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.