Age-Related Musculoskeletal Changes

As we get older our bodies become more fragile, as bone and muscle densities reduce, increasing the likelihood of broken bones and body instability. Movement may become slower, and walking gait may become shorter, more unsteady, and with less swinging of the arms. Older individuals may become tired more easily and perform tasks less energetically, but what are the internal processes that drive these changes in musculoskeletal function?

From around the age of thirty bone mass begins to decrease in both men and women, increasing in rate in women after the onset of menopause. As a result, the risk of bone fractures increases. One common feature of ageing is a gradual shrinking in size. This is due to fluid loss in the spinal disks. Between the vertebral bones in the back are the gel-like cushions which serve to absorb shocks between the vertebrae. With age these discs begin to lose fluid, meaning the spinal bones grow closer together and the spine shrinks. Furthermore, the actual bones begin to lose mineral content, becoming thinner. Being less rigid the spinal column becomes curved, adding to the appearance of height loss.

As with the spinal disks, lubricating fluid between joints may also be lost during the ageing process, reducing protection against cartilage rubbing together and wearing away. As a result, the joints may become stiffer and less flexible, increasing the risk of developing arthritis. As bone wears away the minerals may be deposited around joints and calcify, causing extra joint stiffness.

In tandem with skeletal wear, the muscular system is also affected by age. As bone density decreases around one's 30s so does muscle mass. The result of this muscle loss, known as sarcopenia, is that the muscles are less able to support the bones, and stress on certain joints, such as the knees or back, increases. Deterioration is not universal throughout all types of muscle, and the muscle fibres that contract faster are more susceptible to damage than the slower contracting fibres. This translates into overall slower contraction of the muscles in old age and affects physical mobility, muscular strength, and grip. Around 7% of people over 70 are affected by functional sarcopenia - age-related muscle loss – and this figure increases to around 20% of the elderly over 80. As muscles lose function people become less able to move autonomously and this may translate into the development of muscle contractures, where the muscles shorten and harden.

While it is a natural process of ageing to lose both muscular and skeletal mass, the process can be slowed and prevented to a certain degree by maintaining a healthy lifestyle, with regular exercise to promote strength, balance, and flexibility. Keeping fit can also help the bones to stay strong, to reduce the risk of shrinking or breaking. To further support the maintenance of sturdy bones diet control is crucial, being well-balanced and high in calcium. Particularly women need to be aware of getting enough calcium and vitamin D in their diet as they age to lessen the risk of developing arthritis or osteoporosis.