Age-Related Changes on the Skeletal System and Joints
The slower movement, weakness, and altered physi-cal appearance are a result of changes in the muscu-loskeletal system.
With age, there is a decrease in height as a result of the shortening of the vertebral column. The inter-vertebral disks and the vertebrae decrease in height. The continued growth of nose and ear cartilage makes them larger. Subcutaneous fat tends to be re-distributed with more in the abdomen and hips and less in the extremities. This redistribution makes the bony landmarks more prominent with deepening hollows in the axilla, shoulders, ribs, and around the eyes.
The ground substance, in relation to the collagen fibers, is reduced in the tissue, resulting in stiffness, less ability to deform to stress, and reduced nutritional status. Changes in the vertebral column, stiff-ening of the ligaments and joints, and hardening of the tendons result in mild flexion of the vertebrae, hips, knees, elbows, wrists, and neck.
With age, bone formation is slowed in relation to absorption. This results in loss of bone mass and weakening of the structure. Certain changes that occur are also a result of disuse. The loss is greater in women as the estrogen levels drop. Trabecular bone (the net-work found in the medullary cavity) loss is greater than cortical bone and areas with a higher ratio of tra-becular bone, such as the head of femur, radius, and vertebral bodies, are more prone for fractures.
The production of synovial fluid in the joints de-creases with age. The articular cartilages become thinner. Because joints are also affected by genetic makeup and wear and tear, the changes observed with age vary individually. Osteoarthritis is associ-ated with increasing age.