A simpler device for measuring the mobility of the first ray of the foot

Since some devices can be cumbersome to use, we evaluated the validity and reliability of a specially designed device for easily checking the mobility of the first ray of the foot.

To analyze the validity of the device, the dorsal mobility of the first ray of the foot was measured with the modified Coleman block test developed by Fritz et al., the Klaue device, and the custom device. Two-tailed Student's paired t-test and Pearson correlation were used to compare the values of the two tests. For evaluation of inter- and intra observer reliability of the EMC device, 3 independent observers measured the dorsal mobility of the first ray of the foot twice. The results were analyzed with two-tailed Student's paired t-test and ANOVA to evaluate intraobserver and interobserver reliability, respectively.

For both the first and second examinations of reliability, the difference between the two values was significant (p < 0.05) for the Coleman block test but not significant (p = 0.118) in comparison with the Klaue device. The measurements from both examinations showed good correlation (Pearson correlation coefficient: comparison with the Coleman block test = 0.84 (p < 0.05), with the Klaue device = 0.92 (p < 0.05)). The paired t-test for intraobserver validity showed no statistically significant difference among observers (p = 0.52, 0.58, 0.96, Pearson correlation coefficient = 0.76, 0.79, 0.80), and ANOVA testing for interobserver reliability showed no significant difference either (p = 0.96, Pearson correlation coefficients = 0.83, 0.84, and 0.86, respectively).

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