At the time of birth, the bones of the skeleton are not yet fully formed, and many of them consist of cartilaginous tissue.
Pelvic Girdle: In a newborn, each pelvic bone consists of three bones (ilium, pubis, ischium), the fusion of which begins around 5-6 years of age and is completed by 17-18 years. After 9 years, differences in the shape of the pelvis are observed between boys and girls, with boys having a higher and narrower pelvis than girls.
Upper and lower limbs in infants have almost the same length and are relatively short. The bones of newborns’ limbs are elastic, containing relatively few mineral salts and a relatively large amount of water. Only the diaphyses of tubular bones ossify due to primary ossification centers. The appearance of secondary ossification centers in the epiphyses of tubular bones is observed in children at 1-2 years, in apophyses at 3-4 years, and in sesamoid bones at 5-8 years, although there are exceptions to this rule in individual bones. Complete ossification of epiphyses occurs around 5 years, apophyses around 7-8 years, and sesamoid bones around 12 years.
Clavicles are stable bones, showing little change during ontogeny. Ossification of the scapula, clavicle, humerus, and forearm bones continues until 20-25 years, wrists and metacarpal bones until 15-16 years, and phalanges until 16-20 years.
Scapular ossification in postnatal ontogeny is completed after 16-18 years.
The wrist bones begin to emerge and become visible by the age of 7. Sexual differences in the ossification process appear between 10-12 years, with boys showing a 1-year delay. Phalangeal ossification is completed at 11 years, and wrist bones at 12 years.
The bone marrow cavity in long tubular bones is nearly absent in newborns and intensively develops only between 2 and 5-7 years.
Foot: In a newborn, the arch of the foot is not well defined, and it develops later when the child starts to walk.
Conclusively, dynamic gymnastics for babies are not physiologic and not advised. Understanding the age-specific characteristics of skeletal development underscores the importance of nurturing a child’s growth with care and caution
