What exercise requires that the knees always stay in line with the toes throughout the jumping phases of takeoff and landing?

The correct answer is - power step-ups.

Explanation:

Power step up is an exercise that involves an individual to stand upright and lift ur chest and tuck chin in. Put one leg on box or step and forcefully push that leg into the air and put the leg softly on the box or step and again push this leg now in air forcefully and softly put another leg on the box, repeat this again and again.

This exercise helps to keep the knee in line with the toe through the jumping of landing and take off.

Thus, the correct answer is - power step-ups.

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.