Navicula drop test ad modum Brody: does it show how the foot moves under dynamic conditions?
BACKGROUND
Understanding foot motion and function during activity is essential for clinicians because different foot types may require different treatment or rehabilitation strategies. Brody introduced the static navicular drop (ND) test, which was meant as a quick clinical test to estimate foot pronation during dynamic conditions. However, how well static ND predicts dynamic ND during walking has never been investigated. The purpose of this study was to investigate how well static ND corresponds to dynamic measures of ND during treadmill walking.


METHODS
A custom video analysis system was used to assess dynamic ND during treadmill walking. The ND test ad modum Brody was used to evaluate static ND.


RESULTS
Static ND showed a significant correlation with dynamic ND (r = 0.357, r(2) = 0.127, P < .001). Navicular height at heel strike demonstrated a significant correlation with navicular height at the start position of static ND (r = 0.756, r(2) = 0.571 P < .001). Minimal navicular height during walking was significantly correlated with the end position of static ND (r = 0.951, r(2) = 0.904, P < .001).


CONCLUSIONS
This study of asymptomatic individuals did not confirm that static ND can be used to individually predict dynamic ND during treadmill walking. It was demonstrated that the start position of Brody's test is not well correlated with navicular height at heel strike, with this being the main reason for the weak relationship between static and dynamic ND measures.
Orthopaedic Surgery Research Unit, Aarhus University Hospital-Aalborg Hospital, Aalborg, Denmark. michaelrathleff@gmail.com
Michael Skovdal
MS
Rathleff
Rasmus Gottschalk
RG
Nielsen
Uwe G
UG
Kersting
D001696:Biomechanical Phenomena; D005080:Exercise Test / Q000379:methods*; D005260:Female; D005528:Foot / Q000503:physiopathology*; D005684:Gait / Q000502:physiology*; D006801:Humans; D008297:Male; D011403:Pronation; D015203:Reproducibility of Results; D013639:Tarsal Bones / Q000503:physiopathology*; D014743:Videotape Recording