Strength, endurance, and flexibility are the key attributes that define childhood and youth. As people get on in years, these attributes start to go away with every passing year. Finally, the ability to move up and about is gone, rendering people immobile and confined to one single space. This can be frustrating and upsetting for many, especially those who might have enjoyed a few more years of mobility. Still, due to injuries and physical infirmities, their movement has been restricted. The loss of mobility in old age can be terrible. One of the biggest problems they face is not getting about between floors.