title: Impact of an 8-Month Trial Using Height-Adjustable Desks on Children's Classroom Sitting Patterns and Markers of Cardio-Metabolic and Musculoskeletal Health.
abstract: During school hours, children can sit for prolonged and unbroken periods of time. This study investigated the impact of an 8-month classroom-based intervention focusing on reducing and breaking-up sitting time on children's cardio-metabolic risk factors (i.e., body mass index, waist circumference, blood pressure) and perceptions of musculoskeletal discomfort. Two Year-6 classes (24 students per class) in one primary school were assigned to either an intervention or control classroom. The intervention classroom was equipped with height-adjustable desks and the teacher was instructed in the delivery of pedagogical strategies to reduce and break-up sitting in class. The control classroom followed standard practice using traditional furniture. At baseline, and after 8-months, time spent sitting, standing, stepping, and sitting-bouts (occasions of continuous sitting) as well as the frequency of sit-to-stand transitions were obtained from activPAL inclinometers and the time spent in light-intensity physical activity was obtained from ActiGraph accelerometers. Demographics and musculoskeletal characteristics were obtained from a self-report survey. Hierarchical linear mixed models found that during class-time, children's overall time spent sitting in long bouts (>10 min) were lower and the number of sit-to-stand transitions were higher in the intervention group compared to the control group, while no changes were observed for musculoskeletal pain/discomfort. No significant intervention effects were found for the anthropometrics measures and blood pressure. Height-adjustable desks and pedagogical strategies to reduce/break-up sitting can positively modify classroom sitting patterns in children. Longer interventions, larger and varied sample size may be needed to show health impacts; however, these desks did not increase musculoskeletal pain/discomfort.
authors.affiliation: Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Burwood, VIC 3125, Australia. a.contardoayala@deakin.edu.au.
authors.forename: Ana María
authors.initials: AM
authors.lastname: Contardo Ayala
authors.affiliation: Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Burwood, VIC 3125, Australia. jo.salmon@deakin.edu.au.
authors.forename: Jo
authors.initials: J
authors.lastname: Salmon
authors.affiliation: Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Burwood, VIC 3125, Australia. anna.timperio@deakin.edu.au.
authors.forename: Anna
authors.initials: A
authors.lastname: Timperio
authors.affiliation: Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Burwood, VIC 3125, Australia. b.sudholz@deakin.edu.au.
authors.forename: Bronwyn
authors.initials: B
authors.lastname: Sudholz
authors.affiliation: Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Burwood, VIC 3125, Australia. nicky.ridgers@deakin.edu.au.
authors.forename: Nicola D
authors.initials: ND
authors.lastname: Ridgers
authors.affiliation: Physical Activity Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, VIC 3004, Australia. Parneet.Sethi@bakeridi.edu.au.
authors.forename: Parneet
authors.initials: P
authors.lastname: Sethi
authors.affiliation: Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Burwood, VIC 3125, Australia. David.Dunstan@bakeridi.edu.au.|Physical Activity Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, VIC 3004, Australia. David.Dunstan@bakeridi.edu.au.|Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC 3000, Australia. David.Dunstan@bakeridi.edu.au.
authors.forename: David W
authors.initials: DW
authors.lastname: Dunstan
mesh_terms: D061725:Accelerometry; D001794:Blood Pressure; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control*; D002648:Child; D006804:Ergonomics; D015444:Exercise; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007374:Interior Design and Furnishings; D016014:Linear Models; D008297:Male; D008659:Metabolic Diseases / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control*; D059352:Musculoskeletal Pain / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control*; D010865:Pilot Projects; D011187:Posture; D012307:Risk Factors; D012574:Schools; D057185:Sedentary Behavior; D016896:Treatment Outcome; D055105:Waist Circumference
keywords: anthropometric measures; blood pressure; classroom-based intervention; height-adjustable desks; musculoskeletal health; school-age children; sitting time