Comparison of pedometer and accelerometer derived steps in older individuals with Parkinson's disease or osteoporosis under free-living conditions.

AIM: To compare self-reported pedometer steps with accelerometer steps under free-living conditions in individuals with Parkinson's disease (PD) or osteoporosis (OP). METHODS: Seventy-three individuals with PD and 71 individuals with OP wore a pedometer (Yamax LS2000) and an accelerometer (ActiGraph GT1M/GT3X+) simultaneously for one week. RESULTS: Fifty-one individuals with PD (72.6 ± 5.3 years) and 61 with OP (75.6 ± 5.3 years) provided simultaneously recorded data for 3-7 consecutive days. Pedometer steps were significantly lower than accelerometer steps in the PD group (p = .002) but not in the OP group (p = .956). Bland-Altman plots demonstrated wide limits of agreement between the instruments in both PD (range = 6,911 steps) and OP (range = 6,794 steps). CONCLUSION: These results suggest that the ActiGraph GT1M/GT3X+ should be preferred over the Yamax LS2000 for the assessment of steps in both research and clinical evaluations, particularly in individuals with PD or altered gait.