title: Medial Longitudinal Arch Angle Presents Significant Differences Between Foot Types: A Biplane Fluoroscopy Study.
abstract: The structure of the medial longitudinal arch (MLA) affects the foot's overall function and its ability to dissipate plantar pressure forces. Previous research on the MLA includes measuring the calcaneal-first metatarsal angle using a static sagittal plane radiograph, a dynamic height-to-length ratio using marker clusters with a multisegment foot model, and a contained angle using single point markers with a multisegment foot model. The objective of this study was to use biplane fluoroscopy to measure a contained MLA angle between foot types: pes planus (low arch), pes cavus (high arch), and normal arch. Fifteen participants completed the study, five from each foot type. Markerless fluoroscopic radiostereometric analysis (fRSA) was used with a three-dimensional model of the foot bones and manually matching those bones to a pair of two-dimensional radiographic images during midstance of gait. Statistically significant differences were found between barefoot arch angles of the normal and pes cavus foot types (p = 0.036), as well as between the pes cavus and pes planus foot types (p = 0.004). Dynamic walking also resulted in a statistically significant finding compared to the static standing trials (p = 0.014). These results support the classification of individuals following a physical assessment by a foot specialist for those with pes cavus and planus foot types. The differences between static and dynamic kinematic measurements were also supported using this novel method.
authors.forename: Megan E R
authors.initials: ME
authors.lastname: Balsdon
authors.forename: Kristen M
authors.initials: KM
authors.lastname: Bushey
authors.forename: Colin E
authors.initials: CE
authors.lastname: Dombroski
authors.forename: Marie-Eve
authors.initials: ME
authors.lastname: LeBel
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Jenkyn
mesh_terms: D000293:Adolescent; D059925:Anatomic Landmarks / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D005471:Fluoroscopy / Q000379:methods*; D005528:Foot / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult