Your ability to balance comes from the inner ear (Vestibular system)
There is a system of canal and organ structures that align with gravity, sense propulsion, motion, rotation
These coordinate with your eyes and muscles and brain
This system always functions, but as you age and move less, your brain becomes less organized with the information
People lose balance easier, slip, fall. This is preventable, but you need to do movement that requires balancing in the first place
This is possibly why tennis seems to improve longevity
It's constant lateral motion, multi directional movement
Keeps the brain young and stimulates neuroplasticity