Alternative techniques for the clinical assessment of foot pronation.

Clinical measurement is a fundamental component of podiatric biomechanics. However, recent research has seriously questioned the reliability and validity of the commonly used approaches to clinical measurement of foot posture. A reevaluation of foot-morphology measurement is therefore warranted. This article discusses alternative clinical techniques of measuring foot type reported in the literature (arch height, footprint indices, the valgus index, and navicular drop) that may prove to be superior to the commonly used podiatric measurement system. On the basis of a critical evaluation of the literature, it would appear that arch height and footprint indices are invalid as means of categorizing foot morphology, while the valgus index and navicular drop offer a number of benefits over traditional frontal-plane measurements. An additional clinical measurement suggested by the author, navicular "drift," is also introduced. The advantages, disadvantages, and clinical application of each of these approaches are discussed in detail.