Search Results
Casting Methods and Plantar Pressure
Effects of Custom-made Foot Orthoses on Dynamic Plantar Pressure Distribution
Foot orthoses are widely used to treat various foot problems. A literature search revealed no publications on differences in plantar pressure distribution resulting from casting methods for foot orthoses. Four casting methods were used for construction of orthoses. Two foam box techniques were used: accommodative full weightbearing method (A) and functional semiweightbearing method (B). Also, two suspension plaster casting techniques were used: accommodative casting (C) and functional subtalar joint neutral position (Root) method (D). Their effects on contact area, plantar pressure, and walking convenience were evaluated. All orthoses increased the total contact area (mean, 17.4%) compared with shoes without orthoses. Differences in contact areas between orthoses for total plantar surface were statistically significant. Peak pressures for the total plantar surface were lower with orthoses than without orthoses (mean, 22.8%). Among orthoses, only the difference between orthoses A and B was statistically significant. Differences between orthoses for the forefoot were small and not statistically significant. The gait lines of the shoe without an insole and of the accommodative orthoses are more medially located than those of functional orthoses. Walking convenience in the shoe was better rated than that with orthoses. There were no differences in perception of walking convenience between orthoses A, B, and C. Orthosis D had the lowest convenience rating. The four casting methods resulted in differences between orthoses with respect to contact areas and walking convenience but only slight differences in peak pressures. (J Am Podiatr Med Assoc 96(1): 9–18, 2006)
Background: During pregnancy, physical and hormonal modifications occur. Morphologic alterations of the feet are found. These observations can induce alterations in plantar pressure. This study sought to investigate plantar pressures during gait in the last 4 months of pregnancy and in the postpartum period. A comparison with nulliparous women was conducted to investigate plantar pressure modifications during pregnancy.
Methods: Fifty-eight women in the last 4 months of pregnancy, nine postpartum women, and 23 healthy nonpregnant women (control group) performed gait trials on an electronic walkway at preferred speeds. The results for the three groups were compared using analysis of variance.
Results: During pregnancy, peak pressure and contact area decreased for the forefoot and rearfoot. These parameters increased significantly for the midfoot. The gait strategy seemed to be lateralization of gait with an increased contact area of the lateral midfoot and both reduced pressure and a later peak time on the medial forefoot. In the postpartum group, footprint parameters were modified compared with the pregnant group, indicating a trend toward partial return to control values, although differences persisted between the postpartum and control groups.
Conclusions: Pregnant women had altered plantar pressures during gait. These findings could define a specific pattern of gait footprints in late pregnancy because plantar pressures had characteristics that could maintain a stable and safe gait.
High Plantar Pressure and Callus in Diabetic Adolescents
Incidence and Treatment
This study examined the incidence of high peak plantar pressure and plantar callus in 211 adolescents with diabetes mellitus and 57 nondiabetic controls. The percentage of subjects with these anomalies was the same in both groups. Although diabetic subjects were no more likely than nondiabetic controls to have high peak plantar pressure and callus, these anomalies place individuals with diabetes at greater risk of future foot problems. The effects of orthoses, cushioning, and both in combination were monitored in 17 diabetic subjects with high peak plantar pressure and in 17 diabetic subjects with plantar callus; reductions of up to 63% were achieved. Twelve-month follow-up of diabetic subjects fitted with orthoses showed a significant reduction in peak plantar pressure even when the orthoses were removed. The diabetic subjects who had not received any interventions during the same 12-month period showed no significant change in peak plantar pressure. (J Am Podiatr Med Assoc 93(3): 214-220, 2003)
Assessing Plantar Pressure Distribution in Children with Flatfoot Arch
Application of the Clarke Angle
Background
Flatfoot, or pes planus, is one of the most common foot posture problems in children that may lead to lower-extremity pain owing to a potential increase in plantar pressure. First, we compared plantar pressure distribution between children with and without flatfoot. Second, we examined the reliability and accuracy of a simple metric for characterization of foot posture: the Clarke angle. Third, we proposed a mathematical model to predict plantar pressure magnitude under the medial arch using body mass and the Clarke angle.
