This study demonstrated that the EMC device is both reliable and valid for measuring the mobility of the first ray of the foot.

Clinically, the dorsiflexion mobility of the first ray was significantly reduced after correction of hallux valgus with PMCO with DSTP. Because the stability of the first ray can be improved with PMCO with DSTP, the surgical indication for this procedure could include some patients showing hypermobility of the first ray.

Clinically, the dorsiflexion mobility of the first ray was significantly reduced after correction of hallux valgus with PMCO with DSTP. Because the stability of the first ray can be improved with PMCO with DSTP, the surgical indication for this procedure could include some patients showing hypermobility of the first ray.

Purpose: To evaluate the validity and intra-rater, inter-rater reliability of the EMC device used to check the mobility of the first ray of the foot. Materials and Methods: Sixty-nine cases (43 patients) of mild to severe hallux valgus feet were enrolled in this study. For an analysis of the validity of the EMC device, the dorsal mobility of the first ray of the foot was measured using the modified Coleman block test and EMC device. The intra-and inter-rater reliability of EMC device was evaluated by measuring the dorsal mobility of the first ray of the foot twice with three independent raters blinded to other's results. The results were analyzed for the intra-rater reliability and for inter-rater reliability. .