Biomechanical issues are now widely recognized as being important in the treatment of diabetic foot disease. The purpose of the present review is to identify advances that have occurred since the previous International Conference on the Diabetic Foot in 1995 in the understanding of foot biomechanics in relation to diabetes. Attention continues to be focused on the identification of a threshold plantar pressure that leads to tissue damage. Recent studies have suggested that peak barefoot pressure may be only 65% specific for the development of ulceration. The association between foot deformity and plantar pressure has been the subject of several quantitative studies, but new questions have been raised about the etiology of claw toes. The measurement of shear stress continues to be an elusive goal although several small studies have presented possibly feasible technical approaches. The importance of callus as a precursor to ulceration has been confirmed experimentally and quantitative measures of motor neuropathy have been presented. Although a number of new devices have been introduced as alternatives to the Total Contact Cast, few clinical studies of their efficacy are available yet. New information on the properties of insole materials has been published including data on changes with repeated cycling. Complications of prophylactic surgery have been shown to include a high rate of Charcot fractures. Two new series describing the fixation of such fractures have also been reported. Biomechanical issues have also been addressed in two sets of guidelines for treatment that have recently been published. These many studies confirm the central role of mechanical stress and its relief in the treatment of neuropathic foot problems in diabetes.

Biomechanical Phenomena↗

PubMedDate not supplied

Decomposition of superimposed ground reaction forces into left and right force profiles.

The process of collecting ground reaction force data by mounting a forceplate beneath a treadmill belt has the advantage that numerous walking trials can be analyzed without the problem of subjects 'targeting' their footsteps. However, a potential problem is that the measured forces represent a summation of bilateral force profiles during the double support phase of walking. To address this issue, an algorithm is described for decomposing superimposed ground reaction force data into individual left and right profiles. It is based on an examination of the side-to-side oscillations of the measured center of pressure (CoP). Whenever the measured CoP exceeds a certain threshold, it is assumed that the person is being supported by a single limb, and the measured GRF data reflect the forces under that limb. Conversely, when the measured CoP indicates that both feet are on the treadmill, it is assumed that the location of the individual CoP under each foot is given by wL2 and wR2. These quantities reflect the greatest excursion of the measured CoP towards the left and right sides of the forceplate, respectively. With this assumption, individual GRF profiles can be calculated by means of solving two simultaneous equations--one describing the equilibrium of forces in the vertical direction, and one describing the equilibrium of moments about an antero-posterior axis of the forceplate. The algorithm describing this procedure is simple enough to be implemented on a spreadsheet and yields estimates for average force, impulse, peak force and stance time that are typically within 3% of the true values.

Adult↗

PubMedDate not supplied

Gait analysis in rehabilitation medicine: a brief report.

Gait analysis can be a powerful tool for rehabilitation research and clinical practice. However, there has been little coordinated effort to set goals for the application of gait analysis in rehabilitation. Therefore, a priority setting process was engaged to obtain the opinions of a diverse pool of experts related to human motion analysis. The primary goal of this process was to develop priorities for future research, development, and standardization in gait analysis. A multistep approach was used that included expert testimony, group discussions, individually developed priorities, and a ranking process. Several important priorities emerged from this activity. The highest priority was assigned to research on the efficacy, outcomes, and cost-effectiveness of gait analysis.

Cost-Benefit Analysis↗

PubMedDate not supplied

The effect of callus removal on dynamic plantar foot pressures in diabetic patients.

Clinical observation suggests that neuropathic foot ulceration frequently occurs beneath plantar callosities and in areas of high dynamic shear and vertical stress underneath the foot during walking. Seventeen diabetic patients had dynamic foot pressure measurements made before and after the removal of a total of 43 forefoot plantar callosities. Peak pressures (mean +/- SE) in the treated areas were reduced by 26% from 14.2 +/- 1.0 to 10.3 +/- 0.9 kg cm-2 (p less than 0.001), with reductions at 37 of the 43 sites and in all patients. Mean heel pressures were not significantly different (5.0 +/- 0.6 vs 4.9 +/- 0.6 kg cm-2). These results suggest that callus may act as a foreign body elevating plantar pressures and that a significant reduction in pressure is achieved by local chiropody treatment.

Analysis of Variance↗