230517 Adaptation of Bone to Exercise
By Danny M. O’Dell, MA.CSCS*D
Background information-briefly stated
Bone is considered a connective tissue that when stressed, deforms and adapts as a result of the load. To meet the strain imposed upon the external structure caused by the bending, compressive, torsional loads and the muscular contractions at the tendinous insertion point’s osteoblasts migrate to the surface of the bone.
At the point of the strain, immediate modeling of the bone begins. Proteins form a matrix between the bone cells. This causes the bone to become denser due to the calcification process occurring during the growth response to the load.
The new growth occurs on the outside of the bone to allow the manufacture of new cells to continue in the limited space with in the bone itself. This outer layer is commonly known as the periosteum.
Adaptations take place at different rates in the axial skeleton (skull/cranium, vertebral, ribs, and sternum) and the appendicular skeleton (shoulder, hips, pelvis and the long bones of the upper and lower body-essentially the arms and legs). This is due to the differences in the bone types- trabecular (spongy) and cortical (compact) bone.