Accuracy and reliability of a technique for quantifying foot shape, dimensions and structural characteristics

A technique using a three-dimensional digitizing device for the measurements of foot dimension, shape and structural characteristics was developed. A total of 23 variables were calculated from the coordinates of 26 digitized points on the foot and the leg when body weight was supported mainly by one foot as the other foot was resting on a platform. All variables were measured with reference to an anatomically defined reference frame on the foot. The intra- and intertester reliability were tested both for the device and for the foot measurements. High reliability (ICC> 0.999) was found for the device in measuring distances and angles on a plastic cube. Intra- and intertester reliability for the foot measurements were high (ICC> 0.8) in most of the variables, with the lowest intratester reliability of 0.57 and the lowest intertester reliability of 0.38.