Research

Reliability and normative values for the foot mobility magnitude: a composite measure of vertical and medial-lateral mobility of the midfoot

Thomas G McPoil¹ , Bill Vicenzino² , Mark W Cornwall¹ , Natalie Collins² and Meghan Warren¹

¹  Gait Research Laboratory, Program in Physical Therapy, Northern Arizona University, Flagstaff, Arizona, USA

²  Department of Physiotherapy, University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia

author email corresponding author email

Journal of Foot and Ankle Research 2009, 2:6doi:10.1186/1757-1146-2-6

Published:	6 March 2009

Abstract

Background

A study was conducted to determine the reliability and minimal detectable change for a new composite measure of the vertical and medial-lateral mobility of the midfoot called the foot mobility magnitude.

Methods

Three hundred and forty-five healthy participants volunteered to take part in the study. The change in dorsal arch height between weight bearing and non-weight bearing as well as the change in midfoot width between weight bearing and non-weight bearing were measured at 50% of total foot length and used to calculate the foot mobility magnitude. The reliability and minimal detectable change for the measurements were then determined based on the assessment of the measurements by three raters with different levels of clinical experience.

Results

The change in dorsal arch height between weight bearing and non-weight bearing, midfoot width between weight bearing and non-weight bearing, and the foot mobility magnitude were shown to have high levels of intra-rater and inter-rater reliability. Normative data are provided for the left and right feet of both the female (n = 211) and male (n = 134) subjects.

Conclusion

While the measurements of navicular drop and drift have been used as a clinical method to assess both the vertical and medial-lateral mobility of the midfoot, poor to fair levels of inter-rater reliability have been reported. The results of the current study suggest that the foot mobility magnitude provides the clinician and researcher with a highly reliable measure of vertical and medial-lateral midfoot mobility.