Gait Analysis using Wearable E-Textile Sock: an Experimental Study of Test-Retest Reliability

SWEET Sock is a wearable e-textile sock for gait analysis. It is based on the acquisition and digital processing of the angular velocities of the lower limbs. In this paper we focus on the study of test-retest reliability of this system in measuring spatio-temporal gait parameters. The analysis was simultaneously conducted on data acquired by a multicamera system for gait analysis (SMART-DX 700 by BTS), in order to have reference values. A group of healthy subjects, equipped with both systems, performed four repeated walking tests along an 11 m walkway, consecutively and under constant conditions. The four tests were repeated at preferred, slow and fast self-selected walking speed. The Intraclass Correlation Coefficient (ICC) and Minimum Detectable Change (MDC) were evaluated to assess the repeatability of the measures. ICC values range from moderate to excellent for all gait parameters assessed by smart socks. The novel system presents test-retest reliability values comparable to, if not higher than, those shown by the gold standard. Finally, the results of gait reliability as a function of walking speed show excellent ICCs and very low MDCs for all parameters evaluated on trials at fast velocity, supporting the referenced hypothesis that faster movement is more consistent.