Diabetic foot ulcer incidence in relation to plantar pressure magnitude and measurement location.
ABSTRACT: We 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.Diabetic 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.During 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.Location must be considered when assessing the relationship between PPP and plantar ulceration.
Project description:Elevated dynamic plantar foot pressures significantly increase the risk of foot ulceration in diabetes mellitus. The aim was to determine which factors predict plantar pressures in a population of diabetic patients who are at high-risk of foot ulceration.Patients with diabetes, peripheral neuropathy and a history of ulceration were eligible for inclusion in this cross sectional study. Demographic data, foot structure and function, and disease-related factors were recorded and used as potential predictor variables in the analyses. Barefoot peak pressures during walking were calculated for the heel, midfoot, forefoot, lesser toes, and hallux regions. Potential predictors were investigated using multivariate linear regression analyses. 167 participants with mean age of 63 years contributed 329 feet to the analyses.The regression models were able to predict between 6% (heel) and 41% (midfoot) of the variation in peak plantar pressures. The largest contributing factor in the heel model was glycosylated haemoglobin concentration, in the midfoot Charcot deformity, in the forefoot prominent metatarsal heads, in the lesser toes hammer toe deformity and in the hallux previous ulceration. Variables with local effects (e.g. foot deformity) were stronger predictors of plantar pressure than global features (e.g. body mass, age, gender, or diabetes duration).The presence of local deformity was the largest contributing factor to barefoot dynamic plantar pressure in high-risk diabetic patients and should therefore be adequately managed to reduce plantar pressure and ulcer risk. However, a significant amount of variance is unexplained by the models, which advocates the quantitative measurement of plantar pressures in the clinical risk assessment of the patient.
Project description:High plantar pressures are implicated in the development of diabetes-related foot ulcers. Whether plantar pressures remain high in patients with chronic diabetes-related foot ulcers over time is uncertain. The primary aim of this study was to compare plantar pressures at baseline and three and six months later in participants with chronic diabetes-related foot ulcers (cases) to participants without foot ulcers (controls).Standardised protocols were used to measure mean peak plantar pressure and pressure-time integral at 10 plantar foot sites (the hallux, toes, metatarsals 1 to 5, mid-foot, medial heel and lateral heel) during barefoot walking. Measurements were performed at three study visits: baseline, three and six months. Linear mixed effects random-intercept models were utilised to assess whether plantar pressures differed between cases and controls after adjusting for age, sex, body mass index, neuropathy status and follow-up time. Standardised mean differences (Cohen's d) were used to measure effect size.Twenty-one cases and 69 controls started the study and 16 cases and 63 controls completed the study. Cases had a higher mean peak plantar pressure at several foot sites including the toes (p = 0.005, Cohen's d = 0.36) and mid-foot (p = 0.01, d = 0.36) and a higher pressure-time integral at the hallux (p<0.001, d = 0.42), metatarsal 1 (p = 0.02, d = 0.33) and mid-foot (p = 0.04, d = 0.64) compared to controls throughout follow-up. A reduction in pressure-time integral at multiple plantar sites over time was detected in all participants (p<0.05, respectively).Plantar pressures assessed during gait are higher in diabetes patients with chronic foot ulcers than controls at several plantar sites throughout prolonged follow-up. Long term offloading is needed in diabetes patients with diabetes-related foot ulcers to facilitate ulcer healing.
