Search Results
Abstract
Objectives: To examine the effects of foot dominance and body mass on foot plantar pressures in older women of regular, overweight, and obese weights.
Methods: 96 female adults were divided into regular-weight group (68.30 ± 4.19 yr), overweight group (69.88 ± 3.76 yr), and obesity group (68.47 ± 3.67 yr) based on their body mass index scores. Footscan® plantar pressure test system was used to assess the dynamic plantar pressures, and parameters were collected from risk analysis, foot axis analysis, single foot timing analysis, and pressure analysis.
Results: (1) The local risks of lateral forefoot and midfoot, the minimum and maximum subtalar joint angles, the flexibility of subtalar joint, foot flat phase, as well as the average pressures on toes, metatarsals,, midfoot, and lateral heel, with the peak pressures on toe 2–5, metatarsal 2, metatarsal 5, midfoot, and lateral heel had significant within-subject differences. (2) The phases of initial contact and foot flat, the average pressures on toe 2–5, metatarsals, midfoot, and heels, with the peak pressures on metatarsal 1–4, midfoot, and heels exhibited significant between-subjects differences. (3) There was an interaction effect of foot dominance and body mass index on the flexibility of subtalar joint.
Conclusions: The non-dominant foot works better for stability, especially when touching on and off the ground. The dominant foot works better for propulsion but is more susceptible to pain, injury, and falls. For obese older women, the forefoot and midfoot are primarily responsible for maintaining stability, but the lateral midfoot and hindfoot are more prone to pain and discomfort.
Background
Different closed kinematic tasks may present different magnitudes of knee abduction, foot pronation, and foot plantar pressure and area. Although there are plenty of studies comparing knee abduction between different tasks, the literature lacks information regarding differences in foot pronation and foot plantar pressure and area. We compared foot angular displacement in the frontal plane and foot plantar pressure and area among five closed kinematic tasks.
Methods
Forefoot and rearfoot angular displacement and foot plantar pressure and area were collected in 30 participants while they performed the following tasks: stair descent, single-leg step down, single-leg squat, single-leg landing, and drop vertical jump. Repeated-measures analyses of variance were used to investigate differences between tasks with α = 0.05.
Results
Single-leg squat and stair descent had increased foot total plantar area compared with single-leg landing (P = .005 versus .027; effect size [ES] = 0.66), drop vertical jump (P = .001 versus P = .001; ES = 0.38), and single-leg step down (P = .01 versus P = .007; ES = 0.43). Single-leg landing and single-leg step down had greater foot total plantar area compared with drop vertical jump (P = .026 versus P = .014; ES = 0.54). There were differences also in rearfoot and midfoot plantar area and pressure and forefoot plantar pressure.
Conclusions
Differences in foot-striking pattern, magnitude of ground reaction force, and task speed might explain these findings. Clinicians should consider these findings to improve decisions about tasks used during rehabilitation of patients with foot conditions.
Hallux Valgus Plantar Pressure Distribution Before and After Surgery
A Systematic Review
Hallux valgus is a common foot deformity that may cause pain and functional limitation, and often requires surgical correction. Clinical and radiographic parameters are typically used to assess postoperative outcomes. Plantar pressure distribution systems represent an innovative additional tool to evaluate hallux functional outcome after surgery. A systematic review of the current literature was performed to assess evaluation systems used for plantar pressure analysis and differences before and after hallux valgus surgery, and a possible relationship between different surgical techniques and clinical and radiographic results. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were used for this review. Initial search results yielded 40 studies. Two additional studies were found through cross-reference. Twenty-five studies were screened. A total of 10 articles were included in the review process. Two main plantar pressure analysis systems were identified. Hallux function restoration based on plantar pressure measurement did not always occur. No relevant relationships between plantar pressure distribution data and different surgical techniques were established. All patients achieved satisfactory clinical and radiographic outcomes, regardless of surgical techniques used; however, no clear relationships were observed between clinical and radiographic results and the change in foot plantar pressure patterns. The current literature on this topic showed several methodologic limitations. Therefore, it is not possible to provide sufficiently supported evidence-based data regarding plantar pressure distribution rebalance after surgery using current plantar pressure analysis systems. Further investigations are needed to fill these gaps in evidence.
