Rheumatoid arthritis (RA) often affects feet with progressive pathologic changes to foot morphology and pressure distribution. Studies in RA suggest that reductions in forefoot peak pressures can reduce pain. We investigated the effects of off-the-shelf foot orthoses on plantar foot pressures in patients with early RA.
Thirty-five patients with early RA were recorded walking. Variables measured were forefoot peak plantar pressure (PPPft), forefoot pressure-time integral (PTIft), and hallux and lesser toe and midfoot contact areas. Patients were analyzed while walking barefoot, with shoes, and with shoes and foot orthoses. Measurements were taken at baseline and at 3 and 6 months.
There were significantly increased PPPft values between barefoot and shod and between barefoot and orthoses (P < .01). However, there was a significant reduction in PPPft during the 6 months with orthoses compared with shoes only (P < .01). Foot orthoses significantly reduced PTIft over 6 months (P < .01). Results also demonstrated a significant increase in hallux and lesser toe (P < .01) and midfoot (P < .01) contact areas during the 6 months with foot orthoses.
In patients with early RA, off-the-shelf foot orthoses cause a significant reduction of 22% in PPPft and 14% in PTIft as soon as insoles are worn compared with shod. Further reductions for orthoses compared with baseline were found by 3 months (15% in PPPft and 14% in PTIft) and 6 months (33% in PPPft and 33% in PTIft). These findings could contribute to reductions in foot pain.
Background: Foot blisters are common and painful nuisances in competitive sports and in military service. The pathogenesis of the problem is related to excessive frictional forces experienced on or under the foot. The incidence of foot blisters in marathon runners can reach 39%. Similarly, up to 42% of cadets in Reserve Officers’ Training Corps camps might be prone to foot blisters. Although the problem usually disappears within 5 days, a single blister might be a major problem in competitive sports or in a wilderness setting. Military training and combat effectiveness might also be compromised by foot blisters. This study sought to reveal the distribution of plantar shear forces in athletic individuals and its relevance to foot blisters.
Methods: Three groups of 11 participants each were studied: blister, adult control, and pediatric control. A custom-built shear and pressure platform was used to collect plantar pressure and shear data while the participants walked over the device. Data were analyzed with repeated-measures analysis of variance.
Results: The blister group had significantly increased pressure and shear stress magnitudes compared with the other groups, although no significant group-site interaction was found. The shear-time integral values were increased approximately 50% at specific sites of the athletic feet, suggesting that contact time may play a role in blister formation.
Conclusions: The biomechanical interaction on the plantar surface of a blister-prone person is different from that of individuals who are less prone to the problem. (J Am Podiatr Med Assoc 100(2): 116–120, 2010)
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.
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.
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.
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.
The purpose of this study was to determine the reliability and validity of two center-of-pressure quantification methods. One hundred five individuals (33 men and 72 women) with a mean age of 26.7 years participated in phase 1 of the study. Two measures of the center-of-pressure pattern, the lateral-medial area index and the lateral-medial force index, were calculated from plantar pressure data collected on all subjects. Between-trial reliability of the two measurements was assessed using intraclass correlation coefficients. In phase 2, frontal plane motion of the rearfoot was recorded in 30 individuals. Pearson correlation coefficients were then calculated between the two center-of-pressure indices and the magnitude of rearfoot eversion obtained from each subject during walking. Intraclass correlation coefficient values ranged from 0.374 to 0.889 for the lateral-medial area index and from 0.215 to 0.905 for the lateral-medial force index. Pearson correlation coefficients between the two center-of-pressure indices and the rearfoot kinematic variables ranged from 0.050 to 0.165. The lateral-medial area index and the lateral-medial force index may have adequate between-trial reliability but are not related to the magnitude of frontal plane rearfoot eversion during the stance phase of walking. (J Am Podiatr Med Assoc 93(2): 142-149, 2003)
Idiopathic toe-walking (ITW) gait may present in children older than 3 years and in the absence of a medical condition known to cause or be associated with toe-walking gait. It is unknown how this gait type changes pressure distribution in the growing foot. We sought to determine whether children with ITW gait exhibit different plantar pressures and temporal gait features than typically developing children.
