Efficacy of multilayered hosiery in reducing in-shoe plantar foot pressure in high-risk patients with diabetes.
ABSTRACT High plantar pressure is an acknowledged risk factor in the development of plantar ulcers in the diabetic neuropathic foot. This study examines the ability of preventive foot care (PFC) socks to reduce plantar foot pressures in a sample of high-risk patients with diabetes.
Nineteen patients with established peripheral neuropathy attending a complications clinic of the Manchester Diabetes Centre were recruited to the study. Fifteen (78%) of the patients were male, 40-80 years of age, and ulcer-free at the time of recruitment. In-shoe plantar pressure measurements were recorded using the F-Scan and compared PFC socks with ordinary supermarket socks. The analysis measured differences in maximum foot contact area and plantar pressure for the whole foot, forefoot, and peak plantar pressure areas.
The results showed a significant increase in maximum foot contact area of 11 cm2 (95% CI 7-11) when subjects wore the PFC socks (P < 0.01). This was accompanied by 5.4 kPa (3.5-7.3) or 9% reduction in total foot pressure (P < 0.01). Similar results were observed at the forefoot, which showed a 14.2% increase in contact area and a 10.2% reduction in peak forefoot pressure.
These results suggest that the wearing of PFC socks increases the underfoot contact area and hence decreases plantar foot pressures. Further studies are required to determine whether the pressure and friction reductions achieved by this simple intervention would be effective in reducing the incidence of foot ulcers in high-risk patients.
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ABSTRACT: One of the aims of the sock/shoe unit is to reduce the severity of impact forces on the lower extremity although the injury prevention potential of the sock through the attenuation of impact force has yet to be established. This study aims to determine the effect of athletic socks and a sock/shoe unit on peak impact force, time to peak impact force and loading rate using an impact testing methodology. An impact testing system with a gravity driven vertical impact striker (8.5kg) fitted with a load cell (10,000Hz) which was released from 0.05m to impact the specimen on the vertical axis (impact velocity=0.99m·s(-1)) was used throughout the study. All socks reduced peak impact force by between 6% and 20% when compared to a no sock control condition. Furthermore, large significant correlation coefficients (r=.62 to .72) were observed between thickness and peak impact force, time to peak impact force and loading rate in the sock only condition. Athletic socks demonstrate cushioning properties under impact testing conditions.Clinical biomechanics (Bristol, Avon) 07/2013; · 1.76 Impact Factor
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ABSTRACT: In this paper, in-shoe blister formation during running is analyzed and possibilities to reduce these cutaneous lesions by appropriate sock properties are discussed. Six types of cotton-made athletic socks were studied in order to evaluate the influence of the knitted structure on the sock-to-skin friction (terry jersey, plain jersey, and non-raised jersey duffel structures). The contact conditions between a running shoe and foot areas prone to friction blisters were simulated using a linear reciprocating tribometer, and the friction behavior of the socks in contact with a mechanical skin model was investigated. In additional experiments, the shock absorption properties of the socks were measured. Among the investigated socks, the terry jersey fabric knitted in a specific process and a dense, tight jersey structure, i.e. a plain jersey knitted with two yarns, were found to be most suitable for running socks.Textile Research Journal 05/2013; 83(8):836-848. · 1.14 Impact Factor
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ABSTRACT: Dynamic in-shoe plantar pressure assessment is used both in research and clinical practice to evaluate therapeutic footwear interventions in neuropathic diabetic patients. The aim was to determine the required number of footsteps for reliable and valid in-shoe plantar pressure data in these patients. In 30 neuropathic diabetic patients wearing custom-made therapeutic footwear, in-shoe plantar pressures were measured for a minimum of 20 midgait walking steps per foot. For each incremental number of steps and for each of six anatomical regions per foot, peak pressure, pressure-time integral, contact area, contact time, and force-time integral were calculated. Reliability was assessed by calculating intraclass correlation coefficients. Validity was assessed by calculating the coefficient of variation between each n-step protocol and the 20-step reference protocol based on Limits of Agreement analysis. Data was considered reliable with intraclass correlation coefficients >0.90 and valid with coefficients of variation <10%. Three steps per foot were required to obtain reliable data for each foot region and parameter. Depending on the parameter, between 7 and 17 steps per foot were required to obtain valid data. With the exception of deviant outcomes in three forefoot regions for force-time integral, overall 12 steps per foot were required for valid data. For neuropathic diabetic patients wearing custom-made therapeutic footwear, 12 midgait steps per foot are required to obtain valid and reliable in-shoe plantar pressure data. This provides directions for the use of in-shoe plantar pressure analysis in research and clinical practice in this patient group.Clinical biomechanics (Bristol, Avon) 06/2011; 26(8):880-4. · 1.76 Impact Factor