Finally, we measure gait variability using a 6-meter gait test and the GAITRite system (CIR Systems, Sparta, NJ, USA). There are two separate tests. The first is conducted using self-selected speed without performing any tasks. The second is performed at a self-selected speed while performing a dual-task to increase the involvement of higher cortical functions on the gait variability. Balance and gait are of interest in the present project as measures of frailty, and of interest with respect to the risk of falls and fractures.