For a true handstand, the exercise is performed free-standing, held in the air.
To prepare the strength until one has built adequate balance, the feet are often placed against a wall, held by a partner, or secured in some other way from falling.
Handstand pushups require significant strength, as well as balance and control if performed free-standing.
The movement can be considered a bodyweight exercise similar to the military press, while the regular push-up is similar to the bench press.
According to one test on competitive male gymnasts in the United States, those competing at Level 4 averaged 3.0 handstand push-ups while those at Level 10 averaged 15.7.