Test-retest reliability of the IDEEA system in the quantification of step parameters during walking and stair climbing

The aim of this investigation was to evaluate the inter- and intra-session reliability of spatio-temporal gait variables collected during walking and stair climbing with the Intelligent Device for Energy Expenditure and physical Activity (IDEEA) accelerometer-based system. Eighteen healthy subjects (10 men, 8 women) completed a standardized indoor circuit comprised of walking and stair climbing. Intra- and inter-session reliability was investigated for several pertinent spatio-temporal gait variables using intraclass correlations [ICC (3,1)]. Intra- session reliability during walking showed a high reliability of the IDEEA with ICCs ranging between 0 84 (number of steps) and 0 97 (single limb support/double limb support). The ICCs for stair climbing were slightly lower than those during walking with values ranging between 0 74 (step duration) and 0 92 (number of steps). Inter-session reliability during walking showed a high reliability of the IDEEA between all trials, with values ranging between 0 87 (speed) to 0 98 (step duration). The ICCs of stair climbing were again lower than those during walking with values ranging from 0 64 (swing duration) to 0 79 (number of steps). The IDEEA accelerometer-based system provided a highly reliable measurement of spatio-temporal variables, in healthy subjects, during walking with moderately reduced correlations during stair climbing.