The intention of this investigation was to longitudinally describe and compare the plantar pressure distribution in orthostatic posture and gait throughout pregnancy.
A prospective longitudinal observational study was conducted with six pregnant women (mean ± SD age, 32 ± 3 years) with a mean ± SD weight gain of 10.0 ± 1.4 kg. Peak pressure, contact time, contact area, and maximum force in five plantar areas were evaluated using capacitive insoles during gait and orthostatic posture. For 1 year, the plantar pressures of pregnant women were evaluated the last month of each trimester. Comparisons among plantar areas and trimesters were made by analysis of variance.
For orthostatic posture, no differences in contact time, contact area, peak pressure, and maximum force throughout the trimesters were found. During gait, peak pressure and maximum force of the medial rearfoot were reduced from the first to third and second to third trimesters. Maximum force increased at the medial forefoot from the first to second trimester. Contact area increased at the lateral rearfoot from the second to third trimester and at the midfoot from the first to third trimester. Contact time increased at the midfoot and medial and lateral forefoot from the first to third trimester.
Pregnant women do not alter plantar pressure during orthostatic posture, but, during gait, the plantar loads were redistributed from the rearfoot (decrease) to the midfoot and forefoot (increase) throughout pregnancy. These adjustments help maintain the dynamic stability of the pregnant woman during locomotion. (J Am Podiatr Med Assoc 101(5): 415–423, 2011)
Plantar pressure plate instruments are commonly used in clinical practice and biomechanical analysis and are useful to establish a relationship between gait disorders and foot pressure. The aim of this study was to verify the reliability and repeatability of the Footwork pressure plate system for static and dynamic conditions.
Forty healthy adults, without apparent gait pathology, were recruited. For the static condition, participants were asked to stand static on the Footwork pressure plate for 5 sec in natural position (arms on either side of the body, feet shoulder-width apart in a comfortable angle, and looking ahead). For the dynamic condition, subjects were told to step five times with each foot on the plate following the three-step protocol. Both conditions were performed in two testing sessions spaced by 1 week.
Intrasession and intersession reliability for both conditions showed substantial to almost perfect intraclass correlation coefficient (ICC) values, and low coefficient of variation, low standard error measure, and low percentage error. Intrasession ICCs were 0.724 to 0.993 for static condition evaluation and 0.639 to 0.986 for dynamic condition evaluation. Intersession reliability ICCs ranged from 0.850 to 0.987 for the static condition and from 0.781 to 0.996 for the dynamic condition. Coefficient of variation values were below 8% in both cases and percentage error calculated from standard error measure were less than 10%.
The present work demonstrates that the Footwork plantar pressure plate system is a reliable instrument for collecting plantar pressures in static and dynamic conditions. Reliability data were higher for the static trials, probably because of the individual physiologic fluctuations, which are larger during dynamic gait. Reliability for intersession and average intrasession trials were higher than single-test reliability. The results from the present work can be used as a starting point for future research and to establish a basis for sample sizes for investigations that would use the Footwork platform.
Background: A case-control study was conducted to compare static plantar pressures and distribution of body weight across the two lower limbs, as well as the prevalence of gastrocnemius soleus equinus, in children with and without calcaneal apophysitis (Sever’s disease).
Methods: The participants were 54 boys enrolled in a soccer academy, of which eight were lost to follow-up. Twenty-two boys with unilateral Sever’s disease comprised the Sever’s disease group and 24 healthy boys constituted a control group. Plantar pressure data were collected using pedobarography, and gastrocnemius soleus equinus was assessed.
Results: Peak pressure and percentage of body weight supported were significantly higher in the symptomatic feet of the Sever’s disease group than in the asymptomatic feet of the Sever’s disease group and the control group. Every child in the Sever’s disease group had bilateral gastrocnemius equinus, while nearly all children in the control group had no equinus.
Conclusions: High plantar foot pressures are associated with Sever’s disease, although it is unclear whether they are a predisposing factor or a result of the condition. Gastrocnemius equinus may be a predisposing factor for Sever’s disease. Further research is needed to identify other factors involved in the disease and to better understand the factors that contribute to abnormal distribution of body weight in the lower limbs. (J Am Podiatr Med Assoc 101(1): 17–24, 2011)
Background: High peak plantar pressures predispose to foot problems and may exacerbate existing conditions. For podiatric physicians to make educated recommendations to their patients, it is important and necessary to begin to look at different shoes and how they affect peak plantar pressure.
