Background and aim: This study was aimed to examine the reliability of a developed device measuring "arch height ratio" index.

Materials and Methods: 40 feet (the right and left foot of 20 subjects) were measured. Foot length was measured from posterior aspect of calcaneus to the tip of longest toe and dorsum height was measured at the midpoint of total foot length. All measurements were assessed in three weight bearing conditions of 10, 50 and 90 percent of total body weight on three occasions (10 minutes and five days after the first measurement) by a single rater. Finally the arch height ratio index was calculated.

Results: The ICC values in different conditions of 10, 50 and 90 percent of total body weight in 10 minutes after the first measurement were calculated 0.96, 0.97 and 0.92 and in five days after the first measurement were calculated 0.97, 0.97 and 0.91. Minimal detectable change values of arch height ratio index in all conditions of measurement were 0.01.

Conclusion: Simplicity of usage, low cost and high reliability of this device is highly recommended for clinical and research use.