Custom Therapeutic Insoles Based on Both Foot Shape and Plantar Pressure Measurement Provide Enhanced Pressure Relief

Abstract

OBJECTIVE -The purpose of this study was to determine whether custom insoles tailored to contours of the barefoot pressure distribution and shape of a patient's foot can reduce plantar pressures in the metatarsal head (MTH) region to a greater extent than conventional custom insoles.RESEARCH DESIGN AND METHODS -Seventy regions of elevated barefoot pressures (mean peak 834 kPa under MTHs) were identified in 20 subjects with diabetes. Foam box impressions of their feet were sent to three different orthotic supply companies for fabrication of custom insoles. One company was also given plantar pressure data, which were incorporated into the insole design. Measurements of in-shoe plantar pressures were recorded during gait for the three custom insoles in a flexible and a rocker-bottom shoe. Peak pressure and force-time integral were extracted for analysis.RESULTS -In 64 of 70 regions, the shape-plus-pressure-based insole in the flexible shoe achieved superior unloading compared with the two shape-based insoles. On average, peak pressure was reduced by 32 and 21% (both P Յ 0.0001) and force-time integral by 40 and 34% (both P Ͻ 0.0001) compared with the shape-based insoles. At the midfoot, force-time integral was increased by 51 and 33% (both P Ͻ 0.01). Similar trends were found using the rockerbottom shoe.CONCLUSIONS -Compared with insoles based only on shape, the use of foot shape with barefoot plantar pressure measurements in designing custom insoles results in enhanced offloading of high-pressure areas under the forefoot. This offloading was achieved by a greater transfer of load to the midfoot without additional loading of other forefoot structures.

Manufacturing and finite element assessment of a novel pressure reducing insole for Diabetic Neuropathic patients

“…They found that a custom insole that its shape is coincident with plantar curvature reduces the plantar pressure more effectively [19]. Lavery et al 2005 investigated the shear stress parameter in three-layer insole that was made by plastazote foam (PLZ), Prone and EVA by using experimental testing.…”

Controversies in off-loading: Should big brother be watching?

“…The TCC is commonly recognized as the "gold standard" in healing ulcers. Although some RCWs were demonstrated in the gait laboratory to be as effective as the TCC in off-loading the foot [7][8][9], a clinical trial by Armstrong et al [10] found that the TCC resulted in higher healing rates and a shorter time to healing than an RCW with a similar capacity for off-loading wounds. It was hypothesized that the TCC's ability to ensure compliance was responsible for the difference in healing.…”

“…Prefabricated inlays and shoes are routinely prescribed to high-risk patients. Numerous studies have demonstrated these to be highly efficacious in off-loading the foot [9,13,14]. Some preliminary studies have shown prescribed footwear to be effective in preventing ulcer reoccurrence [12].…”

A daily physical activity and diet intervention for individuals with type 2 diabetes mellitus: a randomized controlled trial

“…The examination included vascular, neurological, dermatological and orthopedic assessments. Therapeutic insoles based on the shape and plantar pressure management and the type of shoe the subject wore were supplied to the participants if necessary (Owings et al 2008). It was hoped that this inter vention would contribute to improved compliance to the walk program and comfort of the participants.…”