Children aged 3 to 6 years were recruited who had either a typical heel-toe gait pattern or a diagnosis of ITW. The ITW diagnosis was reported by the parent/caregiver and confirmed through history and physical examination. Temporal gait measures, peak pressures, and impulse percentages were measured. A minimum of ten unshod footprints were collected. Data were compared with unpaired t tests.
The study included 40 children with typical gait and 56 with ITW gait. The ITW group displayed lower peak pressures at the hallux, midfoot, and hindfoot (P < .05) and higher and lower pressure impulse percentages at the forefoot (P < .001) and hindfoot (P < .001), respectively. The ITW group spent a higher percentage of contact time at all areas of the forefoot and less at the midfoot and rearfoot (P < .05). There were no significant differences in total step duration and foot progression angle between groups (P > .05).
There were differences in pressure distributions between groups. Understanding these differences may help us better understand the compensations or potential long-term impact that ITW gait may have on a young child's foot. Podiatric physicians may also consider the use of this equipment in the clinical setting to measure outcomes after treatment for ITW.
Background: We sought to determine whether symptomatic medial knee osteoarthritis is associated with aberrant loading across the foot during gait.
Methods: Twenty-five individuals with medial knee osteoarthritis were compared with 25 controls. Knee radiographs and Western Ontario and McMaster Universities Arthritis Index questionnaires were obtained. Participants walked barefoot over pressure sensors, and the center-of-pressure trace was plotted against the axis of the foot, and a center-of-pressure index was calculated.
Results: The center-of-pressure indices in the medial knee osteoarthritis group demonstrated high lateral loading compared with the central center-of-pressure pattern in controls (P < .001). There was a correlation between the severity of pain and the center-of-pressure index in patients with medial knee osteoarthritis but no correlation between center of pressure and radiographic severity.
Conclusions: The plantar pressure patterns of patients with medial knee osteoarthritis demonstrated greater loading of the lateral aspect of the foot during the contact and midstance phases of gait but not during propulsion compared with those of controls, suggesting that loading patterns in the feet are related to osteoarthritis in the knee. (J Am Podiatr Med Assoc 100(3): 178–184, 2010)
Background: Although pilon fractures are rare, they are important for orthopedic surgeons because of the difficulty of their treatment and their adverse effects on gait function. The aim of this was study to evaluate the relationship between the reduction quality of the fracture, functional results, ankle arthrosis, and plantar pressure distribution in patients with tibia pilon fractures.
Methods: In this study, a total of 62 patients treated for an intraarticular pilon fracture in our clinic between January of 2015 and January of 2019 were evaluated retrospectively. Postoperative reduction qualities of the patients were evaluated with the Ovadia-Beals criteria; ankle functional scores were evaluated with the Teeny-Wiss score; and ankle arthrosis was evaluated with the Takakura classification. At the last patient follow-up, foot loading analysis was performed, and the results were evaluated for their relation with postoperative reduction quality, ankle function, and ankle arthrosis.
Results: There were 62 patients (50 men and 12 women). The average age was 43.3 years (range, 19–78 years). The mean follow-up was 34.3 months (range, 24–58 months). The mean Ovadia-Beals score was 12.35 ± 4.6 on the postoperative plain radiographs of the patients; the mean Teeny-Wiss score at the last follow-up was 76.82 ± 17.69; and the mean Takakura score was 1.47 ± 1.35. Based on the pedobarographic measurements, 47.58% of the patients put weight on the anterior portion and 52.42% on the posterior portion of the foot in the anteroposterior plane. In the mediolateral plane, 42.15% loaded on the medial portion of the ankle and 57.85% loaded on the lateral portion of the foot.
