Practical Considerations for the Use of the Pedobarograph

The pedobarograph functions as a device for the dynamic, quantitative measurement of pedal pressures. To date, little attention has been paid to various practical questions concerning its operation. For example, the number and timing of trials sufficient to provide meaningful information upon which to reliably base investigational or management decisions has yet to be addressed. Twenty volunteers were used for the measurement of pedal pressures for 15 trials during three separate sessions. Statistical analysis for the determination of MIVQUE(0) estimates and maximum likelihood estimates were used to determine the individual variability, the variability of the specific area of the foot, the daily variability, and the trial-to-trial variability. This analysis indicated that for the assessment of pedal pressures in a clinical setting, the variance factors were sufficiently minimized by obtaining multiple measurements. The improvement in the estimate of error by obtaining trials on different days was overshadowed by the potential benefit of doing extra trials on a single day. Three trials on 1 day should sufficiently reduce estimates of error for both clinical and investigational purposes.