title: Investigation of treadmill and overground running: implications for the measurement of oxygen cost in children with developmental coordination disorder.
abstract: Differences in the kinematics and kinetics of overground running have been reported between boys with and without developmental coordination disorder (DCD). This study compared the kinematics of overground and treadmill running in children with and without DCD to determine whether any differences in technique are maintained, as this may influence the outcome of laboratory treadmill studies of running economy in this population. Nine boys with DCD (10.3 ± 1.1 year) and 10 typically developing (TD) controls (9.7 ± 1 year) ran on a treadmill and overground at a matched velocity (8.8 ± 0.9 km/h). Kinematic data of the trunk and lower limb were obtained for both conditions using a 12-camera Vicon MX system. Both groups displayed an increase in stance time (p < 0.001), shorter stride length (p < 0.001), higher cadence (p < 0.001) and reduced ankle plantar flexion immediately after toe-off (p < 0.05) when running on the treadmill compared with overground. The DCD group had longer stance time (p < 0.009) and decreased knee flexion at mid-swing (p = 0.04) while running overground compared to their peers, but these differences were maintained when running on the treadmill. Treadmill running improved ankle joint symmetry in the DCD group compared with running overground (p = 0.019). Overall, these findings suggest that there are limited differences in joint kinematics and lower limb symmetry between overground and treadmill running in this population. Accordingly, laboratory studies of treadmill running in children with DCD are likely representative of the energy demands of running.
authors.affiliation: School of Sport Science, Exercise and Health, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia. Electronic address: esther.chia.lc@gmail.com.
authors.forename: L C
authors.initials: LC
authors.lastname: Chia
authors.affiliation: School of Sport Science, Exercise and Health, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia.
authors.forename: M K
authors.initials: MK
authors.lastname: Licari
authors.affiliation: School of Sport Science, Exercise and Health, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia.
authors.forename: K J
authors.initials: KJ
authors.lastname: Guelfi
authors.affiliation: School of Sport Science, Exercise and Health, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia.
authors.forename: S L
authors.initials: SL
authors.lastname: Reid
mesh_terms: D000293:Adolescent; D001696:Biomechanical Phenomena / Q000502:physiology; D016022:Case-Control Studies; D002648:Child; D004734:Energy Metabolism; D005080:Exercise Test; D006801:Humans; D035002:Lower Extremity / Q000503:physiopathology*; D008297:Male; D018670:Monitoring, Ambulatory; D019957:Motor Skills Disorders / Q000503:physiopathology*; D010101:Oxygen Consumption / Q000502:physiology*; D012420:Running / Q000502:physiology*
keywords: Children; Developmental coordination disorder; Kinematics; Symmetry; Treadmill running