Background: The path of the center of pressure during walking varies among individuals by deviating to a greater or lesser extent toward the medial or lateral border of the foot. It is unclear whether this variance is systematic and is affected by foot posture. The aim of this study was to explore the relationship between foot morphology and center-of-pressure excursion during barefoot walking.
Methods: Pressure data were collected from 83 participants whose foot type had been classified as supinated, normal, or pronated according to the Foot Posture Index. Three center-of-pressure variables were analyzed: medial excursion area, lateral excursion area, and total excursion area.
Results: Across the spectrum of foot types, we found that the more supinated a participant’s foot posture, the larger the area of lateral center-of-pressure excursion, and, conversely, the more pronated the foot posture, the smaller the area of lateral center-of-pressure excursion. Furthermore, the supinated foot type had a relatively larger center-of-pressure total excursion area, and the pronated foot type had a relatively smaller center-of-pressure total excursion area.
Conclusions: These results indicate the importance of assessing foot posture when measuring center of pressure and may help explain regional differences in pain and injury location among foot types. (J Am Podiatr Med Assoc 98(2): 112–117, 2008)
Forefoot nerve entrapments are common, and they are usually mistakenly categorized under the misnomer of “Morton’s neuroma.” Although the complete etiology of these forefoot entrapments is still not known, exogenous mechanical factors must be considered when patients present with clinical signs of forefoot nerve entrapment. It has been well established that equinus deformity can increase plantar forefoot pressures. This article provides a brief overview of equinus deformity as it relates to forefoot pathology, specifically, its mechanical contribution to forefoot nerve entrapment, and the use of endoscopic gastrocnemius recession for the treatment of forefoot nerve entrapment. (J Am Podiatr Med Assoc 95(5): 464–468, 2005)
Lateral wedges are a common intervention used to alter biomechanical function of the lower limb. Although there is evidence investigating the use and impact of lateral wedges in individuals with medial knee osteoarthritis, knowledge of how these wedges affect foot function in healthy adults is limited. Therefore, this study intends to investigate how lateral wedging affects foot function in healthy adults and, furthermore, how wedge design influences the outcome. The framework outlined by Arksey and O’Malley was used for this scoping review. To ensure methodologic quality and transparent reporting, the study adheres to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews preferred reporting guidelines. A systematic search was conducted using MEDLINE by means of EBSCO; SPORT Discuss; CINAHL; AMED by means of OVID; and Scopus. The initial search yielded 252 articles in total; 21 studies were included in the final analysis. Significant incongruence exists in descriptions of wedge length among the 21 included studies. Thirteen studies (61%) reported using full-length wedges, five studies did not report wedge length, and only one study analyzed more than one wedge length. Ethylene vinyl acetate was the most common material, and reporting of hardness was inconsistent. A broad range of inclination angles were used, with limited explanation for why these values were selected. All but one study that analyzed ankle/subtalar joint frontal plane moments reported an increase in the external eversion moment. The review identified significant variation in the design of wedges used within this body of work and a lack of investigation into the influence of wedge design. Wedge design appears to be a secondary consideration, with very few studies examining multiple material types or wedge placements. All but one of the included studies reported a significant change in ankle/subtalar joint moments with lateral wedging. Unfortunately, further generalization was not possible because of the inconsistency and variation.
The Foot Posture Index (FPI) quantifies foot posture on the basis of six criteria. Although the male foot is longer and broader than the female foot, limited evidence exists about the differences in foot posture between the sexes and which are its biological and anthropometric determinants. We sought to evaluate possible sex differences in the FPI and the determinants influencing foot posture.
In 400 individuals (201 men and 199 women), the FPI was determined in the static bipedal stance and relaxed position. The FPI was obtained as the sum of the scores (−2, −1, 0, 1, or 2) given to each of six criteria. A multiple regression model was constructed of the overall FPI against age, weight, height, body mass index, and foot size.
The mean ± SD FPI was 2.0 ± 4.3 overall, 1.6 ± 4.5 for men, and 2.4 ± 4.1 for women, with the difference being nonsignificant (P = .142). The neutral posture was the most frequent (57.3%). A greater proportion of women had neutral and pronated feet, and a greater proportion of men had supinated and highly supinated feet, with the differences being nonsignificant (P = .143). Foot size, height, and body mass index together explained 10.1% of the overall FPI value (P < .001).
The most frequent posture was neutral with a certain degree of pronation, with no differences in FPI values between men and women. Participants with larger foot sizes had higher FPI values, whereas taller and heavier participants had lower FPI values. (J Am Podiatr Med Assoc 103(5): 400–404, 2013)
We sought to identify the biomechanical characteristics of the feet of patients with diabetes mellitus and the interrelationship with diabetic neuropathy by determining the range of joint mobility and the presence and locations of calluses and foot deformities.
This observational comparative study involved 281 patients with diabetes mellitus who underwent neurologic and vascular examinations. Joint mobility studies were performed, and deformities and hyperkeratosis locations were assessed.
No substantial differences were found between patients with and without neuropathy in joint mobility range. Neuropathy was seen as a risk factor only in the passive range of motion of the first metatarsophalangeal joint (mean ± SD: 57.2° ± 19.5° versus 50.3° ± 22.5°, P = .008). Mean ± SD ankle joint mobility values were similar in both groups (83.0° ± 5.2° versus 82.8° ± 9.3°, P = .826). Patients without neuropathy had a higher rate of foot deformities such as hallux abductus valgus and hammer toes. There was also a higher presence of calluses in patients without neuropathy (82.8% versus 72.6%; P = .039).