Project description:BACKGROUND:The prevalence of hallux valgus (HV) increases with age in females. Several studies have investigated the relationship between foot problems, including HV, and falls in older individuals. This study aimed to examine whether HV causes a decline in functional activity in young females and also evaluate the relationship between HV angle, functional activity, toe flexor strength, and plantar pressure. METHODS:We assessed 94 females (mean age, 19.6?±?1.3?years; mean body mass index, 21.2?±?2.0?kg/m2) not currently receiving treatment for lower limb disease. HV angle was determined using their footprint. Functional reach (FR) and maximum step length (MSL), toe flexor strength, and plantar pressure were measured. Plantar pressure was measured during walking. We also calculated FR and the pressure in eight regions (first toe, second through fifth toes, first metatarsal, second through fourth metatarsals, fifth metatarsal, midfoot, medial heel, and lateral heel). RESULTS:There were 39 and 55 participants in the HV and no HV groups, respectively. FR and MSL did not differ significantly between the HV and no HV groups. Toe flexor strength was significantly different between the HV and no HV groups (26.69?±?9.68 vs. 32.19?±?8.55, respectively) (p =?0.002, ??=?0.206). During walking, plantar pressure was significantly lower in the second through fifth toes in the HV group (p =?0.005, ??=?0.187). During FR, plantar pressure was significantly greater in the first metatarsal in the HV group (p =?0.016, ??=?0.338). HV angle was negatively correlated with toe flexor strength (r =?-?0.315, p =?0.002, ??=?0.121) and plantar pressure during walking in the second through fifth toes (r =?-?0.362, p < 0.001, ??=?0.047), and positively correlated with plantar pressure during FR in the first metatarsal (r =?0.308, p =?0.002, ??=?0.137). Toe flexor strength was negatively correlated with plantar pressure during FR in the second through fourth metatarsals (r = -?0.318, p =?0.002, ??=?0.115), and there was a positive correlation with MSL (r = 0.330, p =?0.001, ??=?0.092). CONCLUSIONS:This study confirmed that HV reduces toe flexor strength and affects forefoot pressure during walking and FR in young females. Moreover, the toe flexor strength affects MSL. Efforts to prevent the onset and deterioration of HV from a young age might help reduce the risk of falling when older.
Project description:Quantitative analyses of plantar pressure images typically occur at the group level and under the assumption that individuals within each group display homogeneous pressure patterns. When this assumption does not hold, a personalized analysis technique is required. Yet, existing personalized plantar pressure analysis techniques work at the image level, leading to results that can be unintuitive and difficult to interpret. To address these limitations, we introduce PAPPI: the Personalized Analysis of Plantar Pressure Images. PAPPI is built around the statistical modelling of the relationship between plantar pressures in healthy controls and their demographic characteristics. This statistical model then serves as the healthy baseline to which an individual's real plantar pressures are compared using statistical parametric mapping. As a proof-of-concept, we evaluated PAPPI on a cohort of 50 hallux valgus patients. PAPPI showed that plantar pressures from hallux valgus patients did not have a single, homogeneous pattern, but instead, 5 abnormal pressure patterns were observed in sections of this population. When comparing these patterns to foot pain scores (i.e. Foot Function Index, Manchester-Oxford Foot Questionnaire) and radiographic hallux angle measurements, we observed that patients with increased pressure under metatarsal 1 reported less foot pain than other patients in the cohort, while patients with abnormal pressures in the heel showed more severe hallux valgus angles and more foot pain. Also, incidences of pes planus were higher in our hallux valgus cohort compared to the modelled healthy controls. PAPPI helped to clarify recent discrepancies in group-level plantar pressure studies and showed its unique ability to produce quantitative, interpretable, and personalized analyses for plantar pressure images.
Project description:ObjectivesThis study aimed to compare the plantar loads between habitual rearfoot strike (RFS) and non-RFS (NRFS) during running under the participant’s preferred speed.MethodsA total of 66 (36 RFS, 30 NRFS) healthy amateur male runners were included in our study. In-shoe pressure sensors were utilised to the test plantar loads when participants were running using their preferred foot strike pattern and running speed (RFS: 3.2 ± 0.3 m/s; NRFS: 3.4 ± 0.4 m/s).ResultsResults indicated that running speed has a significant effect on the total contact area [F (1, 64) = 7.061, P = 0.01, ?2 = 0.101], which also affects midfoot and forefoot regions. No significant difference was found on the total maximum force, force-time-integral, peak pressure (PP) and pressure-time-integral (PTI), but the total contact area of RFS was higher than that of NRFS runners [F (1, 64) = 77.406, P < 0.001, ?2 = 0.551]. Plantar loads were mainly focused on the heel and midfoot for RFS runners in all variables, and NRFS runners experienced increased PP and PTI in medial forefoot regions.ConclusionHabitual runners tend to adjust their contact area according to the running speed through midfoot and forefoot regions. RFS runners remain susceptible to high impact force on the heel and midfoot, and NRFS runners experience high impact force in the first metatarsal regions. Therefore, runners should note this situation to avoid running-related injuries.
