As we age, several physiological changes occur in the body that can lead to a decrease in flexibility and mobility. Some of these changes include: Loss of muscle mass: As we age, we tend to lose muscle mass, a condition called sarcopenia. This can lead to weaker muscles, which can make it more difficult to move our joints through their full range of motion. Reduced joint lubrication: As we get older, the synovial fluid that lubricates our joints can become thinner and less effective. This can ma