Conclusions: Intra-articular tibia pilon fractures can be demonstrated by lateralization of the walking axis and changes in gait patterns and can be associated with clinical outcome.
Proximal diaphyseal stress fractures of the fifth metatarsal are common in athletes. Conservative treatment has been shown to result in high rates of delayed union, nonunion, and refracture, so internal fixation has become the treatment of choice in competitive athletes.
Twenty top-level athletes with diaphyseal stress fractures fixed with intramedullary malleolar screws were evaluated. Functional outcome was assessed by American Orthopaedic Foot and Ankle Society midfoot score. Static and dynamic maximum vertical force and peak plantar pressures were evaluated with a computerized pedobarograph.
Mean follow-up from surgery to interview was 10.3 years (range, 3.5–19.0 years). Clinical healing was 95%, and there has been one refracture (5%). The mean time from surgery to return to sport was 9 weeks (range, 5–14 weeks). Twelve athletes (60%) returned to a higher level of training, 7 (35%) to the same level, and 1 (5%) to a lower level compared with the level of training before injury. Average American Orthopaedic Foot and Ankle Society midfoot score was 93.8 (range, 85–100). During the computerized pedobarographic evaluations, 18 patients (90%) presented with varus of the metatarsus and the midfoot and 2 (10%) presented with a normal plantigrade foot.
Intramedullary malleolar screws can yield reliable and effective healing of fifth metatarsal stress fractures in athletes. Varus of the metatarsus and the midfoot were predisposing factors for stress fractures in this population of competitive athletes, and all were recommended to wear orthoses until their competitive careers were completed. (J Am Podiatr Med Assoc 101(6): 517–522, 2011)
Background: Foot orthoses have been described as a possible intervention for individuals with patellofemoral joint pain. No study has attempted to quantify the perceived comfort and support of foot orthoses when used as an intervention for patellofemoral joint pain.
Methods: A randomized case-control trial with crossover between contoured and flat orthoses was conducted on ten individuals with patellofemoral pain and ten healthy participants. All of the participants completed a comfort-support assessment and had in-shoe plantar pressure data collected before and after 3 weeks of wear. A 1-week washout period was used to minimize any continued treatment effect between orthotics testing. The patellofemoral pain group also completed a numeric rating scale to assess pain reduction after using each orthosis.
Results: All of the participants perceived that greater support was provided by the contoured orthoses in the heel and arch regions. Even with a 30% difference in material hardness between the two orthoses, all of the participants rated cushioning as equivalent. Six individuals in the patellofemoral pain group reported a clinically significant reduction in knee pain as a result of wearing foot orthoses.
Conclusions: A key factor in the selection of contoured foot orthoses versus flat inserts is the amount of support that an individual perceives in the arch and heel regions. In addition, clinicians using foot orthoses as an intervention for patellofemoral pain should expect an individualistic, nonsystematic response. (J Am Podiatr Med Assoc 101(1): 7–16, 2011)
The mechanical effects of genu valgum and varum deformities on the subtalar joint were investigated. First, a theoretical model of the forces within the foot and lower extremity during relaxed bipedal stance was developed predicting the rotational effect on the subtalar joint due to genu valgum and varum deformities. Second, a kinetic gait study was performed involving 15 subjects who walked with simulated genu valgum and genu varum over a force plate and a plantar pressure mat to determine the changes in the ground reaction force vector within the frontal plane and the changes in the center-of-pressure location on the plantar foot. These results predicted that a genu varum deformity would tend to cause a subtalar pronation moment to increase or a supination moment to decrease during the contact and propulsion phases of walking. With genu valgum, it was determined that during the contact phase a subtalar pronation moment would increase, whereas in the early propulsive phase, a subtalar supination moment would increase or a pronation moment would decrease. However, the current inability to track the spatial position of the subtalar joint axis makes it difficult to determine the absolute direction and magnitudes of the subtalar joint moments. (J Am Podiatr Med Assoc 95(6): 531–541, 2005)