Project description:There is a well-recognised relationship between body weight, plantar pressures and foot pain, but the temporal association between these factors is unknown. The aim of this study was to investigate the relationships between increasing weight, plantar pressures and foot pain over a two-year period.Fifty-one participants (33 women and 18 men) completed the two-year longitudinal cohort study. The sample had a mean (standard deviation (SD)) age of 52.6 (8.5) years. At baseline and follow-up, participants completed the Manchester Foot Pain and Disability Index questionnaire, and underwent anthropometric measures, including body weight, body mass index, and dynamic plantar pressures. Within-group analyses examined differences in body weight, foot pain and plantar pressures between baseline and follow up, and multivariate regression analysis examined associations between change in body weight, foot pain and plantar pressure. Path analysis assessed the total impact of both the direct and indirect effects of change in body weight on plantar pressure and pain variables.Mean (SD) body weight increased from 80.3 (19.3), to 82.3 (20.6) kg, p = 0.016 from baseline to follow up. The change in body weight ranged from -16.1 to 12.7 kg. The heel was the only site to exhibit increased peak plantar pressures between baseline and follow up. After adjustment for age, gender and change in contact time (where appropriate), there were significant associations between: (i) change in body weight and changes in midfoot plantar pressure (B = 4.648, p = 0.038) and functional limitation (B = 0.409, p = 0.010), (ii) plantar pressure change in the heel and both functional limitation (B = 4.054, p = 0.013) and pain intensity (B = 1.831, p = 0.006), (iii) plantar pressure change in the midfoot and both functional limitation (B = 4.505, p = 0.018) and pain intensity (B = 1.913, p = 0.015). Path analysis indicated that the effect of increasing body weight on foot-related functional limitation and foot pain intensity may be mediated by increased plantar pressure in the midfoot.These findings suggest that as body weight and plantar pressure increase, foot pain increases, and that the midfoot may be the most vulnerable site for pressure-related pain.
Project description:BACKGROUND:Pes planus (flatfoot) is a common deformity characterized by the midfoot arch collapses during walking. As the midfoot is responsible for shock absorption, persons with flatfoot experience increased risk of injuries such as thumb valgus, tendinitis, plantar fasciitis, metatarsal pain, knee pain, lower-back pain with prolonged uphill, downhill, and level walking, depriving them of the physical and mental health benefits of walking as an exercise. METHODS:Fifteen female college students with flatfoot were recruited. A wireless plantar-pressure system was used to measure the stance time, cadence, plantar pressure, and contact area. Parameters were compared between wearing flat and arch-support insoles using a two-way repeated measures ANOVA with on an incline, decline, and level surface, respectively. The significance level ? was set to 0.05. The effect size (ES) was calculated as a measure of the practical relevance of the significance using Cohen's d. RESULTS:On the level surface, the stance time in the arch-support insole was significantly shorter than in the flat insole (p<0.05; ES = 0.48). The peak pressure of the big toe in the arch-support insole was significantly greater than in the flat insole on the uphill (p<0.05; ES = 0.53) and level surfaces (p<0.05; ES = 0.71). The peak pressure of the metatarsals 2-4 and the contact area of the midfoot in the arch-support insole were significantly greater than in the flat insole on all surfaces (all p< 0.05). CONCLUSIONS:These results imply that wearing an arch-support insole provides benefits in the shortened stance time and generation of propulsion force to the big toe while walking on uphill and level surfaces and to the metatarsals 2-4 while walking on the level surface. More evenly distributed contact areas across the midfoot may help absorb shock during uphill, downhill and level walking.