Background:
Clinical recommendations for the prevention and healing of diabetic foot ulcers (DFUs) are somewhat clear. However, assessment and quantification of the mechanical stress responsible for DFU remain complex. Different pressure variables have been described in the literature to better understand plantar tissue stress exposure. This article reviews the role of pressure and shear forces in the pathogenesis of plantar DFU.
Methods:
We performed systematic searches of the PubMed and Embase databases, completed by a manual search of the selected studies. From 535 potentially relevant references, 70 studies were included in the full-text review.
Results:
Variables of plantar mechanical stress relate to vertical pressure, shear stress, and temporality of loading. At this time, in-shoe peak plantar pressure (PPP) is the only reliable variable that can be used to prevent DFU. Although it is a poor predictor of in-shoe PPP, barefoot PPP seems complementary and may be more suitable when evaluating patients with diabetes mellitus and peripheral neuropathy who seem noncompliant with footwear. An in-shoe PPP threshold value of 200 kPa has been suggested to prevent DFU. Other variables, such as peak pressure gradient and peak maximal subsurface shear stress and its depth, seem to be of additional utility.
Conclusions:
To better assess the at-risk foot and to prevent ulceration, the practitioner should integrate quantitative models of dynamic foot plantar pressures, such as in-shoe and barefoot PPPs, with the regular clinical screening examination. Prospective studies are needed to evaluate causality between other variables of mechanical stress and DFUs. (J Am Podiatr Med Assoc 103(4): 322–332, 2013)
Background:
Rocker shoes are commonly prescribed to healthy and pathologic populations to decrease stress on the lower limbs. An optimal rocker shoe design must consider both toe and heel rockers. Heel rockers are as effective as toe rockers in relieving foot plantar pressures. However, most studies have focused on the position of toe rockers. The aim of this study was to assess the effect of different heel rocker apex placements on lower-limb kinetics and kinematics.
Methods:
Eighteen healthy females participated in this study. Three pairs of rocker shoes with rocker apex positions anterior to the medial malleolus (shoe A), at the medial malleolus (shoe B), and posterior to the medial malleolus (shoe C) were fabricated and then compared with a flat shoe (shoe D). Kinetic and kinematic data were collected, and lower-extremity joint ranges of motion and moments were calculated.
Results:
Ankle range of motion was increased by shoe C (P = .04) during initial contact and by shoe A (P = .02) during single-limb support. Peak knee moment was significantly larger for shoes A and B (P < .05) during single-limb support.
Conclusions:
Results showed that forward and backward shifting of the heel rocker apex could change the knee moment and ankle joint range of motion in the stance phase of gait. Therefore, placement of the heel rocker in a rocker-bottom shoe can be manipulated to promote the desired lower-limb motion, at least in healthy individuals.
Is TCC-EZ a Suitable Alternative to Gold Standard Total-Contact Casting?
A Plantar Pressure Analysis
Background
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.
Methods
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.
Results
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.
Conclusions
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.
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: Muscle disorders may cause a change in plantar pressures by the misalignment on the foot during gait phases. Therefore, corns or calluses develop at the plantar regions, and diabetic foot ulcers follow for severe cases, although it can be prevented and even treated by podiatric approaches with patient-specific therapeutic insoles and footwear. Although the importance of a threshold value of 200 kPa in peak plantar pressure reduction has been highlighted as a standard to prevent reulceration in the diabetic foot, it may not be possible to ensure this pressure reduction for each patient.
Methods: In this study, three types of ethylene-vinyl acetate have been used to optimize the off-loading performance for predetermined early-stage diabetic foot ulcer scenarios by means of baropodometric plantar pressure analyses and finite element method for each gait phase.
Results: The total cost of the manufacturing for this study was reduced to $10.26 and it was performed in 24.6 minutes. In addition, the off-loaded pressure was increased by 2.3 times and the volume of the off-loading geometry was increased 8.12 times based on the foam polymer used.
Conclusions: Consequently, improved off-loading was obtained and a standard was proposed for the first time to calculate the off-loading performance before manufacturing of the therapeutic insole model to ensure a better recovery period.
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.
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)
