Evaluating the Medial Longitudinal Arch of the Foot: Correlations, Reliability, and Accuracy in People With a Low Arch.

BACKGROUND: The medial longitudinal arch of the foot is a variable structure, and a decrease in its height could affect several functions and increase the risk of injuries in the lower limbs. There are many different techniques for evaluating it. OBJECTIVE: The objective of this study was to evaluate the correlations of the Navicular Drop Test, several footprint parameters, and the Foot Posture Index-6 in people with a low medial longitudinal arch. Intrarater reliability and interrater reliability were also estimated. DESIGN: This was a repeated-measures, observational descriptive study. METHODS: Seventy-one participants (53.5% women; mean age = 24.13 years; SD = 3.41) were included. All of the parameters were collected from the dominant foot. The correlation coefficients were calculated. The reliability was also calculated using the intraclass correlation coefficient, 95% CI, and kappa coefficient. RESULTS: Statistically significant correlations were obtained between the Navicular Drop Test and the footprint parameters, with r absolute values ranging from 0.722 to 0.788. The Navicular Drop Test and the Foot Posture Index-6 showed an excellent correlation (Spearman correlation coefficient = 0.8), and good correlations (Spearman correlation coefficient = |0.663-0.703|) were obtained between the footprint parameters and the Foot Posture Index-6. Excellent intrarater reliability and interrater reliability were obtained for all of the parameters. LIMITATIONS: Radiographic parameters, the gold standard for evaluating the medial longitudinal arch height, were not used. In addition, the results of this research cannot be generalized to people with normal and high medial longitudinal arches. CONCLUSIONS: In participants with a low medial longitudinal arch, the Navicular Drop Test showed significant correlations with footprint parameters; correlations were good for the arch angle and Chippaux-Smirnak Index, and excellent for the Staheli Index. The Foot Posture Index-6 showed an excellent correlation with the Navicular Drop Test and a good correlation with the footprint parameters evaluated. All of the parameters showed high reliability.

Prevalence of myofascial trigger points and diagnostic criteria of different muscles in function of the medial longitudinal arch.

OBJECTIVES: To evaluate the reliability of the used diagnostic criteria of latent trigger points (LTrPs) and pressure pain thresholds and to evaluate the prevalence of LTrPs in several muscles of the lower limb in subjects with a lower medial longitudinal arch (MLA) compared with controls. DESIGN: Cross-sectional study. SETTING: University campus. PARTICIPANTS: Subjects with a lower limb MLA (n=82) and controls (n=82) (N=164). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The navicular drop test was used to classify subjects with a lower MLA (≥10mm) and controls (5-9mm). The Simons et al recommended specific diagnostic criteria and pressure pain thresholds were used to evaluate the prevalence of LTrPs in several muscles of the lower limb, which was compared between the 2 groups. The reliability was evaluated using Cohen's kappa and intraclass correlation coefficient. The unpaired Student t test and chi-square test were used to evaluate the difference in the LTrP prevalence between the 2 groups. RESULTS: The intrarater reliability of the navicular drop test and the diagnosis of LTrPs was excellent, with the taut band and tender spot being the most reliable diagnostic criteria. In the lower MLA group, 60 subjects (73%) presented at least 1 LTrP whereas 57 controls (70%) presented at least 1 LTrP. The lower MLA group showed more LTrPs (4.46±4.10) than did controls (3.32±3.24) (P<.05). There were significantly (P<.05) more subjects with LTrPs in the flexor digitorum longus, tibialis anterior, and vastus medialis in the lower MLA group than in the control group. CONCLUSIONS: LTrPs are common in the lower limb muscles in both controls and subjects with a lower MLA. A lower MLA is associated with a higher prevalence of LTrPs, which are significant in the flexor digitorum longus, tibialis anterior, and vastus medialis.