Project description:<h4>Background</h4>The effectiveness of foot orthoses has been evaluated in many clinical trials with sham foot orthoses used as the control intervention in at least 10 clinical trials. However, the mechanical effects and credibility of sham orthoses has been rarely quantified. This study aimed to: (i) compare the effects on plantar pressures of three sham foot orthoses to a customised foot orthosis, and (ii) establish the perceived credibility and the expected benefit of each orthotic condition.<h4>Methods</h4>Thirty adults aged between 18 and 51 participated in this study. At 0 and 4 weeks, plantar pressure data were collected for the heel, midfoot and forefoot using the pedar(®)-X in-shoe system for the following five randomly assigned conditions: (i) shoe alone, (ii) customised foot orthosis, (iii) contoured polyethylene sham foot orthosis, (iv) contoured EVA sham foot orthosis, and (v) flat EVA sham foot orthosis. At the initial data collection session, each participant completed a Credibility/Expectancy Questionnaire (CEQ) to determine the credibility and expected benefit of each orthotic condition.<h4>Results</h4>Compared to the shoe alone at week 0, the contoured polyethylene sham orthosis was the only condition to not significantly effect peak pressure at any region of the foot. In contrast, the contoured EVA sham orthosis, the flat EVA sham orthosis and the customised orthosis significantly reduced peak pressure at the heel. At the medial midfoot, all sham orthoses provided the same effect as the shoe alone, which corresponded to effects that were significantly different to the customised orthosis. There were no differences in peak pressure between conditions at the other mask regions, the lateral midfoot and forefoot. When the conditions were compared at week 4, the differences between the conditions were generally similar to the findings observed at week 0. With respect to credibility and expected benefit, all orthotic conditions were considered the same with the exception of the contoured polyethylene sham orthosis, which was perceived as being less credible and less likely to provide benefits.<h4>Conclusion</h4>The findings of this study indicate that all of the sham orthoses tested provided the same effect on plantar pressures at the midfoot and forefoot as a shoe alone. However, the contoured EVA sham orthosis and the flat EVA sham orthosis significantly reduced peak pressure under the heel, which was similar to the customised orthosis. In contrast, the contoured polyethylene sham orthosis had no significant effect on plantar pressure and was comparable to the shoe alone at all regions of the foot. Hence, lower plantar pressures were found under the heel with some sham orthoses, but not with others. Importantly, participants perceived the polyethylene sham orthosis - the sham that had no effect on plantar pressure - to be the least credible orthosis and the least likely to provide benefits. This may be critical for the design of future clinical trials as it may introduce confounding effects that produce inaccurate results. These findings provide some evidence for the mechanical effects, treatment credibility and expected benefit of sham foot orthoses, which should be considered when they are used as a control intervention in a clinical trial.
Project description:BACKGROUND:The aim of the study was to evaluate changes in plantar pressure distribution in feet affected by hallux valgus compared with their contralateral non-affected feet and with the feet of healthy control subjects. METHODS:Thirty-six patients with unilateral hallux valgus who were indicated for surgery and 30 healthy subjects were assessed on a pedobarographic instrumented treadmill for step length and width, mean stance phase, and plantar foot pressure distribution. Plantar pressure distribution was divided into eight regions. RESULTS:Significantly higher plantar pressures were observed in hallux valgus feet under the second and third metatarsal heads (p =?.033) and the fourth and fifth toes (p <?.001) than in the healthy control feet. Although decreased pressures were measured under the hallux in affected feet (197 [82-467] kPa) in contrast to the contralateral side (221 [89-514] kPa), this difference failed to reach statistical significance (p =?.055). The gait parameters step width, step length, and single-limb support did not show any differences between hallux valgus and control feet. CONCLUSION:Although the literature on changes in plantar pressures in hallux valgus remains divided, our findings on transferring load from the painful medial to the central and lateral forefoot region are consistent with the development of transfer metatarsalgia in patients with hallux valgus.
Project description:There is a large amount of information regarding risk factors for fifth metatarsal stress fractures; however, there are few studies involving large numbers of subjects. This study aimed to compare the static foot alignment and distribution of foot pressure of athletes with and without a history of fifth metatarsal stress fractures.The study participants comprised 335 collegiate male soccer players. Twenty-nine with a history of fifth metatarsal stress fractures were in the fracture group and 306 were in the control group (with subgroups as follows: 30 in the fracture foot group and 28 in the non-fracture group). We measured the foot length, arch height, weight-bearing leg-heel alignment, non-weight-bearing leg-heel alignment, forefoot angle relative to the rearfoot, forefoot angle relative to the horizontal axis, and foot pressure.The non-weight-bearing leg-heel alignment was significantly smaller and the forefoot angle relative to the rearfoot was significantly greater in the fracture foot group than in the control foot group (P = 0.049 and P = 0.038, respectively). With regard to plantar pressure, there were no significant differences among the groups. Midfield players had significantly higher rates of fifth metatarsal stress fracture in their histories, whereas defenders had significantly lower rates (chi-square = 13.2, P < 0.05). There were no significant differences in the frequency of fifth metatarsal stress fractures according to the type of foot (kicking foot vs. pivoting foot) or the severity of ankle sprain.Playing the midfield position and having an everted rearfoot and inverted forefoot alignment were associated with fifth metatarsal stress fractures. This information may be helpful for preventing fifth metatarsal stress fracture recurrence. More detailed load evaluations and a prospective study are needed in the future.