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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.
Background
Although numerous studies suggest the benefit of electrical stimulation (E-Stim) therapy to accelerate wound healing, the underlying mechanism of action is still debated. In this pilot study, we examined the potential effectiveness of lower-extremity E-Stim therapy to improve tissue perfusion in patients with diabetic foot ulcers.
Methods
Thirty-eight patients with diabetic foot ulcers underwent 60 min of active E-Stim therapy on acupuncture points above the level of the ankle joint using a bioelectric stimulation technology platform. Perfusion changes in response to E-Stim were assessed by measuring skin perfusion pressure (SPP) at baseline and during 30 and 60 min of therapy; retention was assessed 10 min after therapy. Tissue oxygen saturation (SatO2) was measured using a noninvasive near-infrared camera.
Results
Skin perfusion pressure increased in response to E-Stim therapy (P = .02), with maximum improvement observed at 60 min (11%; P = .007) compared with baseline; SPP reduced 10 min after therapy but remained higher than baseline (9%; P = .1). Magnitude of improvement at 60 min was negatively correlated with baseline SPP values (r = –0.45; P = .01), suggesting that those with lower perfusion could benefit more from E-Stim therapy. Similar trends were observed for SatO2, with statistically significant improvement for a subsample (n = 16) with moderate-to-severe peripheral artery disease.
Conclusions
This study provides early results on the feasibility and effectiveness of E-Stim therapy to improve skin perfusion and SatO2. The magnitude of benefit is higher in those with poorer skin perfusion. Also, the effects of E-Stim could be washed out after stopping therapy, and regular daily application might be required for effective benefit in wound healing.
Background:
We explored gait differences in patients with diabetes and peripheral neuropathy (DPN) and aged-matched controls over short and long walking distances. The potential benefit of footwear for improving gait in patients with DPN was also explored.
Methods:
Twelve patients with DPN and eight controls walked at their habitual speed over short (7 m) and long (20 m) distances under two conditions: barefoot and regular shoes. A validated system of body-worn sensors was used to extract spatiotemporal gait parameters. Neuropathy severity was quantified using vibratory perception threshold measured at the great toe.
Results:
Gait deterioration in the DPN group was observed during all of the walking trials. However, the difference between patients with DPN and participants in the control group achieved statistical significance only during long walking distance trials. Shod and barefoot double support times were longer in the DPN group during long walking distances (>20%, P = .03). Gait unsteadiness, defined as coefficient of variation of gait velocity, was also significantly higher in the DPN group when barefoot walking over long distances (83%, P = .008). Furthermore, there was a high correlation between neuropathy severity and gait unsteadiness best demonstrated during the barefoot walking/long walking distance condition (r = 0.77, P < .001). The addition of footwear improved gait steadiness in the DPN group by 46% (P = .02). All differences were independent of age, sex, and body mass index (P > .05).
Conclusions:
This study suggests that gait alteration in patients with DPN is most pronounced while walking barefoot over longer distances and that footwear may improve gait steadiness in patients with DPN. (J Am Podiatr Med Assoc 103(3): 165–173, 2013)
Background: While numerous studies suggest the benefit of electrical stimulation (E-Stim) therapy to accelerate wound healing, the underlying mechanism of action is still debated. In this pilot study, we examined the potential effectiveness of lower extremity E-Stim therapy to improve tissue perfusion in patients with diabetic foot ulcers (DFUs). Methods: Thirty-eight patients with DFUs were recruited. Participants underwent 60-minutes of active E-Stim therapy provided on acupuncture points above the level of the ankle joint using a bio-electric stimulation technology® (BEST) platform (Tennant Biomodulator® PRO). As primary outcome, changes in perfusion in response to E-Stim were assessed by measuring skin perfusion pressure (SPP) at baseline, 30-, and 60-min during therapy. In addition, retention was assessed 10-min post-therapy. As secondary outcome, tissue oxygen saturation (SatO2) was measured using a non-invasive near-infrared camera (Snapshot NIR, KENT Imaging Inc). Results: SPP increased in response to E-Stim therapy (p = 0.02) with maximum improvement observed at 60-min (11%, p = 0.007) compared to baseline. SPP reduced at 10-min post therapy, but remained higher than baseline (9%, p = 0.1). Magnitude of improvement at 60-min was negatively correlated with baseline SPP values (r = -0.45, p = 0.01) suggesting those with lower perfusion could benefit more from E-Stim therapy. Similar trends were observed for SatO2 with statistically significant improvement for a sub-sample (n=16) with moderate-severe peripheral arterial disease (Ankle brachial index < 0.8 or > 1.4). Conclusions: This study provides early results on the feasibility and effectiveness of E-Stim therapy to improve skin perfusion and SatO2. The magnitude of benefit is higher among those with poorer skin perfusion. Results also suggest the effects of E-Stim could be washed out after stopping therapy and thus regular daily application may be required for the effective benefit for wound healing.
