The treadmill can be used by people of any age. Depending on your requirements, you can have a low or high impact workout. For those who don't have good balance, hand rails provide you with support while walking. The treadmill spans the spectrum of speed for versatility. It'll take you on a leisurely walk, get your heart going with a power walk and turn up the heat with a heart pumping jog or run.
Most treadmills adjust for incline.
Increasing the incline allows you to add intensity to your workout without increasing speed. The treadmill doesn't require you to be too terribly coordinated. You've already mastered the required movement, nothing fancy, just one foot in front of the other. The treadmill works the large muscles in your body for an excellent cardiovascular workout. Then shop around, test them out, and compare various models.