Ageing - muscles bones and joints

Some age-related changes, such as wrinkles and grey hair, are inevitable. It was once thought that changes to muscles, bones and joints were unavoidable too. However, researchers now believe that many of the changes linked with ageing are actually due to inactivity, and that staying active can prevent or even reverse much of the decline and lower the risk of chronic disease.

A large share of disability in later life affects the musculoskeletal system — the muscles, bones and joints. Common problems in older people include:

• Muscle weakness.
• Reduced tolerance to exercise.
• Pain, since any of these conditions can affect how the associated muscles work.

Age-related changes in muscle#

Muscle loses size and strength as we get older, which can contribute to fatigue. This happens because several factors work together:

• Muscle fibres reduce in number and shrink in size.
• Muscle tissue is replaced more slowly, and lost muscle is often replaced with tough, fibrous tissue.
• Changes in the nervous system reduce muscle tone and the ability to contract.

Age-related changes in bone#

Bone is living tissue. As we age, its structure changes and bone tissue is lost. Low bone mass makes bones weaker and puts people at risk of breaks from a sudden bump or fall. Bones become less dense for several reasons:

• An inactive lifestyle leads to bone wastage.
• Bones gradually lose calcium and other minerals.
• Hormonal changes, such as menopause in women and the gradual decline in sex hormones in men, contribute to bone loss and osteoporosis.

Age-related changes in joints#

In a joint, bones do not touch directly. They are cushioned by cartilage that lines the joint (articular cartilage), surrounded by synovial membranes and bathed in a lubricating fluid (synovial fluid).

As you age, joints become stiffer and less flexible because the amount of lubricating fluid decreases and the cartilage becomes thinner. Ligaments also tend to shorten and lose flexibility, adding to the stiffness.

Many of these joint changes are caused by lack of exercise. Movement, and the gentle stress that comes with it, keeps the fluid circulating. Being inactive causes the cartilage to shrink and stiffen, reducing joint mobility.

Common muscle and bone conditions in older age#

• Osteoarthritis — the cartilage within the joint breaks down, causing pain and stiffness.
• Osteoporosis — the bones lose mass and become brittle, so fractures are more likely.
• Osteomalacia — the bones become soft, due to problems with the metabolism of vitamin D.
• Rheumatoid arthritis — inflammation of the joints.

Physical activity can help#

Regular activity can prevent many age-related changes to muscles, bones and joints, and can reverse some of them. It is never too late to start. Research shows that:

• Exercise can make bones stronger and 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.
• Activity in later life may slow the progression of osteoporosis by slowing the loss of bone mineral density.
• Weight-bearing exercise, such as walking or weight training, is the best type for maintaining bone mass. Twisting or rotational movements, where the muscle pulls on the bone, may also be beneficial.
• Even exercising in water, which is not weight-bearing, can increase bone and muscle mass compared with being sedentary.

Stretching is another excellent way to help maintain joint flexibility.

See your doctor#

If you have not exercised for a long time, are elderly, or have a chronic disease such as arthritis, your doctor, physiotherapist or exercise physiologist can help tailor a safe and appropriate exercise program for you.

If you have osteoporosis, you may also be advised to increase your calcium intake, and sometimes medications are needed to treat it.

Key points#

• Muscle loss in later life is caused by several factors, including muscle fibres shrinking and reducing in number.
• Changes in the nervous system reduce muscle tone and the ability to contract.
• Low bone mass makes bones weaker and raises the risk of breaks from a sudden bump or fall.
• Bones become less dense with age for several reasons, including an inactive lifestyle.
• Many age-related changes to joints are caused by lack of exercise.

Where to get help#