoe designs (UltraFlex, MedFlex, LowFlex, and Stiff based on decreasing relative flexibility) with a structural testing machine. Plantar pressures were recorded in 25 early walkers while barefoot and shod at self-selected walking speeds. Peak pressure was calculated over ten masked regions for the barefoot and shod conditions.
Torsional flexibility, the angular rotation divided by the applied moment about the long axis of the shoe, was different across the four shoe designs. As expected, UltraFlex was the most flexible and Stiff was the least flexible. As applied moment increased, torsional flexibility decreased in all footwear. When evaluating early walkers during gait, peak pressure was significantly different across shoe conditions for all of the masked regions. The stiffest shoe had the lowest peak pressures and the most flexible shoe had the highest.
It is likely that increased shoe flexibility promoted greater plantar loading. Plantar pressures while wearing the most flexible shoe are similar to those while barefoot. This mechanical feedback may enhance proprioception, which is a desirable attribute for children learning to walk. (J Am Podiatr Med Assoc 103(4): 297–305, 2013)
One hundred eighty-seven type 2 diabetic patients without a history of foot ulceration were followed for a mean period of 3.6 years to investigate the incidence of foot ulceration in a diabetes cohort and to analyze risk factors for foot ulceration by multivariate means. During the study, 10 subjects developed 18 forefoot ulcerations. In multivariate logistic regression, significant predictors for foot ulceration were an elevated vibration perception threshold (VPT) (relative risk [RR] = 25.4), an increased plantar pressure (RR = 6.3), and daily alcohol intake (RR = 5.1). This is the first prospective study to demonstrate plantar pressure and daily alcohol intake as predictors of foot ulceration among patients without previous ulceration. Further, VPT could be confirmed as the strongest predictor for foot ulceration, and it was clearly demonstrated that the more pronounced severity of complications occurred among subjects with elevated VPT. (J Am Podiatr Med Assoc 91(7): 343-350, 2001)
Is TCC-EZ a Suitable Alternative to Gold Standard Total-Contact Casting?
A Plantar Pressure Analysis
The total-contact cast (TCC) is the gold standard for off-loading diabetic foot ulcers (DFUs) given its nonremovable nature. However, this modality remains underused in clinical settings due to the time and experience required for appropriate application. The TCC-EZ is an alternative off-loading modality marketed as being nonremovable and having faster and easier application. This study aims to investigate the potential of the TCC-EZ to reduce foot plantar pressures.
Twelve healthy participants (six males, six females) were fitted with a removable cast walker, TCC, TCC-EZ, and TCC-EZ with accompanying brace removed. These off-loading modalities were tested against a control. Pedar-X technology measured peak plantar pressures in each condition. Statistical analysis of four regions of the foot (rearfoot, midfoot, forefoot, and hallux) was conducted with Friedman and Wilcoxon signed rank tests. Significance was set at P < .05.
All of the off-loading conditions significantly reduced pressure compared with the control, except the TCC-EZ without the brace in the hallux region. There was no statistically significant difference between TCC-EZ and TCC peak pressure in any foot region. The TCC-EZ without the brace obtained significantly higher peak pressures than with the brace. The removable cast walker produced similar peak pressure reduction in the midfoot and forefoot but significantly higher peak pressures in the rearfoot and hallux.
The TCC-EZ is a viable alternative to the TCC. However, removal of the TCC-EZ brace results in minimal plantar pressure reduction, which might limit clinical applications of the TCC-EZ.
We investigated plantar loading asymmetry during gait in American Indians with and without diabetes and with diabetes and peripheral neuropathy.
A convenience sample of 96 American Indians with and without diabetes was divided into three groups: 20 with diabetes and peripheral neuropathy, 16 with diabetes without peripheral neuropathy, and 60 with no history of diabetes (control group). Plantar loading was measured during barefoot walking across a pressure platform. Five trials were collected per foot during level walking at a self-selected speed using the two-step method. Asymmetry in peak pressure-time integral and peak plantar pressure were calculated from ten plantar regions and compared among groups.
Significant pressure-time integral asymmetry occurred across the forefoot regions in American Indians with diabetes and peripheral neuropathy compared with the other two groups. Significant peak plantar pressure asymmetry occurred in the third metatarsal region in both groups with diabetes (with and without peripheral neuropathy) compared with the control group.
Overall, American Indians with diabetes seemed to show greater asymmetry in plantar loading variables across the forefoot region compared with those in the control group. Specifically, individuals with diabetes and peripheral neuropathy had the greatest amount of forefoot pressure-time integral asymmetry. Significant peak plantar pressure asymmetry occurred in the third metatarsal region of the forefoot in those with diabetes with and without peripheral neuropathy. Loading asymmetry may play a role in the development of foot ulcers in the forefoot region of American Indians with peripheral neuropathy and diabetes. (J Am Podiatr Med Assoc 103(2): 106–112, 2013)
Background: Toe deformities are common foot abnormalities in older adults, contributing to functional disability, loss of balance, falls, and pressure lesions. The aim of this study was to evaluate the effectiveness of the custom-made molded silicone toe prop in distributing apical and metatarsophalangeal joint peak plantar pressures and force-time integral in toe deformities, including hammertoes and claw toes, and to observe any difference in pressures between flexible and rigid toe deformities.
