Body of evidence supporting the clinical use of 3D multisegment foot models: a systematic review.

BACKGROUND: A critical component in the characterization of foot mechanics during clinical gait analysis is the quantitative measurement of foot kinematics. Currently, the use of 3D multisegment foot models (3DMFMs) is popular in gait laboratories as it would seem to be an adequate tool for the in vivo analysis of dynamic foot kinematics. This systematic review identifies and evaluates current evidence for the use of 3DMFMs in clinical gait analysis.
METHODS: A targeted search strategy traced full papers that fulfilled the inclusion and exclusion criteria. The papers were classified and evaluated for quality using a custom made quality appraisal form.
FINDINGS: Forty-one manuscripts were included yielding a total number of fifteen 3DMFMs. Generally, study procedures and sample selection were adequately described; however, the methodological quality varied widely. Evidence regarding the repeatability of the identified models also varied widely. Models facing the highest level of scientific credibility were characterized by adequate repeatability indices obtained from between-trial, between-day and between and within assessor studies. Generally, the highest reliability indices were found for the sagittal plane kinematics. Within-subject variability was found to be the lowest, contrarily, between-subject and between-day variabilities were found to be highest.
INTERPRETATION: Reported repeatability indices such as the coefficient of multiple correlation, standard deviation and standard error of measurement provide evidence for the continued use of 3DMFMs. While a number of published models exist, there is no adequate evidence available to support their clinical use. More reliability and validity studies are needed to confirm adequate measurement properties of 3DMFMs.