Aging changes in the bones, muscles, and joints
Information:
BACKGROUND
Aging changes in posture and gait are as universally recognized as changes in the skin and hair. Elderly people are generally pictured as frail, stooped, and weak.
The skeleton provides support and structure to the body. Joints are the areas where bones come together. They allow the skeleton to be flexible for movement. In a joint, bones do not directly contact each other; instead, they are cushioned by cartilage, membranes, and fluid. Muscles provide the force and strength to move the body. Coordination, although directed by the brain, is affected by changes in the muscles and joints.
Changes in the posture and gait, weakness, and slowed movement are caused by changes in the muscles, joints, and bones.
AGING CHANGES
Bone mass is lost, especially in women after menopause. The bones lose calcium and other minerals.
The trunk becomes shorter. The spine is made up of bones (called vertebrae); between each bone is a gel-like cushion (intervertebral disk). The disks gradually lose fluid, making them thinner. In addition, vertebrae lose some of their mineral content, making each bone also thinner. The spinal column becomes curved and compressed ("packed together"). Bone spurs may also form on the vertebrae, caused by aging and overall use of the spine.
The shoulder blades (scapula) and other bones may become porous (on an X-ray they may look "moth eaten"). The foot arches become less pronounced, contributing (slightly) to height loss. The long bones of the arms and legs, although more brittle because of mineral losses, do not change length. This makes the arms and legs look longer when compared to the body.
The joints become stiffer and less flexible. Fluid in the joints may decrease, and the cartilage may begin to rub. Minerals may deposit in some joints (calcification); this is common in the shoulder. Hip and knee joints may begin to lose structure (degenerative changes). The finger joints lose cartilage and the bones thicken slightly. Finger joint changes are more common in women, and may be hereditary. Some joints, such as the ankle, typically have little change with aging.
Lean body mass decreases, caused in part by loss of muscle tissue (atrophy). The rate and extent of muscle changes seems to be genetically determined. Muscle changes often begin in the 20's in men and the 40's in women.
Lipofuscion (an age-related pigment) and fat are deposited in muscle tissue. The muscle fibers shrink. Muscle tissue is replaced more slowly, and lost muscle tissue may be replaced with a tough fibrous tissue. This is most noticeable in the hands, which may become thin and bony.
Muscle tissue changes, combined with normal aging changes in the nervous system, cause muscles to have reduced tone and contractility. Muscles may become rigid with age, or may lose tone even if exercised regularly.
EFFECT OF CHANGES
Bones become brittle and are broken easier. Height decreases, primarily caused by shortening of the trunk.
Inflammation, pain, stiffness, and deformity result from breakdown of the joint structures. Almost all older people are affected by joint changes, ranging from minor stiffness to severe arthritis.
The posture becomes progressively stooped (bent) and the knees and hips are more flexed. The neck becomes tilted, and the shoulders narrow. The pelvis, on the other hand, becomes wider.
Movement slows and may become limited. The walking pattern (gait) becomes slower and shorter. Walking becomes unsteady, and there is less arm swinging. Fatigue occurs more readily, and overall energy may be reduced.
Strength and endurance change. Loss of muscle mass reduces strength. However, endurance may be enhanced by changes in the muscle fibers. Aging athletes (with healthy hearts and lungs) may find that performance improves in events that require endurance, and decreases slightly in events that require short bursts of high-speed performance.
COMMON PROBLEMS
Osteoporosis is a common problem, especially for older women. Broken bones occur more readily, and compression fractures of the vertebrae can cause pain and reduce mobility.
Muscle weakness contributes to fatigue, weakness, and reduced activity tolerance. Joint problems are extremely common. This may be anything from mild stiffness to debilitating arthritis (see osteoarthritis).
Injury risk is greater because of falls related to gait changes, instability, and loss of balance.
Sometimes, elderly people have reduced reflexes. This is most often caused by changes in the muscles and tendons, rather than changes in the nerves. Decreased knee jerk or ankle jerk are not unexpected. However, some changes (such as a positive Babinski's reflex) are ALWAYS considered abnormal.
Involuntary movements (muscle tremors and fine movements called fasciculations) are more common in the elderly. Inactive or immobile elderly people may experience weakness or abnormal sensations (paresthesias). Restless leg syndrome may occur.
PREVENTION
Exercise is one of the best ways to slow or prevent problems with the muscles, joints, and bones. A moderate exercise program can maintain strength and flexibility. Exercise helps the bones to remain strong. Consult with your health care provider before beginning a new exercise program.
A well-balanced diet with adequate amounts of calcium is important. Women need to be especially careful to get enough calcium as they age. For women, estrogen supplements can also help prevent osteoporosis.
RELATED TOPICS.
aging changes in body shape
aging changes in hormone production
aging changes in organs, tissues, and cells
aging changes in the nervous system
|
|
The information provided herein should not be used for diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Copyright 2000 adam.com, Inc. Any duplication or distribution of the information contained herein is strictly prohibited.
|
|
