Abnormal motion of the hindfoot during walking has been indicated as an aetiological component of many foot and lower limb pathologies. Diagnosis of such motion commonly involves the measurement of static weight bearing calcaneal positions, the underlying assumption being that the frontal plane position of the calcaneum is indicative of the alignment of the subtalar joint. For such a procedure to have useful clinical application and scientific credibility, its reliability and validity must first be established. In the case of hindfoot measurement, reliability and validity are dependent on both the underlying concepts of subtalar joint motion and the measurement procedure itself. A review of the relevant literature found that the validity of the subtalar joint neutral position is questionable, as is the reliability of static hindfoot measurements. This discussion highlights the subjective nature of biomechanical assessment, and questions whether such a procedure is of any significant clinical application.