Our bodies get stiffer with age primarily due to several interconnected physiological changes. As we age, the lubricating fluid in our joints decreases, leading to less smooth joint movement and stiffness. Additionally, the cartilage that cushions joints wears down, causing reduced cushioning and more resistance during movement. Muscles, tendons, and ligaments also lose elasticity and become less flexible, which contributes to stiffness. Muscle mass and strength decline due to sarcopenia (age-related muscle loss), and muscle fibers can be replaced by tougher, fibrous tissue that is less pliable. Reduced physical activity with age further exacerbates these effects by weakening muscles and reducing joint mobility. Blood circulation changes and age-related conditions like osteoarthritis also contribute to stiffness. The overall increase in connective tissue stiffness and changes in the muscle- tendon complex make movements require more effort and limit the range of motion.
Key factors include:
- Decreased joint lubrication (synovial fluid) that normally eases joint movement.
- Thinning and degradation of cartilage in joints reducing cushioning.
- Loss of muscle mass and strength (sarcopenia) combined with replacement by less elastic fibrous tissue.
- Reduced elasticity of tendons, ligaments, and muscles.
- Lower levels of physical activity, causing disuse atrophy and stiffness.
- Possible changes in connective tissue and extracellular matrix increasing muscle stiffness.
- Age-related diseases like osteoarthritis and rheumatoid arthritis causing joint inflammation and pain.
Maintaining movement and physical activity is essential to minimize stiffness and preserve flexibility as one ages.
