MUSCKULOESKETAL DEVELOPMENT.pdf

Musculoskeletal development • Introduction • Skeleton • Skeletal muscle • Physical • Position of the center of gravity • Curves of the spine • Cranium • Upper limb • Lower limb Prof. Maria Martinez-Olagüe Jacome The developing musculoskeletal system is vulnerable to external influence at various...

Musculoskeletal development • Introduction • Skeleton • Skeletal muscle • Physical • Position of the center of gravity • Curves of the spine • Cranium • Upper limb • Lower limb Prof. Maria Martinez-Olagüe Jacome The developing musculoskeletal system is vulnerable to external influence at various stages of its pre- and postnatal development. Skeletal development. First trimester. • Cartilaginous skeletal template Skeletal development. Fetal period • Structures increase in size. • Risks: Morphologic abnormalities due to position constraints and abnormal mechanical forces. Skeletal development. Postnatal period Appositional • 2 types of bone growth Endochondral FIRST TRIMESTER FETAL PERIOD POSTNATAL PERIOD Cartilaginous skeletal template Structures increase in size. 2 types of bone growth. Risks: Congenital limb deficiencies Risks: Morphologic abnormalities due to position constraints and abnormal mechanical forces. Epiphyseal growth stimulated by intermitent compressive forces. Appositional growth stimulated by increased compressive forces. Joint- stimulated by motion. Skeletal Muscle development • Muscle growth occurs in tandem with bone growth. Height is related to the stage of growth. Growth rate fastest during pregnancy , first year of life and puberal growth spurt. Great increase in body mass composition till the end of the 1st year. Physical development Changes in the position of the center of gravity From the 12th thoraci vertebra to the 2nd sacral vertebra. Development of the curves of the spine DEVELOPMENT OF THE CURVES OF THE SPINE • Primary curves. Throacic spine and sacrum. • Seconday curves. Cervical and lumbar spine. DEVELOPMENT OF THE SKULL • Calvarial expansion is most pronounced during the first 2 years. • Growth continues until the age of 6 -7 years (90% of the adult size). Development of the upper limb • Most congenital upper limb defects have their origin during the appearance of the upper limb buds. Development of the lower limb • Developmental variations occur during infancy and childhood. They are commonly mistaken for deformities. Development of the lower limb • Hip joint • Femoral neck direction. • Knee genu varum/valgum • Tibial torsion • Foot and ankle Hip joint • At birth, the acetabulum covers less than half of the femoral head, which results in a relatively unstable hip. • During postnatal growth, the forces of compression and movement contribute to an increase in the depth of the acetabulum unitl the age of 10 years, when the adult level of femoral head cover-age is reached. Femoral neck direction • The direction of the femoral neck is characterized by two factors: its inclination and anteversion. Femoral neck-shaft angle • The femoral neck inclination decreases during human development from birth to adulthood from 150° (coxa valga) to approx. 130° Development of the femoral neck inclination when there is little movement and weight bearing Femoral neck anteversion or antetorsion This angle also declines during life from approx. 30° at birth to around 15° in adulthood The knee Tibial torsion • Internal tibial torsion is normal at birth, after which the tibiae rotates externally to about 15 degrees in adolescence. The foot and ankle • Infants are born with flexible flat feet due to the varus orientation of their ankle and foot complex, and the fat pads. • The development of the medial longitudinal arch (MLA) occurs between 2 and 6 years of age in earnest as the fat pad disappears and the gross motor skills of walking and single-limb stance activities develop. • By 10 years of age, MLA mature. • As the MLA develops, the calcaneus becomes more vertically oriented. • The immature musculoskeletal system is vulnerable to abnormal mechanical forces and pressures; alterations in the timing, direction, or magnitude of forces may have a deleterious effect on the growing and developing musculoskeletal system. • Immaturity of a child’s musculoskeletal system can also be an advantage. • Developmental variations occur during infancy and childhood.