ABSTRACT
Chronological age is a poor marker of biological maturity in children. There are considerable varieties of physical characteristics among children of the same chronological age.57,201,407 The processes of growth and biological maturation are related, and both influence physical performance in children.57 According to Viru et al.,656 the first critical period of biological maturation in regard to motor function is in infancy or early childhood. The second critical period appears at the age of 7 to 9, and the third critical period is during puberty.656 Biological maturity of children can be estimated by different techniques that vary depending on the biological system being assessed. Most common systems include skeletal maturation, sexual maturation, and somatic (physique) maturation.57,201,407,409
Skeletal maturation is the best method to assess biological age or maturity status in children.57,201,407 The skeleton develops from cartilage in the prenatal period to fully developed bone in early adulthood and serves as an easily identifiable indicator of biological maturation.201,419,530 The assessment
of skeletal age is based on the fact that a more mature child has more bone development and less cartilage than a less advanced child.201,419,530 Bones of the extremities develop progressively during the growing years by ossification of cartilage.419,530 Growth of these long bones occurs through proliferation of cartilage cells in the epiphyseal plate.419,530 The mature adult state is reached when multiplication of these cells ceases and the bone fully ossifies.201,419,530
The x-ray of the hand-wrist area of the left hand is the site most often used to determine the amount of bone development and how near the shapes and contours of the bones are to adult status. The hand-wrist area of the left hand is ideal because it contains multiple bones for examination and is reasonably typical of the skeleton as a whole. Furthermore, the radiation exposure is minimal.
