Abstract
BackgroundEarly childhood is a transferring stage between the two accelerated growth periods (infant and adolescent). Body dimensions are related to physical growth and development. The purpose of this study was to investigate physical growth in terms of anthropometry, muscle growth of the lower extremity, and functional development over early childhood.MethodsA cross-sectional study was carried out on 29 preschool children (PS: 3–5 years), 21 school children (SC: 6–8 years), and 22 adults (AD: 20–35 years). Lower extremity characteristics (segmental dimensions, muscle and adipose tissue thicknesses of the thigh and lower leg), and voluntary joint torque (knee and ankle) were measured. Correlations between parameters and group comparisons were performed.ResultsAll the parameters except for body mass index (BMI) and subcutaneous adipose tissue thickness were correlated with age for PS and SC combined (r = 0.479–0.920, p < 0.01). Relative thigh and shank lengths to body height were greatest in AD and smallest in PS (p < 0.05) but the relative foot dimensions were significantly larger in PS and SC than in AD (p < 0.05). Relative subcutaneous adipose tissue thickness was largest in PS and lowest in AD. Muscle thickness and the muscle volume measure (estimated from muscle thickness and limb length) were significantly larger in older age groups (p < 0.05). All groups showed comparable muscle thickness when normalized to limb length. Joint torque normalized to estimated muscle volume was greatest for AD, followed by SC and PS (p < 0.05).ConclusionsRelative lower extremity lengths increase with age, except for the foot dimensions. Muscle size increases with age in proportion to the limb length, while relative adiposity decreases. Torque-producing capacity is highly variable in children and rapidly develops toward adulthood. This cross-sectional study suggests that children are not a small scale version of adults, neither morphologically nor functionally.
Highlights
Growth and functional development as a function of chronological age have often been examined from birth to adolescence [1,2,3,4]
The age from three to eight years is defined as early childhood, and constitutes a period with relatively slower changes in body dimensions compared to the two growth phases before and after it that typically show accelerated growth
Age was positively correlated with body height, body mass, segmental dimension, muscle thickness, and joint torque (r = 0.479–0.920, p < 0.01)
Summary
Growth and functional development as a function of chronological age have often been examined from birth to adolescence [1,2,3,4]. Some growth-related parameters, such as bone dimensions, do not systematically change with chronological age [6,7,8], and the patterns of change can be different for muscle size [9,10,11], subcutaneous adipose tissue [9, 12, 13], and muscle strength [14, 15]. Segmental growth, muscularity, and adiposity might change to a greater degree than that of the whole body dimensions and may even result in greater changes in strength development. This issue has not been studied to date. The purpose of this study was to investigate physical growth in terms of anthropometry, muscle growth of the lower extremity, and functional development over early childhood
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
