title: The effect of load carriage on movement kinematics and respiratory parameters in children during walking.
abstract: The objective of this study was to investigate the influence of different backpack weights on trunk kinematics and respiratory parameters during walking in 10-year-old children. Fifteen boys with a mean age of 10.31 (0.26) years were selected from a primary school to participate in four walking trials on a treadmill: one with a backpack of 0% of body mass, and three whilst carrying backpacks that weighed 10%, 15%, and 20% of the child's body mass. The walking speed was set at 1.1 m s(-1) for 20 min duration. The walking movement was recorded on video and analysed in two dimensions. The breathing frequency, tidal volume, and respiratory muscles activity were measured with a cardiopulmonary system (Oxycon Champion, Jaeger) and a respiratory inductance plethysmograph (TR-601T, Nihon Kohden, Japan). A repeated ANOVA and Pearson correlation analysis were used to examine any significant differences in the measured parameters when comparing the different loads. The results showed a significant positive linear relationship between load weight, trunk inclination angle, and breathing frequency ( P<0.01). Walking for 20 min, carrying a load that weighed 20% of body mass induced a significantly increased trunk inclination angle. A significant increase in ventilation during walking with a backpack of 15% and 20% of bodymass was associated with a more rapid breathing frequency. Walking with a backpack of 10% body mass did not significantly change trunk posture or respiratory parameters. However, the results suggested that walking with a backpack of greater than 10% body mass induced significant changes in trunk posture and respiratory parameters in 10-year-old children.
authors.affiliation: Department of Sports Science and Physical Education, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong. lijx@cuhk.edu.hk
authors.forename: Jing Xian
authors.initials: JX
authors.lastname: Li
authors.forename: Youlian
authors.initials: Y
authors.lastname: Hong
authors.forename: Paul D
authors.initials: PD
authors.lastname: Robinson
mesh_terms: D000005:Abdomen / Q000502:physiology; D000222:Adaptation, Physiological / Q000502:physiology*; D000293:Adolescent; D001415:Back / Q000502:physiology; D001696:Biomechanical Phenomena / Q000379:methods; D005684:Gait / Q000502:physiology*; D006801:Humans; D008297:Male; D009068:Movement / Q000502:physiology; D010101:Oxygen Consumption / Q000502:physiology*; D011187:Posture; D012119:Respiration; D015656:Respiratory Mechanics / Q000502:physiology*; D012132:Respiratory Muscles / Q000502:physiology*; D016138:Walking / Q000502:physiology*; D016474:Weight-Bearing / Q000502:physiology*