Bone and Joint Disease
The preconditions for retaining mobility well into old age are well functioning bones and joints. Together with the muscles, tendons and ligaments, they provide the body with support, flexibility and mobility.
Osteoporosis and osteoarthritis are two very widespread diseases that are often responsible for impairment of mobility in bones and joints. The World Health Organization (WHO) in fact has designated osteoporosis as one of the top ten disabling diseases affecting mankind.
Apart from primary osteoporosis, there is another type - secondary osteoporosis. Secondary osteoporosis differs from primary osteoporosis in that it is initiated by specific factors such as metabolic disturbances or the long-term administration of medicines containing cortisone.
Osteoporosis - The Slow Loss of Bone Mass
How do our bones function?
The human skeleton comprises some 200 bones of different sizes and appearance.
Healthy bone can resist a high degree of traction, pressure, flexure and torsion. Bones have many tasks. They enable us to stand upright and carry the weight of the body. They are the anchor points for muscles and tendons. they protect internal organs, the spinal cord and bone marrow and they act as a reservoir for calcium, magnesium and phosphorus - adult bone contains up to 1.5 kg of calcium which can be called upon in times of deficiency.
At first glance, bones give the impression of being hard, inflexible and lifeless body parts. However, this is a misconception; numerous renewal processes take place within the bones. Three types of bone cell are involved in these processes: the osteoblasts, the osteoclasts and the osteocytes.
All three are characterized by their ability to operate in perfect harmony. The osteocytes register the tiniest injuries to the bones and inform the osteoblasts. These then control the osteoclasts, the bone-forming cells. The osteoclasts remove the damaged tissue leaving tiny empty pores.
These are then filled by the osteoblasts. In doing so, the osteoblasts first form collagen, a protein that makes up the bone matrix and that can be regarded as a sort of soft bone material. Hardening is brought about by calcification or mineralisation with the help of calcium and phosphate which are ingested along with food and are stored in the collagen matrix. Bone metabolism is controlled by a number of hormones.
The most important of these are parat hormone, calcitonin, vitamin D hormone, the thyroid hormones and the sexual hormones - oestrogen in the case of women and testosterone in the case of men. Bones are normally strongest at age 20-25 when the maximum bone mass is achieved. From the age of 35 or so, the bones then begin, slowly but surely, to lose their density. From this point on, the risk of osteoporosis increases.