This test is designed to measure your explosive leg lower. All you need is a high wall, such as the outside of a building, and a bit of room so you can jump and land safely.
Start by standing side on to a wall and reach up as high as you can with the hand closest to the wall. Make note of how high you can reach. This is called the standing reach height. Then stand a little away from the wall, and jump high as possible using both arms and legs to assist in projecting the body upwards. Attempt to touch the wall at the highest point of the jump. Make note of where you touched the wall at the height of the jump. Measure the distance between the standing reach height and the maximum jump height, and that is your result.
You can assist in recording your score by holding a piece of chalk in your had and using it to mark the wall. If the wall already has horizontal lines, such as a brick wall, it will be easier to mark your jump height. Have as many attempts as you need to get the best possible score. Practice your technique, as the jump height can be affected by how much you bend your knees before jumping, and the effective use of the arms.