Katie L J Cederberg1, Brenda Jeng2, Jeffer E Sasaki3, Byron Lai4, Marcas Bamman5, Robert W Motl2. 1. Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA; Department of Physical Therapy, University of Alabama at Birmingham, Birmingham, AL, USA. Electronic address: kcederb@stanford.edu. 2. Department of Physical Therapy, University of Alabama at Birmingham, Birmingham, AL, USA. 3. Department of Sport Sciences, Universidade Federal Do Triângulo Mineiro, Uberaba, MG, Brazil. 4. UAB/Lakeshore Foundation Research Collaborative, University of Alabama at Birmingham, Birmingham, AL, USA. 5. Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA.
Abstract
INTRODUCTION: Step counts represent a straight-forward method of measuring physical activity in adults with Parkinson's disease (PD). The present study examined the absolute and relative accuracy and precision of a wrist-worn research-grade accelerometer (i.e., ActiGraph GT3X+) for measuring step counts during over-ground and treadmill walking in adults with PD and controls without PD. METHODS: Participants (PD: n = 29; controls: n = 31) wore two ActiGraph GT3X + accelerometers, one on each wrist, and completed an over-ground walking bout followed by a treadmill walking bout at the same speed. Step counts were measured manually using a hand-held tally counter. Accuracy and precision were based on absolute and relative metrics. RESULTS: The ActiGraph GT3X + underestimated step counts in both participants with PD (4.7-11% error) and controls without PD (8.8-17% error), with a greater discrepancy in controls. The ActiGraph GT3X + provided more accurate and precise estimates of step counts when placed on the more affected wrist and non-dominant wrist for participants with PD and controls, respectively, and was more accurate and precise during over-ground walking compared with treadmill walking for both groups. CONCLUSIONS: Our results suggest that placement of the device (i.e., dominant vs. non-dominant), type of activity (i.e., over-ground vs. treadmill walking), and presence of clinical conditions may impact the accuracy and precision of data when using the research-grade ActiGraph GT3X + accelerometer for measuring step counts.
INTRODUCTION: Step counts represent a straight-forward method of measuring physical activity in adults with Parkinson's disease (PD). The present study examined the absolute and relative accuracy and precision of a wrist-worn research-grade accelerometer (i.e., ActiGraph GT3X+) for measuring step counts during over-ground and treadmill walking in adults with PD and controls without PD. METHODS: Participants (PD: n = 29; controls: n = 31) wore two ActiGraph GT3X + accelerometers, one on each wrist, and completed an over-ground walking bout followed by a treadmill walking bout at the same speed. Step counts were measured manually using a hand-held tally counter. Accuracy and precision were based on absolute and relative metrics. RESULTS: The ActiGraph GT3X + underestimated step counts in both participants with PD (4.7-11% error) and controls without PD (8.8-17% error), with a greater discrepancy in controls. The ActiGraph GT3X + provided more accurate and precise estimates of step counts when placed on the more affected wrist and non-dominant wrist for participants with PD and controls, respectively, and was more accurate and precise during over-ground walking compared with treadmill walking for both groups. CONCLUSIONS: Our results suggest that placement of the device (i.e., dominant vs. non-dominant), type of activity (i.e., over-ground vs. treadmill walking), and presence of clinical conditions may impact the accuracy and precision of data when using the research-grade ActiGraph GT3X + accelerometer for measuring step counts.
Authors: Christopher G Goetz; Barbara C Tilley; Stephanie R Shaftman; Glenn T Stebbins; Stanley Fahn; Pablo Martinez-Martin; Werner Poewe; Cristina Sampaio; Matthew B Stern; Richard Dodel; Bruno Dubois; Robert Holloway; Joseph Jankovic; Jaime Kulisevsky; Anthony E Lang; Andrew Lees; Sue Leurgans; Peter A LeWitt; David Nyenhuis; C Warren Olanow; Olivier Rascol; Anette Schrag; Jeanne A Teresi; Jacobus J van Hilten; Nancy LaPelle Journal: Mov Disord Date: 2008-11-15 Impact factor: 10.338
Authors: Byron Lai; Jeffer E Sasaki; Brenda Jeng; Katie L Cederberg; Marcas M Bamman; Robert W Motl Journal: JMIR Rehabil Assist Technol Date: 2020-01-16
Authors: Brenda Jeng; Katie L J Cederberg; Byron Lai; Jeffer E Sasaki; Marcas M Bamman; Robert W Motl Journal: Gait Posture Date: 2021-10-25 Impact factor: 2.840