Since antiquity humans have fashioned support devices to hold themselves up when they became sick or injured. Support device use dates back to 2830 BC. A carving on the entrance of an Egyptian tomb depicts a figure leaning on a crutch-like staff.Crutch design has evolved from the basic "T" used by Tiny Tim in A Christmas Carol to lightweight aluminum braces with ice-gripping tips or energy-storing tips that function as shock absorbers and are slip resistant.For lower-limb injuries such as a broken leg, broken ankle, sprained ankle, knee injuries, and other injuries, as well as after surgery on the leg, knee, ankle, or foot, crutches remain useful today to decrease discomfort, reduce recovery time, and assist walking. Often when you get a cast put on your leg or foot you will be required to use crutches for a period of time. Crutches may also be used by amputees, and people with other disabilities that make walking difficult.