Steven A. Vela

Reducing Dynamic Foot Pressures in High-Risk Diabetic Subjects With Foot Ulcerations: A comparison of treatments

OBJECTIVE To compare the effectiveness of total contact casts, commercially available therapeutic shoes, and removable walking casts to reduce mean peak plantar foot pressures at the site of neuropathic ulcerations in diabetic subjects. RESEARCH DESIGN AND METHODS We compared the reduction in peak plantar pressures at ulcer sites under the great toe (n = 5), first metatarsal (n = 10), and second through fifth metatarsals (n = 10) using six treatments: total contact casts (TCCs), DH Pressure Relief Walkers (DH), Aircast Pneumatic Walkers, Three D Dura-Steppers (3D), CAM Walkers, and P.W. Minor Xtra Depth shoes. A rubber sole canvas oxford was used to establish baseline pressure values. The canvas oxford could be viewed as a worse-case scenario for this patient population. With the EMED Pedar in-shoe pressure measurement system, data for 40 steps were collected for each treatment. We used Tukeys Studentized Range Test for simultaneous multiple comparisons to compare treatments. RESULTS DH Pressure Relief Walkers reduced plantar pressures significantly better than other commercially available treatments for ulcers under the first metatarsal, second through fifth metatarsals, and great toe (P < 0.05). There was not a significant difference in mean peak plantar pressures between TCCs and DHs at any of the forefoot ulcer sites. CONCLUSIONS DH Pressure Relief Walkers were as effective as total contact casts to reduce foot pressures at ulcer sites and may be an effective practical addition in the treatment of foot ulcers.

Reducing Plantar Pressure in the Neuropathic Foot: A comparison of footwear

OBJECTIVE To compare the effectiveness of therapeutic, comfort, and athletic shoes with and without viscoelastic insoles. RESEARCH DESIGN AND METHODS We compared pressure reduction at ulcer sites under the hallux (n = 10), first metatarsal (n = 10), and lesser metatarsals (n = 12), using extra-depth, athletic, and comfort shoes with and without viscoelastic insoles. A rubber-soled canvas oxford was used to establish baseline pressure values. RESULTS When used in conjunction with a viscoelastic insole, all shoe types reduced mean peak plantar pressure better than their non-insoled counterparts (P < 0.05). Consistently, comfort shoes reduced pressure significantly better than both the cross trainers and extra-depth shoes for ulcers under the first and lesser metatarsals (P < 0.05). For each shoe type, the addition of the viscoelastic insole provided a significant reduction in mean peak pressure (P < 0.05). Compared with stock insoles, viscoelastic insoles reduced pressures an additional 5.4-20.1% at ulcer sites. The same trend was also observed at regions of the foot not associated with an ulceration. CONCLUSIONS When used in conjunction with a viscoelastic insole, both the comfort and athletic cross-trainer shoes studied were as, if not more, effective than commonly prescribed therapeutic shoes in reducing mean peak first and lesser metatarsal pressures. Furthermore, comfort shoes were as effective as therapeutic shoes in reducing pressure under the great toe. Both of these shoe types may be viable options to prevent the development or recurrence of foot ulcers.

The effect of increased weight on peak pressures: Implications for obesity and diabetic foot pathology

The purpose of this study was to determine if increased weight contributes to increased mean peak plantar foot pressures when foot function, deformity, and structure are controlled. Ten male and nine female volunteers without sensory neuropathy or other systemic disease were evaluated in the study. Using a repeated measures design, peak plantar foot pressures were compared using the Novel Pedar in-shoe pressure measurement system under three conditions. Baseline measurements were made while volunteers wore the standard test footwear, a thin-soled rubber oxford sneaker. The second and third test conditions involved pressure measurements with an additional 9.1 kg (20 lb) and 18.2 kg (40 lb), respectively, of weight evenly distributed in pockets on the front and back of a workout vest. There was a significant increase in mean peak plantar foot pressures under the metatarsal heads, heel, and midfoot for each incremental increase of weight (baseline vs. 9.1 kg, p < .05; 9.1 kg vs. 18.2 kg, p < .05). The authors conclude that increases in weight increased plantar foot pressures for the first metatarsal, lesser metatarsal, midfoot, and heel regions in both men and women.

Total contact casts: Pressure reduction at ulcer sites and the effect on the contralateral foot

OBJECTIVE To compare the effectiveness of total contact casts with a cast boot (TCCB), total contact casts with a cast heel (TCCH), and therapeutic XtraDepth shoes (XDS) to reduce ulcer site pressures and to determine if total contact casts increase contralateral pressures. DESIGN Repeat measure design with 40 replications nested within each treatment for each patient. METHODS Peak contralateral foot pressures and ulcer site pressures under the 1st metatarsal (1MET; n = 10), 2nd to 5th metatarsals (2-5MET; n = 10), and great toe (GT; n = 5) were compared using the Novel-Pedar system and three treatments: TCCB, TCCH, and XDS. Baseline pressures were established using canvas oxfords. RESULTS There was no difference in pressure reduction with TCCH vs. TCCB for 1MET or GT ulcers, but TCCH reduced pressure better for 2-5MET ulcers (p < .001). Contralateral pressures were not elevated in either TCC group. CONCLUSIONS TCCH were superior to TCCB in reducing 2-5MET ulcer pressures and equivalent to TCCB for 1MET and GT ulcers. Contralateral pressures are not increased by TCC use.

NOVEL METHODOLOGY TO OBTAIN SALIENT BIOMECHANICAL CHARACTERISTICS OF INSOLE MATERIALS

Viscoelastic inserts are commonly used as artificial shock absorbers to prevent neuropathic foot ulcerations by decreasing pressure on the sole of the foot. Unfortunately, there is little scientific information available to guide physicians in the selection of appropriate insole materials. Therefore, a novel methodology was developed to form a rational platform for biomechanical characterizations of insole material durability, which consisted of in vivo gait analysis and in vitro bioengineering measurements. Results show significant differences in the compressive stiffness of the tested insoles and the rate of change over time in both compressive stiffness and peak pressures measured. Good correlations were found between pressure-time integral and Youngs modulus (r2 = 0.93), and total energy applied and Youngs modulus (r2 = 0.87).

A Novel Methodology To Obtain Salient Biomechanical Characteristics Of Insole Materials

Viscoelastic inserts are commonly used as artificial shock absorbers to prevent neuropathic foot ulcerations by decreasing pressure on the sole of the foot. Unfortunately, there is little scientific information available to guide physicians in the selection of appropriate insole materials. Therefore, a novel methodology was developed to form a rational platform for biomechanical characterizations of insole material durability, which consisted of in vivo gait analysis and in vitro bioengineering measurements. Results show significant differences in the compressive stiffness of the tested insoles and the rate of change over time in both compressive stiffness and peak pressures measured. Good correlations were found between pressure-time integral and Youngs modulus (r2 = 0.93), and total energy applied and Youngs modulus (r2 = 0.87).