Test-Retest Reliability of Movement Displacement during a 20-s Stepping-in-Place Test in Community-Dwelling Older Adults with and without Supportive Care

Abstract

<b><i>Introduction:</i></b> Our recent reports have shown that movement pattern and displacement assessed with an infrared depth sensor during a 20-s stepping-in-place test (ST) correlates with measures of balance and need for assistance in older individuals. This study investigated ST test-retest reliability in community-dwelling older adults with and without supportive care. <b><i>Methods:</i></b> Two groups were included: those not participating (HO: <i>n</i> = 25, 74.7 ± 5.2 years) and those participating (DSU: <i>n</i> = 41, 78.8 ± 5.8 years) in regular senior day services (supportive care). HO completed three ST trials, separated by 1 week, while DSU completed two ST trials during the same half-day supportive care visit. Testing was conducted with eyes open. ST measures included head movement path distance (TMD), maximum movement displacement (MMD), knee movement path length (KMD), and stepping rate (STEP). TMD×KMD⁻¹ ratio indicated upper-body sway relative to lower-body. Test-retest reliability (intra-class correlation coefficients, ICCs) and between-trial and between group differences (ANCOVA, adjusting for age) were assessed. <b><i>Results:</i></b> After adjusting for age, TMD, KMD, TMD×KMD⁻¹ were lesser and STEP was greater in HO than DUS. HO ST variables did not differ across testing days. HO ICC (1, 3) for TMD (0.911 [95% confidence interval: 0.827–0.958]), MMD (0.918 [0.814–0.961]), KMD (0.838 [0.685–0.923]), and TMD×KMD⁻¹ (0.940 [0.884–0.872]) showed strong to very strong reliability. Similarly, DSU ST variables did not differ across same day trials and ICC (1, 2) for TMD, KMD, and TMD×KMD⁻¹ displayed very strong reliability. <b><i>Conclusion:</i></b> These ST variables exhibited excellent test-retest reliability of discriminating between community-dwelling older adults with and without supportive care.