Background: This pilot study examined the effect of custom and prefabricated foot orthoses on self-selected walking speed, walking speed variability, and dynamic balance in the mediolateral direction.
Methods: The gait of four healthy participants was analyzed with a body-worn sensor system across a distance of at least 30 m outside of the gait laboratory. Participants walked at their habitual speed in four conditions: barefoot, regular shoes, prefabricated foot orthoses, and custom foot orthoses.
Results: In the custom foot orthoses condition, gait speed was improved on average 13.5% over the barefoot condition and 9.8% over the regular shoe condition. The mediolateral range of motion of center of mass was reduced 55% and 56% compared with the shoes alone and prefabricated foot orthoses conditions, respectively. This may suggest better gait efficiency and lower energy cost with custom foot orthoses. This tendency remained after normalizing center of mass by gait speed, suggesting that irrespective of gait speed, custom foot orthoses improve center of mass motion in the mediolateral direction compared with other footwear conditions. Gait intercycle variability, measured by intercycle coefficient of variation of gait speed, was decreased on average by 25% and 19% compared with the barefoot and shoes-alone conditions, respectively. The decrease in gait unsteadiness after wearing custom foot orthoses may suggest improved proprioception from the increased contact area of custom foot orthoses versus the barefoot condition.
Conclusions: These findings may open new avenues for objective assessment of the impact of prescribed footwear on dynamic balance and spatiotemporal parameters of gait and assess gait adaptation after use of custom foot orthoses. (J Am Podiatr Med Assoc 100(4): 242–250, 2010)
Background
Up to 10% of people will experience heel pain. The purpose of this prospective, double-blind, randomized clinical trial was to compare custom foot orthoses (CFO), prefabricated foot orthoses (PFO), and sham insole treatment for plantar fasciitis.
Methods
Seventy-seven patients with plantar fasciitis for less than 1 year were included. Outcome measures included first step and end of day pain, Revised Foot Function Index short form (FFI-R), 36-Item Short Form Health Survey (SF-36), activity monitoring, balance, and gait analysis.
Results
The CFO group had significantly improved total FFI-R scores (77.4 versus 57.2; P = .03) without group differences for FFI-R pain, SF-36, and morning or evening pain. The PFO and CFO groups reported significantly lower morning and evening pain. For activity, the CFO group demonstrated significantly longer episodes of walking over the sham (P = .019) and PFO (P = .03) groups, with a 125% increase for CFOs, 22% PFOs, and 0.2% sham. Postural transition duration (P = .02) and balance (P = .05) improved for the CFO group. There were no gait differences. The CFO group reported significantly less stretching and ice use at 3 months.
Conclusions
The CFO group demonstrated 5.6-fold greater improvements in spontaneous physical activity versus the PFO and sham groups. All three groups improved in morning pain after treatment that included standardized athletic shoes, stretching, and ice. The CFO changes may have been moderated by decreased stretching and ice use after 3 months. These findings suggest that more objective measures, such as spontaneous physical activity improvement, may be more sensitive and specific for detecting improved weightbearing function than traditional clinical outcome measures, such as pain and disease-specific quality of life.
The Role of Podiatry in the Prevention of Falls in Older People
A JAPMA Special Issue
Given the age-related decline in foot strength and flexibility, and the emerging evidence that foot problems increase the risk of falls, established guidelines for falls prevention recommend that older adults have their feet examined by a podiatrist as a precautionary measure. However, these guidelines do not specify which intervention activities might be performed. Published in this special issue of JAPMA are nine high-quality articles, including seven original studies and two basic science reviews, focusing on the benefit and impact of footwear and foot and ankle interventions in reducing the risk of falling. The selected studies discuss various relevant questions related to podiatric intervention, including adherence to intervention; preference and perception of older adults in selecting footwear; benefit of insoles, footwear, and nonslip socks in preventing falls; fear of falling related to foot problems; benefit of podiatric surgical intervention; and benefit of foot and ankle exercise in preventing falls. (J Am Podiatr Med Assoc 103(6): 452–456, 2013)
Background:
Patients with diabetic peripheral neuropathy (DPN) demonstrate gait alterations compared with their nonneuropathic counterparts, which may place them at increased risk for falling. However, it is uncertain whether patients with DPN also have a greater fear of falling.
