A demi-plié provides both spring and momentum in allegro work, making fast steps easier, jumps higher, and landings softer. Demi-plié must be used at the beginning and end of all springing and allegro steps, including glissades. A well-executed glissade must be completed in one count, making certain to put the same energy in stretching the closing foot as in the leading foot.
Demi-plié also facilitates the transfer of weight in a piqué. Before stepping onto a piqué (or posé), the dancer should demi-plié on the supporting leg to enable a good push off onto the stepping leg. This places the dancer solidly on the stepping leg on pointe or demi-pointe.