I. SKELETAL SYSTEM ORGANIZATION
Bone is a biological marvel from Mother Nature; it makes vertebrates distinct from other life forms. Bone has the same strength as cast iron, but achieves this remarkable feat while remaining as light as wood. The front leg of a horse can withstand mechanical stress from heavy loads while this 1500-pound animal gallops at 40 miles per hour. The wing bone is able to keep birds aloft through entire migrations, sometimes over 10,000 miles without landing. The antlers of deer, used as weapons in territorial clashes with other deer, undergo tremendous impacts without a fracture – ready to fight another day. Without question, bone is the ultimate biomaterial. It is light, strong, adaptable to functional demands, and can repair itself.
Bones provide a rigid structure – the skeleton. Like an architectural framework, skeleton forms an internal structure that provides resistance to the force of gravity, move through space, and carry the physical body with grace and dignity. The large bones of the lower limbs support the trunk when standing. The fused bones of the cranium surround the brain to make it less vulnerable to injury. Vertebrae surround and protect the spinal cord and bones of the rib cage help protect the heart and lungs of the thorax. Bones work together with muscles as simple mechanical lever systems to produce body movement.
II. SKELETAL SYSTEM REPLENISHMENT
Bone Health is achieved during the childhood and adolescence, the skeletal forming years; and is established during young adult years of life. Management and functional up keeping of the bone health status is dependent on several factors including, nutrition, lifestyle, environment and age. Diet could affect the overall outcome of bone health. Malnutrition (low calcium, vitamin-D and trace mineral intake), oral hygiene and diabetes, can influence the bone health status. Addictive habits, such as tobacco consumption, smoking, alcohol, drug abuse, extreme dieting and certain medications could adversely affect bone health. Bones work on the ‘use it or lose it’ principle. Therefore, physical activities, especially, the weight-bearing exercises influence the strength and agility of the skeletal system. Indoor living (with little or no exposure to sunlight) and sedentary lifestyle could trigger a rapid bone loss. Aging is an ongoing biological phenomenon. Environmental factors (i.e. polluted air, water and land) and stress can take a cumulative toll on the body and cause rapid aging. Skeletal system is the primary target of an aging process. Sports, occupational and accidental injuries only worsen the aging bone. [Kiebzak 1991, US-DHHS 2000, Wright et al 2003].