Methods:
A voluntary group of older adults with diabetes was asked to complete a validated fear of falling questionnaire (Falls Efficacy Scale International [FES-I]) and instructed to walk 20 m in their habitual shoes at their habitual speed. Spatiotemporal parameters of gait (eg, stride velocity and gait speed variability) were collected using a validated body-worn sensor technology. Balance during walking was also assessed using sacral motion in the mediolateral and anteroposterior directions. The level of DPN was quantified using vibration perception threshold from the great toe.
Results:
Thirty-four diabetic patients (mean ± SD: age, 67.6 ± 9.2 years; body mass index, 30.9 ± 5.7; hemoglobin A1c, 7.9% ± 2.3%) with varying levels of neuropathy (mean ± SD vibration perception threshold, 34.6 ± 22.9 V) were recruited. Most participants (28 of 34, 82%) demonstrated moderate to high concern about falling based on their FES-I score. Age (r = 0.6), hemoglobin A1c level (r = 0.39), number of steps required to reach steady-state walking (ie, gait initiation) (r = 0.4), and duration of double support (r = 0.44) were each positively correlated with neuropathy severity (P < .05). Participants with a greater fear of falling also walked with slower stride velocities and shorter stride lengths (r = −0.3 for both, P < .05). However, no correlation was observed between level of DPN and the participant’s actual concern about falling.
Conclusions:
Fear of falling is prevalent in older adults with diabetes mellitus but is unrelated to level of neuropathy. (J Am Podiatr Med Assoc 103(6): 480–488, 2013)
Hallux Valgus Surgery May Produce Early Improvements in Balance Control
Results of a Cross-Sectional Pilot Study
Background:
Hallux valgus (HV) is associated with poorer performance during gait and balance tasks and is an independent risk factor for falls in older adults. We sought to assess whether corrective HV surgery improves gait and balance.
Methods:
Using a cross-sectional study design, gait and static balance data were obtained from 40 adults: 19 patients with HV only (preoperative group), 10 patients who recently underwent successful HV surgery (postoperative group), and 11 control participants. Assessments were made in the clinic using body-worn sensors.
Results:
Patients in the preoperative group generally demonstrated poorer static balance control compared with the other two groups. Despite similar age and body mass index, postoperative patients exhibited 29% and 63% less center of mass sway than preoperative patients during double-and single-support balance assessments, respectively (analysis of variance P =.17 and P =.14, respectively [both eyes open condition]). Overall, gait performance was similar among the groups, except for speed during gait initiation, where lower speeds were encountered in the postoperative group compared with the preoperative group (Scheffe P = .049).
Conclusions:
This study provides supportive evidence regarding the benefits of corrective lower-extremity surgery on certain aspects of balance control. Patients seem to demonstrate early improvements in static balance after corrective HV surgery, whereas gait improvements may require a longer recovery time. Further research using a longitudinal study design and a larger sample size capable of assessing the long-term effects of HV surgical correction on balance and gait is probably warranted. (J Am Podiatr Med Assoc 103(6): 489–497, 2013)
Balance Rehabilitation
Promoting the Role of Virtual Reality in Patients with Diabetic Peripheral Neuropathy
Background:
Individuals with diabetic peripheral neuropathy frequently experience concomitant impaired proprioception and postural instability. Conventional exercise training has been demonstrated to be effective in improving balance but does not incorporate visual feedback targeting joint perception, which is an integral mechanism that helps compensate for impaired proprioception in diabetic peripheral neuropathy.
Methods:
This prospective cohort study recruited 29 participants (mean ± SD: age, 57 ± 10 years; body mass index [calculated as weight in kilograms divided by height in meters squared], 26.9 ± 3.1). Participants satisfying the inclusion criteria performed predefined ankle exercises through reaching tasks, with visual feedback from the ankle joint projected on a screen. Ankle motion in the mediolateral and anteroposterior directions was captured using wearable sensors attached to the participant’s shank. Improvements in postural stability were quantified by measuring center of mass sway area and the reciprocal compensatory index before and after training using validated body-worn sensor technology.
Results:
Findings revealed a significant reduction in center of mass sway after training (mean, 22%; P = .02). A higher postural stability deficit (high body sway) at baseline was associated with higher training gains in postural balance (reduction in center of mass sway) (r = −0.52, P < .05). In addition, significant improvement was observed in postural coordination between the ankle and hip joints (mean, 10.4%; P = .04).
Conclusions:
The present research implemented a novel balance rehabilitation strategy based on virtual reality technology. The method included wearable sensors and an interactive user interface for real-time visual feedback based on ankle joint motion, similar to a video gaming environment, for compensating impaired joint proprioception. These findings support that visual feedback generated from the ankle joint coupled with motor learning may be effective in improving postural stability in patients with diabetic peripheral neuropathy. (J Am Podiatr Med Assoc 103(6): 498–507, 2013)
