Accuracy and precision of wrist-worn actigraphy for measuring steps taken during over-ground and treadmill walking in adults with Parkinson's disease

Step-Counting Accuracy of a Commercial Smartwatch in Mild-to-Moderate PD Patients and Effect of Spatiotemporal Gait Parameters, Laterality of Symptoms, Pharmacological State, and Clinical Variables

“…Thus, bradykinesia and tremors could lead to step counting underestimation or overestimation, respectively, in a different manner according to the laterality of symptoms. With this respect, only two previous reports evaluated this aspect using two commercial smartwatches (Garmin Vivosmart HR and Fitbit Charge HR) [ 25 ] or a research-grade actigraph (ActiGraph GT3X+) [ 43 ], and the results are in contrast with ours. The study from Lamont and colleagues [ 25 ] reported no significant differences between the steps recorded on the most-affected side and the least-affected one.…”

“…Conversely, the study from Cederberg and collaborators [ 43 ] showed that the accuracy of the investigated device was higher when it was worn on the side most-affected by the disease. The authors suggested that the reduced movement on this side in PD patients would be advantageous for a wrist-worn detector because the most-affected side could be considered as a “non-dominant” wrist, and a previous study on healthy participants reported a better accuracy in step counting while performing daily activities when the watch was worn on the non-dominant arm [ 43 ]. However, other studies reported no effect of wrist placement on step counting in the general unimpaired population [ 29 , 44 ].…”

Accuracy of Step Count Estimations in Parkinson’s Disease Can Be Predicted Using Ambulatory Monitoring

“…There has been interest in using ambulatory sensors to measure step count in PD since consumer grade devices providing this function first became available ( Lamont et al, 2018 ; Straiton et al, 2018 ; Wendel et al, 2018 ; Lai et al, 2020 ; Svarre et al, 2020 ; Cederberg et al, 2021 ). While gait laboratories can provide detailed information about gait in PD, the hope has been that ambulatory measurement in an ecologically relevant setting might provide other information that cannot be gained from laboratory measurements.…”

“…There have been studies of step count accuracy of wrist-worn sensors in PD ( Lamont et al, 2018 ; Straiton et al, 2018 ; Wendel et al, 2018 ; Lai et al, 2020 ; Svarre et al, 2020 ; Cederberg et al, 2021 ), but these regard PwP as a homogenous cohort with regard to risk of step count. However, this is unlikely because the well-known changes in walking and posture that occur as PD progresses are likely to lose the typical oscillatory energy produced by normal walking.…”

“…Although most studies of gait in PD have been conducted in laboratories, there has been increasing interest in ambulatory monitoring using sensors ( Weiss et al, 2015 ) mostly because behavior in one’s natural environment is likely to differ from the formal environment of the laboratory ( Robles-Garcia et al, 2015 ). Gait scores, particularly step count, have been assessed ( Lamont et al, 2018 ; Straiton et al, 2018 ; Lai et al, 2020 ; Svarre et al, 2020 ), and while error of ≤3% in step count can be obtained with ambulatory sensors at normal walking speeds, error rate increases when walking is slower or higher than normal ( Svarre et al, 2020 ) or discontinuous ( Wendel et al, 2018 ; Cederberg et al, 2021 ). The so-called “long walks” provided the greatest concordance and least error, and this may be because many of the devices use the quasi-periodic nature of the acceleration signal during walking.…”