Seated Box Jump
The seated box jump is a variation of the box jump that eliminates the assistance of a countermovement.
Sit on a small box in front of a taller box. With as little rocking of the body as possible, jump directly from the seated position up onto the other box. Rocking can be best minimized by leaning forward as needed to feel balanced on the feet and using this as the starting position after a static hold here. The seated box jump can also be done by lifting the feet, then planting them aggressively and immediately driving up into the jump as a low-level variation of a depth jump.
The seated box jump is a way to train jumping with concentric-only motion—by removing a countermovement, the assistance of elasticity is eliminated.
Seated box jumps should be performed at the end of a training session with 3-6 sets of 3-5 reps.