A comparison of trial shoe and shell shoe fitting techniques

A study of in-shoe plantar shear in normals

OBJECTIVE

To quantify features of in-shoe plantar shear in asymptomatic adult gait.

DESIGN

In order to standardize footwear conditions and facilitate later comparison to patient groups, measurement is made in a group of adults walking freely in stock orthopaedic footwear.

BACKGROUND

Better data on plantar shear is required to complement well-documented pressure data for an overall picture of plantar stress.

METHODS

Measurements were made locally beneath the medial four metatarsal heads and heel using biaxial transducers mounted flush into an inlay. Pressure distribution was also measured.

RESULTS

The shear data revealed common features in the shear pattern occurring at defined phases of gait, with good inter-step reliability. For the five sites of interest, these values ranged from 24 kPa to 70.4 kPa, and 31 kPa to 86.5 kPa for individuals wearing nylon hose or hose-free respectively. Maximum shear occurred more laterally than maximum pressure.

CONCLUSIONS

Features of plantar shear were not always as expected; for example the forward thrust at push-off was not reflected in the anteroposterior shear stress. Because of the inter-subject variability, study of a larger group is indicated.

RELEVANCE

Mechanical stress at the plantar interface between foot and shoe is of particular clinical relevance to the formation and management of ulcers in diabetic neuropathy. It is also of relevance to shoe and orthotic design for various foot pathologies. This study provides reliable data on the shear component of plantar stress for which, unlike the well-documented pressure component, there is only sparse data so far available.

Patient compliance and effect of orthopaedic shoes

Orthopaedic shoes are individually handmade after a prescription from an orthopaedic surgeon, hence relatively expensive. Bad compliance is mentioned in the literature but not investigated. In order to evaluate patient compliance and the effect of orthopaedic shoes, 85 patients who were prescribed orthopaedic shoes at the authors' department during a 3 year period received a questionnaire concerning relief of symptoms and daily use of the shoes. The answers from 74 patients were correlated to the prescription procedure and the degree of medical follow-up. Only 60 of 74 patients used their shoes. Some 51 patients had some benefit while 23 had no effect or even worse symptoms. Some patients even used their shoes despite no symptomatic relief. However, patients who felt they were well informed about the purpose and function of their shoes had more benefit than the rest. Only 12 patients of the 74 were checked by the orthopaedic surgeon after delivery of the shoes. In conclusion the authors believe there is a great need for information to be given to the patients about the functions and limitations of orthopaedic shoes and that every patient should be offered a control check-up by the surgeon. Further investigations of the effect of orthopaedic shoes should be carried out to optimise the use of these expensive devices.