A joint also called an articulation, is any place where adjacent bones come together (articulate with each other) to form a connection. The joint allows the bones to move freely but within controlled limits.
There are various types of joints in the body but among them, the synovial joints are the most common joint.
A key structural characteristic for a synovial joint is its joint cavity. This fluid-filled space is the site at which the articulating surfaces of the bones come into contact with each other. This gives the bones of a synovial joint the ability to move smoothly against each other, allowing for increased joint mobility.
Some joints, such as the knee, elbow, and shoulder, are self-lubricating, almost frictionless, and are able to withstand compression and maintain heavy loads while still executing smooth and precise movements. Other joints such as sutures between the bones of the skull permit very little movement (only during birth) in order to protect the brain and the sense organs.
In a joint, bones do not directly come into contact with each other. They are cushioned by cartilage that lines your joints (articular cartilage), synovial membranes around the joint and a lubricating fluid inside your joints (synovial fluid).
Muscles provide the force and strength to move the body. Coordination is directed by the brain but is affected by changes in the muscles and joints. Changes in the muscles, joints, and bones affect the posture and walk, and lead to weakness and slowed movement.
AGING CHANGES ON JOINTS AND MUSCLES
From about age 30, the density of bones begins to diminish in men and women. This loss of bone density accelerates in women after menopause. As a result, bones become more fragile and are more likely to break, especially in old age.
As people age, their joints are affected by changes in cartilage and in connective tissue. The cartilage inside a joint becomes thinner, and components of the cartilage (the proteoglycans—substances that help provide the cartilage’s resilience) become altered, which may make the joint less resilient and more susceptible to damage. Thus, in some people, the surfaces of the joint do not slide as well over each other as they used to. This process may lead to osteoarthritis or osteoarthrosis. Additionally, joints become stiffer because the connective tissue within ligaments and tendons becomes more rigid and brittle. This change also limits the range of motion of joints.
Loss of muscle (sarcopenia) is a process that starts around age 30 and progresses throughout life. In this process, the amount of muscle tissue and the number and size of muscle fibres gradually decrease. The result of sarcopenia is a gradual loss of muscle mass and muscle strength. This mild loss of muscle strength places increased stress on certain joints (such as the knees) and may predispose a person to arthritis or falling.
Symptoms of osteoarthritis can include:
- Pain• stiffness• a grating or grinding sensation (crepitus) when the joint moves• swelling (either hard or soft) • not being able to use the affected
Joint normally, which can make it difficult to do certain activities
(For example climbing stairs).
Exercise is one of the best ways to slow or prevent problems with the muscles, joints, and bones. A moderate exercise program can help you maintain strength, balance, and flexibility. Exercise helps the bones stay strong.
A Harvard Alumni Study has published a report that a caloric expenditure of >2000 kcal/day associated with 25% reduction in mortality, they even suggested that physical activity levels must be maintained THROUGHOUT life
Research shows that:
- Exercise can make bones stronger and help slow the rate of bone loss.
- Older people can increase muscle mass and strength through muscle-strengthening activities.
- Balance and coordination exercises, such as tai chi, can help reduce the risk of falls.
- Physical activity in later life may delay the progression of osteoporosis as it slows down the rate at which bone mineral density is reduced.
- Weight-bearing exercise, such as walking or weight training, is the best type of exercise for maintenance of bone mass. There is a suggestion that twisting or rotational movements, where the muscle attachments pull on the bone, are also beneficial.
- Older people who exercise in water (which is not weight bearing) may still experience increases in bone and muscle mass compared to sedentary older people.
Aerobic exercise is any exercise that increases your pulse rate and makes you short of breath (for example a brisk walk, swimming or using an exercise bike). Regular aerobic exercise should help you sleep better, is good for your general health and well-being, and can also reduce pain by raising the levels of pain-relieving hormones called endorphins.
- Stretching is another excellent way to help maintain joint flexibility.
See your doctor before you start any new physical activity program. If you haven’t exercised for a long time, are elderly or have a chronic disease (such as arthritis), your doctor, physiotherapist or exercise physiologist can help tailor an appropriate and safe exercise program for you.
Older adults are the fastest-growing segment of the population
- As the older adult population increases in number, there is considerable impact on health care and economic aspects of society
- Observational studies suggest that physical activity may increase the quantity and quality of life
It’s never too late to start living an active lifestyle and enjoying the benefits.