Back extensor muscle strengthening

FIG. 55-18 Back extensor muscle strengthening, right arm and right leg raised. 

FIG. 55-21 Back extensor muscle strengthening, all extremities raised. 

FIG. 55-19 Back extensor muscle strengthening, both arms raised. 

These curves are physiologic and biomechanical and were created by the body s functional development. At birth, the cervical, thoracic, and lumbar vertebrae form one continuous kyphotic (concave forward) curve. As the cervical extensor muscles develop, allowing the head to stay raised, the norm cervical (convex forward) lordosis develops. As the child begins to stand and walk, the back muscles strengthen and normal lumbar lordosis (convex forward) is achieved. This process begins at approximately age 3 years and is fully developed by the age 10 years. The thoracic spine retains its kyphotic posture, but the angle of the curve is usually decreased. 

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