Is a low cost electronic measure of balance as valid as a force platform in distinguishing the balance performance of a healthy and a clinical older population?

This study seeks to determine concurrent validity of the CSMi HUMAC (Registered Trademark) Balance device against a ‘gold standard’ force platform measurement (Neurocom EquiTest (Registered Trademark) System). The 2 different devices will be used to assess balance in 2 populations: 1. a healthy group of community dwelling individuals aged >60 years (N=20); 2. a group of community dwelling individuals aged >60 who have had a stroke (subacute or chronic, ie > 6 weeks post stroke)(N=20). In a randomized order, subjects will undergo an assessment on each device over the course of about 1 hour. Assessment on the HUMAC device will include a modified Clinical Test of Sensory Interaction on Balance (mCTSIB) and a Limits of Stability (LOS) test. On the NeuroCom device a modified Sensory Organization Test (mSOT) and a LOS test will be performed. The mCTSIB and mSOT each have 4 conditions inwhich a subject stands still and has their balance assessed. The conditions include standing eyes open on a stable surface, standing eyes close on a stable surface, standing eyes open on a compliant surface, and standing eyes closed on a compliant surface. LOS testing requires subjects to stand still and then shift there weight as far as possible in 8 directions (N,NW,W,SW,S etc). Subjects will be given 3 minute rests between each test condition on either device as well as 5 minute rest when changing between devices.