The Vertical Jump, is a common and easy to way to measure explosive leg power.
Stand on the ground next to a wall with feet slightly apart. Reach as high as possible while standing, touch and mark the wall. The participant then attempts to jump as high as possible using a two foot take-off. Bend the knees and swing the arms to provide upward drive. Mark the highest jump on the wall. Use a tape measure to record the distance from the starting mark to the highest jump to determine the vertical jump score.