Methods: A prospective quasi-experimental pretest/posttest study was conducted including 20 “healthy” older adults with a hammer or claw toe at the second digit. Ten subjects presented with a flexible toe and 10 subjects presented with a rigid toe. A molded silicone toe prop was devised for each participant. Dynamic plantar pressure measurements were taken/recorded before applying the toe prop and after the toe prop was placed under the toe.
Results: Significant differences in mean peak plantar pressure and pressure-time integral were observed at the apex of the second toe in both the flexible and rigid toe deformity when using a molded silicone toe prop. At the metatarsophalangeal joint, pressures were significantly reduced in the rigid toe deformity but not in the flexible toe deformity.
Conclusions: Silicone molded toe props were found to be effective in reducing peak pressure and pressure-time integral on the apex of the second digit in participants with both flexible and rigid claw or hammertoe deformity. Lesser toe deformities may be the cause of several foot complications, including pain on walking, corns, difficulty in wearing footwear, possible ulcerations caused by increased pressure at the apices of the toes, and other comorbidities, that could possibly lead to falls in older adults and thus need to be addressed appropriately.
Background: Podiatric physicians are increasingly using pedobarographs to measure plantar pressure. However, normal values of static pedobarographic variables for healthy men and women are lacking, which makes it difficult to evaluate abnormal foot positioning in standing patients with low- or high-arched feet or painful feet.
Methods: During upright standing, a computerized pedobarograph measured the maximal (Pmax) and mean (Pmean) plantar pressures, total foot area, and forefoot and rearfoot areas in 84 healthy women and 84 healthy men, aged 18 to 83 years. After calibration of the pedobarograph, a correction factor was applied to area measurements, and data repeatability was assessed.
Results: The Pmax and Pmean values were not correlated with age but with weight, body mass index, and shoe size. Total foot area was significantly higher in male participants and correlated with body weight, body mass index, and shoe size but not with age. In both sexes, forefoot area was significantly lower than rearfoot area. Significant positive correlations were observed between forefoot and rearfoot areas and weight and shoe size. The forefoot-rearfoot area ratio did not vary with sex, weight, shoe size, and age.
Conclusions: These data provide relationships between Pmax, Pmean, and foot areas and weight and shoe size and clearly indicate no age dependence of pedobarographic data. They also provide stable values of the forefoot-rearfoot area ratio. These data should help clinicians evaluate abnormal foot placement in standing patients.
Accurate representation of the insole geometry is crucial for the development and performance evaluation of foot orthoses designed to redistribute plantar pressure, especially for diabetic patients.
Considering the limitations in the type of equipment and space available in clinical practices, this study adopted a simple portable three-dimensional (3-D) desktop scanner to evaluate the 3-D geometry of an orthotic insole and the corresponding deformities after the insole has been worn. The shape of the insole structure along horizontal cross sections is defined with 3-D scanning and image processing. Accompanied by an in-shoe pressure measurement system, plantar pressure distribution in four foot regions (hallux, metatarsal heads, midfoot, and heel) is analyzed and evaluated for insole deformity.
Insole deformities are quantified across the four foot regions. The hallux region tends to show the greatest changes in shape geometry (17%–50%) compared with the other foot regions after 2 months of insole wear. As a result of insole deformities, plantar peak pressures change considerably (–4.3% to +69.5%) during the course of treatment.
Changes in shape geometry of the insoles could be objectively quantified with 3-D scanning techniques and image processing. This investigation finds that, in general, the design of orthotic insoles may not be adequate for diabetic individuals with similar foot problems. The drastic changes in the insole shape geometry and cross-sectional areas during orthotic treatment may reduce insole fit and conformity. An inadequate insole design may also affect plantar pressure reduction. The approach proposed herein, therefore, allows for objective quantification of insole shape geometry, which results in effective and optimal orthotic treatment.
Pregnancy is a period when a woman's body undergoes changes. The purpose of this study was to analyze the mechanisms of gait adaptation in overweight pregnant women regarding spatiotemporal gait parameters, ground reaction forces, and plantar pressure distribution.
The tests were performed in 29 normal-weight pregnant women and 26 pregnant women who were overweight before pregnancy. The measurements included spatiotemporal gait parameters, in-shoe plantar pressure distribution, and ground reaction forces during gestation.
The results indicate that both normal-weight and overweight pregnant women make use of the same spatiotemporal gait parameters to increase body stability and safety of movement during pregnancy. The double-step duration in the third trimester of pregnancy was higher in normal-weight and overweight pregnant women compared with in the first trimester (P < .05). A significant change in pressure amplitude was found under all anatomical parts of the foot in the third trimester (P < .05). The results also suggest a higher increase in the maximum amplitude of force in overweight pregnant women in the third trimester compared with the normal-weight group.
This study suggests that both normal-weight and overweight pregnant women use different mechanisms of gait adaptation during pregnancy. In practice, understanding the biomechanical changes in women's gait can protect the musculoskeletal system during gestation.