Methods: To determine how flip-flops change peak plantar pressure while walking, we compared peak plantar pressures in the same test subjects wearing flip-flops, wearing athletic shoes, and in bare feet. Ten women with size 7 feet and a body mass index less than 25 kg/m2 were tested with an in-shoe pressure-measurement system. These data were collected and analyzed by one-way analysis of variance and computer software.
Results: Statistically significant results were obtained for nine of the 18 comparisons. In each of these comparisons, flip-flops always demonstrated higher peak plantar pressures than athletic shoes but lower pressures than bare feet.
Conclusion: Although these data demonstrate that flip-flops have a minor protective role as a shock absorber during the gait cycle compared with pressures measured while barefoot, compared with athletic shoes, they increase peak plantar pressures, placing the foot at greater risk for pathologic abnormalities. (J Am Podiatr Med Assoc 98(5): 374–378, 2008)
Background: It is important to determine the plantar pressure distribution of schoolchildren by applying static and dynamic foot analyses using a pedobarography device. However, it is difficult to obtain clear interpretations from results that can be explained by a large number of plantar pressure variables. The aim of this study was to use principal component analysis (PCA) to predict the main components for reducing the size of big data sets, provide a practical overview, and minimize information loss on the subject of plantar pressure assessment in youths.
Methods: In total, 112 schoolchildren were included in the study (mean ± SD: age, 10.58 ± 1.27 years; body mass index, 18.86 ± 4.33). During the research, a pedobarography device was used to obtain plantar pressure data. Each foot was divided into six anatomical regions and evaluated. Global and regional plantar pressure distributions, load and surface areas, pressure-time integrals, weight ratios, and geometric foot properties were calculated.
Results: The PCA yielded ten principal components that together account for 81.88% of the variation in the data set and represent new and distinct patterns. Thus, 137 variables affecting the subject were reduced to ten components.
Conclusions: The numerous variables that affect static and dynamic plantar pressure distributions can be reduced to ten components by PCA, making the research results more concise and understandable.
A randomized controlled study of 19 patients with diabetes mellitus (10 men, 9 women) was undertaken to determine the effects of home exercise therapy on joint mobility and plantar pressures. Of the 19 subjects, 9 subjects performed unsupervised active and passive range-of-motion exercises of the joints in their feet. Each subject was evaluated for joint stiffness and peak plantar pressures at the beginning and conclusion of the study. After only 1 month of therapy, a statistically significant average decrease of 4.2% in peak plantar pressures was noted in the subjects performing the range-of-motion exercises. In the control group, an average increase of 4.4% in peak plantar pressures was noted. Although the joint mobility data revealed no statistically significant differences between the groups, there was a trend for a decrease in joint stiffness in the treatment group. The results of this study demonstrate that an unsupervised range-of-motion exercise program can reduce peak plantar pressures in the diabetic foot. Given that high plantar pressures have been linked to diabetic neuropathic ulceration, it may be possible to reduce the risk of such ulceration with this therapy. (J Am Podiatr Med Assoc 92(9): 483-490, 2002)
Background: We evaluated normal plantar pressures and studied the effect of weight, cadence, and age on forefoot plantar pressures in healthy subjects by using the Biofoot (Instituto de Biomecánica de Valencia, Valencia, Spain) in-shoe measurement system.
Methods: The feet of 45 healthy subjects with no evident foot or lower-limb diseases were measured with the Biofoot in-shoe system. The forefoot was divided into seven areas: the first through fifth metatarsal heads, the hallux, and the second through fifth lesser toes. Three trials of 8 sec each were recorded twice in each subject, and the mean was used to analyze peak and mean plantar pressures. A multiple regression model including weight, age, and cadence was run for each metatarsal head, the hallux, and the lesser toes. Intraclass correlation coefficients and coefficients of variation were also calculated to assess reliability.
Results: The second metatarsal head had the greatest peak (960 kPa) and mean (585.1 kPa) pressures, followed by the third metatarsal head. Weight and cadence combined explained 18% and 23% of peak plantar pressure at the second and third metatarsal heads, respectively (P < .001). The intraclass correlation coefficient varied from 0.76 to 0.96 for all variables. The coefficient of variation between sessions ranged from 5.8% to 9.0%.