Methods
Sixty children with flatfoot and 33 aged-matched controls were recruited. Measurements included in-shoe plantar pressure distribution, ground reaction force, Clarke angle, and radiography assessment. The measured Clarke angle was compared with radiographic measurements, and its test-retest reliability was determined. A mathematical model was fitted to predict plantar pressure distribution under the medial arch using easy-to-measure variables (body mass and the Clarke angle).
Results
A high correlation was observed between the Clarke angle and radiography measurements (r > 0.9; P < 10−6). Excellent between- and within-day test-retest reliability for Clarke angle measurement (intraclass correlation coefficient, >0.9) was observed. Results also suggest that pressure magnitude under the medial arch can be estimated using the Clarke angle and body mass (R 2 = 0.95; error, <0.04 N/cm2 [2%]).
Conclusions
This study suggests that the Clarke angle is a practical, reliable, and sensitive metric for quantification of medial arch height in children and could be recommended for research and clinical applications. It can also be used to estimate plantar pressure under the medial arch, which, in turn, may assist in the timely intervention and prognosis of prospective problems associated with flatfoot posture.
In-Shoe Plantar Pressure Profiles in Amateur Basketball Players
Implications for Footwear Recommendations and Orthosis Use
Background:
Biomechanical analysis of foot loading characteristics may provide insights into the injury mechanisms and guide orthotic prescription for basketball players. This study aimed to quantify in-shoe plantar pressure profiles in amateur players when executing typical basketball movements.
Methods:
Twenty male university basketball players performed four basketball-specific movement tasks—running, maximal forward sprinting, maximal 45° cutting, and layup—in a pair of standardized basketball shoes fitted with an in-shoe plantar pressure measurement system. Peak pressure (PP) and pressure-time integral (PTI) data were extracted from ten plantar regions. One-way repeated-measures analysis of variance was performed across the tasks, with significance set at P < .05.
Results:
Distinct plantar pressure distribution patterns were observed among the four movements. Compared with running, significantly higher (P < .05) PP and PTI of up to approximately 55% were found in sprinting and layup, particularly at the forefoot region. Similarly, significantly higher (P < .05) PPs and PTIs, ranging from approximately 23% to 90%, were observed in 45° cutting compared with running at most foot regions.
Conclusions:
Compared with running, sprinting and layup demonstrated higher plantar loading in the forefoot region, and 45° cutting yielded increased plantar loading in most regions of the foot. Understanding the plantar pressure characteristics of different movements may be useful in optimizing footwear designs, orthosis use, or training strategies to minimize regional plantar loading during amateur basketball play.
Contralateral Peak Plantar Pressures with a Postoperative Boot
A Preliminary Study
Background: Frequent use of walking boots in podiatric medicine often elicits patient complaints and sequelae from the imposed limb-length discrepancy. This study was designed primarily to determine whether peak plantar pressures are decreased in the contralateral foot when a moderately worn athletic shoe is worn opposite a high-calf walking boot and, if so, secondarily to determine whether a specialized surgical shoe worn on the contralateral foot can also effectively reduce this pressure. The pressure reductions were then compared to determine whether significantly greater plantar pressure reduction was provided by either the athletic shoe or the surgical shoe.
Methods: Participants without a foot abnormality walked on a treadmill in four footwear combinations: barefoot bilaterally, high-calf rocker-bottom sole (HCRB) walking boot/ barefoot, HCRB walking boot/athletic shoe, and HCRB walking boot/modified walking boot shoe. Measurements were taken with the participants wearing socks. Peak plantar calcaneal pressures were collected.
Results: Peak plantar pressures under the calcaneus opposite the HCRB walking boot were significantly reduced from barefoot pressures when either an athletic shoe or the modified walking boot shoe was worn. However, no significant difference was seen when comparing the reduction by the athletic shoe with that by the modified walking boot.
Conclusions: Wearing an athletic shoe on the foot opposite an HCRB walking boot reduces calcaneal pressures; however, wearing a modified device with structural properties of an HCRB walking boot sole is no better than an athletic shoe at reducing peak calcaneal pressures. (J Am Podiatr Med Assoc 101(2): 127–132, 2011)
Background
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.
Methods
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.
Results
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%.
Conclusions
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: 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)
