Watch the video below to see a demonstration of proper form and technique for the box jump exercise. You can also check out some more hamstring exercise videos or find exercises for other muscle groups.
To perform a set of box jump:
Stand in front of a box (height selected according to your level) with your feet hip width apart.
Start by bending at the hips and knees before explosively extending your hips and legs to jump up and forward toward the box. The goal is to jump high enough that the feet will clear the top of the box when the legs are almost completely extended.
Land on the box as softly as possible by absorbing the impact with your legs. Pause upon landing to ensure that you have control of the motion and are not off balance.
Step down from the box under control. Remember to breathe normally throughout the entire movement.
Repeat steps 1 through 4 until you have completed the desired number of box jump repetitions before resting.
This completes one set of box jump.