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Bones: Round 2. Andrew Richards & Ryan Swenson. Peak Functional Levels. Quantity of bone increases through life until skeletal maturity – Age 20-30 Peak Bone Mass is reached at this point “Bone Bank” used for remainder of life Growth rates differ at different sites
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Bones: Round 2 Andrew Richards & Ryan Swenson
Peak Functional Levels • Quantity of bone increases through life until skeletal maturity – Age 20-30 • Peak Bone Mass is reached at this point • “Bone Bank” used for remainder of life • Growth rates differ at different sites • Most rapid growth during adolescence • About 25% of PBM achieved during adolescent growth spurt
Peak Functional Levels • Factors • Gender: • Men larger skeletons than women= larger “bank” • Women reach their peak sooner • Have lower BMD • Hereditary: • ¾ of skeletal characteristics • Environmental Factors • Strain placed on skeleton (Wolff’s Law) • Activities such as smoking can negatively impact
Increasing/Decreasing Levels • Occurs during the process of bone remodeling along with natural growth • Resorption, reversal, and formation • Osteoclasts, osteoblasts, osteocytes, etc.
Increasing/Decreasing Levels • Remodeling process based off Wolff’s Law • Julius Wolff: German anatomist and surgeon • States that bone in a healthy person will adapt to the loads to which it is placed • Heavy Loads=increased levels • Long Term Immobilized=decreased levels
Dysfunctional Levels • As body ages bone levels decrease • Additionally, factors can increase the rate
Dysfunctional Levels • Osteopenia: low bone mass • Occurs naturally to some degree with aging • Women lose roughly 8% per decade • Men lose roughly 3% per decade
Dysfunctional Levels • Osteoporosis: Decreased bone strength compromising normal function, predisposing to an increased risk of fracture • Change in structure of trabecular bone • Relationship to common fracture sites • Spine, wrists, and hips
References http://www.ncsf.org/pdf/ceu/establishing-peak-bone-mass.pdf http://www.ncbi.nlm.nih.gov/books/NBK45504/