Conclusion: The highest peak and mean plantar pressures were found at the second and third metatarsal heads in healthy subjects. Weight, cadence, and age explained a low variability of this pressure pattern. The Biofoot in-shoe system has good reliability to measure plantar pressures. These data will have implications for the understanding of normal foot biomechanics and its determinants. (J Am Podiatr Med Assoc 98(4): 302–310, 2008)
Elevated dynamic plantar pressures are a consistent finding in diabetic patients with peripheral neuropathy, with implications for plantar foot ulceration. This study aimed to investigate whether a first-ray amputation affects plantar pressures and plantar pressure distribution patterns in individuals living with diabetes and peripheral neuropathy.
A nonexperimental matched-subject design was conducted. Twenty patients living with diabetes and peripheral neuropathy were recruited. Group 1 (n = 10) had a first-ray amputation and group 2 (n = 10) had an intact foot with no history of ulceration. Plantar foot pressures and pressure-time integrals were measured under the second to fourth metatarsophalangeal joints, fifth metatarsophalangeal joint, and heel using a pressure platform.
Peak plantar pressures under the second to fourth metatarsophalangeal joints were significantly higher in participants with a first-ray amputation (P = .008). However, differences under the fifth metatarsophalangeal joint (P = .734) and heel (P = .273) were nonsignificant. Pressure-time integrals were significantly higher under the second to fourth metatarsophalangeal joints in participants with a first-ray amputation (P = .016) and in the heel in the control group (P = .046).
Plantar pressures and pressure-time integrals seem to be significantly higher in patients with diabetic peripheral neuropathy and a first-ray amputation compared with those with diabetic neuropathy and an intact foot. Routine plantar pressure screening, orthotic prescription, and education should be recommended in patients with a first-ray amputation.
The Applicability of Plantar Padding in Reducing Peak Plantar Pressure in the Forefeet of Healthy Adults
Implications for the Foot at Risk
Background: We investigated the effectiveness and durability of two types of plantar padding, the plantar metatarsal pad and the single wing plantar cover, which are commonly used for reducing forefoot plantar pressures.
Methods: Mean peak plantar pressure and impulse at the hallux and at the first, second, third, and fourth metatarsophalangeal joints across both feet were recorded using the two-step method in 18 individuals with normal asymptomatic feet. Plantar paddings were retained for 5 days, and their durability and effectiveness were assessed by repeating the foot plantar measurement at baseline and after 3 and 5 days.
Results: The single wing plantar cover devised from 5-mm felt adhesive padding was effective and durable in reducing peak plantar pressure and impulse at the first metatarsophalangeal joint (P = .001 and P = .015, respectively); however, it was not found to be effective in reducing peak plantar pressure and impulse at the hallux (P = .782 and P = .845, respectively). The plantar metatarsal pad was not effective in reducing plantar forefoot pressure and impulse at the second, third, and fourth metatarsophalangeal joints (P = .310 and P = .174, respectively).
Conclusions: These results imply limited applicability of the single wing plantar cover and the plantar metatarsal pad in reducing hallux pressure and second through fourth metatarsophalangeal joint pressure, respectively. However, the single wing plantar cover remained durable for the 5 days of the trial and was effective in reducing the peak plantar pressure and impulse underneath the first metatarsophalangeal joint.
Elevated plantar pressures are an important predictor of diabetic foot ulceration. The objective of this study was to determine which clinical examination variables predict high plantar pressures in diabetic feet. In a cross-sectional study of 152 male veterans with diabetes mellitus, data were collected on demographics, comorbid conditions, disease severity, neuropathy status, vascular disease, and orthopedic and gait examinations. Univariate predictors included height, weight, body surface area, body weight per square inch of foot surface area, bunion deformity, hammer toe, Romberg’s sign, insensitivity to monofilament, absent joint position sense, decreased ankle dorsiflexion, and fat pad atrophy. Variables that remained significantly associated with high plantar pressures (≥4 kg/cm2) in multivariate analysis included height, body weight per square inch of foot surface area, Romberg’s sign, and insensitivity to monofilament. These results may be useful in identifying patients who would benefit from interventions designed to decrease plantar foot pressures. (J Am Podiatr Med Assoc 93(5): 367-372, 2003)