TY - JOUR
T1 - Validating accelerometry as a measure of physical activity and energy expenditure in chronic stroke
AU - Serra, Monica C.
AU - Balraj, Elizabeth
AU - DiSanzo, Beth L.
AU - Ivey, Frederick M.
AU - Hafer-Macko, Charlene E.
AU - Treuth, Margarita S.
AU - Ryan, Alice S.
N1 - Funding Information:
This study was supported by Veterans Affairs (VA) Merit, Senior Research Career Scientist, and CDA-2 Awards, NIH R01-AG030075, NIH 5T35AG036679, the National Institute on Aging (NIA) Claude D. Pepper Older Americans Independence Center (P30-AG028747), Baltimore VA Research Service, Geriatric Research, Education and Clinical Center (GRECC), Maryland Exercise and Robotics Center of Excellence (MERCE).
Publisher Copyright:
© 2016 Informa UK Limited, trading as Taylor & Francis Group.
PY - 2017
Y1 - 2017
N2 - Background: Accelerometers can objectively measure steps taken per day in individuals without gait deficits, but accelerometers also have the ability to estimate frequency, intensity, and duration of physical activity. However, thresholds to distinguish varying levels of activity intensity using the Actical brand accelerometer are standardized only for the general population and may underestimate intensity in stroke. Objective: To derive Actical activity count thresholds specific to stroke disability for use in more accurately gauging time spent at differing activity levels. Methods: Men (n = 18) and women (n = 10) with chronic hemiparetic gait (4 ± 2 years latency, 43% Caucasian, 56% African-American, ages of 47–83 years, BMI 19–48 kg/m2) participated in the study. Actical accelerometers were placed on the non-paretic hip to obtain accelerometry counts during eight activities of varying intensity: (1) watching TV; (2) seated stretching; (3) standing stretching; (4) floor sweeping; (5) stepping in place; (6) over-ground walking; (7) lower speed treadmill walking (1.0 mph at 4% incline); and (8) higher speed treadmill walking (2.0 mph at 4% incline). Simultaneous portable monitoring (Cosmed K4b2) enabled quantification of energy cost for each activity in metabolic equivalents (METs, or oxygen consumption in multiples of resting level). Measurements were obtained for 10 min of standard rest and 5 min during each of the eight activities. Results: Regression analysis yielded the following new stroke-specific Actical minimum thresholds: 125 counts per minute (cpm) for sedentary/light activity, 667 cpm for light/moderate activity, and 1546 cpm for moderate/vigorous activity. Conclusion: Our revised cut points better reflect activity levels after stroke and suggest significantly lower thresholds relative to those observed for the general population of healthy individuals. We conclude that the standard, commonly applied Actical thresholds are inappropriate for this unique population.
AB - Background: Accelerometers can objectively measure steps taken per day in individuals without gait deficits, but accelerometers also have the ability to estimate frequency, intensity, and duration of physical activity. However, thresholds to distinguish varying levels of activity intensity using the Actical brand accelerometer are standardized only for the general population and may underestimate intensity in stroke. Objective: To derive Actical activity count thresholds specific to stroke disability for use in more accurately gauging time spent at differing activity levels. Methods: Men (n = 18) and women (n = 10) with chronic hemiparetic gait (4 ± 2 years latency, 43% Caucasian, 56% African-American, ages of 47–83 years, BMI 19–48 kg/m2) participated in the study. Actical accelerometers were placed on the non-paretic hip to obtain accelerometry counts during eight activities of varying intensity: (1) watching TV; (2) seated stretching; (3) standing stretching; (4) floor sweeping; (5) stepping in place; (6) over-ground walking; (7) lower speed treadmill walking (1.0 mph at 4% incline); and (8) higher speed treadmill walking (2.0 mph at 4% incline). Simultaneous portable monitoring (Cosmed K4b2) enabled quantification of energy cost for each activity in metabolic equivalents (METs, or oxygen consumption in multiples of resting level). Measurements were obtained for 10 min of standard rest and 5 min during each of the eight activities. Results: Regression analysis yielded the following new stroke-specific Actical minimum thresholds: 125 counts per minute (cpm) for sedentary/light activity, 667 cpm for light/moderate activity, and 1546 cpm for moderate/vigorous activity. Conclusion: Our revised cut points better reflect activity levels after stroke and suggest significantly lower thresholds relative to those observed for the general population of healthy individuals. We conclude that the standard, commonly applied Actical thresholds are inappropriate for this unique population.
KW - Accelerometry
KW - Chronic stroke
KW - Physical activity
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U2 - 10.1080/10749357.2016.1183866
DO - 10.1080/10749357.2016.1183866
M3 - Article
C2 - 27322733
AN - SCOPUS:85034591075
SN - 1074-9357
VL - 24
SP - 18
EP - 23
JO - Topics in Stroke Rehabilitation
JF - Topics in Stroke Rehabilitation
IS - 1
ER -