Baropodometric analysis in different feet positions: reliability and repeatability evaluation

Baropodometry is currently used in many sectors of human movement analysis in both clinical and sports fields. The effects induced on the gathered data by a different feet positions during static tests is still an open question as well as which position guarantees the most reliable and repeatable measures. Thus, the purpose of the study is firstly to test the reliability and repeatability of the baropodometric indices and, secondly, to evaluate their dependency with the position of the feet. Tests were conducted on height healthy subjects, asking them to perform static trials with four different feet positions among the most used in the literature. Each trial was repeated three times for each session and three sessions were performed one week apart. Inter-Class Correlation Coefficient was used to evaluate both the intra- and inter-day reliability, as well the standard deviation was assumed as the index of repeatability. The results showed excellent intra-day and inter-day reliability in almost all parameters analyzed and for all positions, especially regarding parameters related to pressure and footprint area. Lower values emerged for the podalic angle and the parameters concerning the load distribution. The orthostatic position proved to be the most repeatable and reliable. The ANOVA analysis highlighted differences between the self-selected position and the other ones. In conclusion, operator should select the orthostatic position when performing baropodometric analysis and compare obtained indices only if they have been gathered with the same feet positions.