Diabetic neuropathy was not related to limited joint mobility and the presence of calluses. Patients with neuropathy did not show a higher risk of any of the deformities examined. These findings suggest that the etiology of biomechanical alterations in diabetic people is complex and may involve several anatomically and pathologically predisposing factors. (J Am Podiatr Med Assoc 101(3): 208–214, 2011)
Sever's disease is a common cause of pain in growing kids. Many papers reported in the literature discuss this pathologic condition, but no consensus regarding its etiology has been found among researchers. The aim of the present study was to describe the epidemiologic profile and associated factors of 430 athletic children in a population-based sample of soccer (29.5%), basketball (48.1%), and volleyball (22.3%) players aged 6 to 14 years.
Every athlete was evaluated through physical examination, the Foot Posture Index (FPI), the Oxford Ankle Foot Questionnaire, and a custom-made sports questionnaire.
These data show that body mass index, sex, terrain type, sports discipline, and FPI should not be considered as risk factors for calcaneal apophysitis, whereas a significantly higher risk has been found in younger individuals (P < .01), in those with fewer training sessions per week (P = .02), and in those with shorter training sessions (P < .01).
The prevalence of Sever's disease in the athletic children evaluated in the present study was higher in younger and less active patients, whereas no differences were registered by sex, FPI, body mass index, terrain type, or sports discipline.
The purpose of this study was to identify the clinical and plantar loading variables related to hallux valgus. Fifty-one healthy control subjects and 40 subjects with a diagnosis of moderate hallux valgus deformity of similar age and body weight were recruited for this study. Clinical measurements of pain, first metatarsophalangeal joint range of motion, and single-leg resting calcaneal stance position were obtained. Biomechanical measurements were obtained using a capacitive pressure platform. Plantar loading variables were calculated for seven regions of the plantar surface. A univariate analysis followed by a stepwise logistic regression was used to analyze the data. The results indicated that high values for pain, single-leg resting calcaneal stance position, hallux region peak pressure and force–time integral, and central forefoot region force–time integral increased the likelihood of hallux valgus. (J Am Podiatr Med Assoc 93(2): 97-103, 2003)
The low-Dye strap is used routinely to temporarily control pronation of the foot and, thereby, to diagnose and treat pronatory sequelae. However, the exact biomechanical effects of this strapping technique on the foot are not well documented. The main purpose of this study was to establish the specific mechanical effects of the low-Dye strap on the pronatory foot. Within this context, the specific aim was to assess the effect of the low-Dye strap on three distinct pronation-sensitive mechanical attributes of the foot in the weightbearing state: 1) calcaneal eversion, 2) first metatarsophalangeal joint range of motion, and 3) medial longitudinal arch height. Weightbearing measurements of these three attributes were made before and after application of a low-Dye strap, and statistical comparisons were made. The results of this study indicate that the low-Dye strap is effective in reducing calcaneal eversion, increasing first metatarsophalangeal joint range of motion, and increasing medial longitudinal arch height in the weightbearing state. Knowledge of the exact mechanisms of action of the low-Dye strap will provide practitioners with greater confidence in the use of this modality. (J Am Podiatr Med Assoc 93(2): 118-123, 2003)
This study compares the potential benefit of fifth metatarsal head resection versus standard conservative treatment of plantar ulcerations in people with diabetes mellitus. Using a retrospective cohort model, we abstracted data from 40 patients (22 cases and 18 controls) treated for uninfected, nonischemic diabetic foot wounds beneath the fifth metatarsal head. There were no significant differences in sex, age, duration of diabetes mellitus, or degree of glucose control between cases and controls. Patients who underwent a fifth metatarsal head resection healed significantly faster (mean ± SD, 5.8 ± 2.9 versus 8.7 ± 4.3 weeks). Patients were much less likely to reulcerate during the period of evaluation in the surgical group (4.5% versus 27.8%). The results of this study suggest that fifth metatarsal head resection is a potentially effective treatment in patients at high risk of ulceration and reulceration. (J Am Podiatr Med Assoc 95(4): 353–356, 2005)
Anthropometric status can influence gait biomechanics, but there is relatively little published research regarding foot and ankle characteristics in the obese pediatric population. We sought to compare the structural and functional characteristics of the foot and ankle complex in obese and non-obese children.
Twenty healthy children (ten obese and ten normal weight) were recruited for a cross-sectional research study. Anthropometric parameters were measured to evaluate active ankle dorsiflexion, arch height (arch height index, arch rigidity index ratio, and arch drop), foot alignment (resting calcaneal stance position and forefoot-rearfoot alignment in unloaded and loaded positions), and foot type (malleolar valgus index). Independent t tests determined significant differences between groups for all assessed parameters. Statistical significance was set at P < .0125.
Compared with non-obese participants, obese participants had significantly greater arch drop (mean ± SD: 5.10 ± 2.13 mm versus 2.90 ± 1.20 mm; P =.011) and a trend toward lower arch rigidity index ratios (mean ± SD: 0.92 ± 0.03 versus 0.95 ± 0.02; P = .013). In addition, obese participants had significantly less active ankle dorsiflexion at 90° of knee flexion versus non-obese participants (mean ± SD: 19.57 ± 5.17 versus 29.07 ± 3.06; P < .001). No significant differences existed between groups for any other anthropometric measurements.
The decreased active ankle dorsiflexion in the obese group can increase foot contact for a longer period of the stance phase of gait. Obese participants also presented with a more flexible foot when bearing weight. (J Am Podiatr Med Assoc 102(1): 5–12, 2012)