This exercise combines an explosive jump onto a sturdy box with a controlled step or drop-down, giving you the best of both worlds: power generation and landing control. As you jump up, your calves (alongside glutes, quads and hamstrings) contribute to the take-off. On the descent (especially the drop-down), you practise absorbing force through your ankles, knees and hips. For rehab or performance use, ensure:

• box height is appropriate for your current strength and control

• you land softly with knees aligned, feet flat and torso upright

• you incorporate the drop-down rather than jumping back off the box to emphasise landing-control training.
  Used properly, this movement supports lower leg resilience and coordination, especially helpful after calf or Achilles issues—once basic strength and stability are in place.