The Reliability of Flexor Hallucis Longus Stretch Test in Subjects with Asymmetric Hallux Valgus Angles

Purpose: The flexor hallucis longus stretch test can determine the shortness of the flexor hallucis longus muscle by measuring the angle of extension in the first metatarsophalangeal (MTP) joint at maximum ankle dorsiflexion. Less than 30 degrees of the first MTP joint at the maximal ankle dorsiflexion indicates shortness of the flexor hallucis longus muscle. The purpose of this study was to examine the intraand inter-reliability of the flexor hallucis longus stretch test in subjects with asymmetric hallux valgus (HV) angles. Methods: Sixteen subjects with asymmetric HV angles participated in this study. In sitting position, dorsiflexion angles of the first MTP joint were measured with maximum ankle dorsiflexion on each side. ICC (3,1) and ICC (3,k) models were used, respectively, to assess the intra-reliability and inter-reliability of the flexor hallucis longus stretch test. The paired-t test was used to compare the dorsiflexion angle of the first MTP joint on the side with the smaller HV angle with that of the side with the larger HV angle. Results: The results of the study showed that both intraand inter-reliability were more than 0.95 of the coefficient. Dorsiflexion angle of the first MTP joint was higher on the side with the smaller HV angle. Conclusion: Use of the flexor hallucis longus stretch test is acceptable in clinical settings because both intraand inter-reliability were high in subjects with asymmetric HV angles. In addition, shortness of the flexor hallucis longus muscle is associated with HV angle. This study provides useful information for use in management of HV deformity.