The elasticity of your tendons, ligaments and joints reduces over your lifetime because of changes in the cellular make-up of your tissues. The effects of aging include a gradual decrease in your peak flexibility.
As an individual with unique genes you will differ from others in your potential for flexibility and the rate of possible change. Inactivity, however, plays a much bigger role in your general loss of flexibility over time, and that’s why we say - “Use it or lose it!”
Inactivity at any age will result in you experiencing diminishied flexibility of joints and muscles. Have you ever experienced a fractured leg and spent a long period of time in plaster? This immobilization is necessary to allow your broken bones to knit together. During this time the muscles and joints around the injury are also stabilised.
When you are free to move again you may find that your ankle is no longer flexible because the tendons, muscles and joint capsules around the ankle have lost their elasticity. With stretching exercises you can return to your pre injury range.
If you are older or generally inactive you may feel that you have slowly stiffened up over the years. If you have a further period of passiveness (due to illness or injury) you will experience an increase in your immobility. This can affect your balance and balance reactions and can amplify your risk of falls - which may result in another period of immobilization, and so the cycle continues.
Taking your joints through their full range with daily stretching can help regain your flexibility.