Starting Position: Place the end of a standard barbell in a corner so that it will not move unnecessarily. Place a weight on one end of the barbell with a collar so that the weight cannot fall off during the exercise. Stand facing the end of the barbell so that it is between both feet and directly under your center of gravity. Your feet should be slightly wider than shoulder-width with your toes pointed forward or slightly outward.
Squat down by shifting your hips back and down to create a hinge-like movement at your knees. As you lower your hips the knees will then start to shift forward slowly. Try to control excessive forward movement of the shinbones over the toes. Brace your core to keep your trunk stable and spine straight. Continue to lower yourself until your thighs are near, or parallel with the floor. If your heels begin to lift off the floor, or your torso begins to round or flex forward, you have lowered yourself too far. Lift the end of the barbell and firmly grasp it in both hands using a closed grip (thumbs wrapped around the bar and palms facing one another). Position the end of the bar in front of your chest, directly under your chin. Keep the abdominals engaged, the spine in neutral (normal-to-flat), and shoulders pulled down and back (no shrugging). Your chest is lifted and your head is in line with your spine. Heels are on the floor, and shoulders are over or slightly in front of the bar. Your gaze is straight ahead or slightly upward.
Upward phase: Push your feet into the ground and drive your hips forward to straighten your legs. Keep the barbell in front of your chest as you press yourself back to standing. Monitor your feet, ankles and knees. Your knees should align over the second toe of each foot as you move to standing. Do not allow the ankles or feet to roll.
As you approach a full standing position quickly push through your heels, bringing the hips toward an upright position. Begin to press the end of the barbell upward. Brace your core and abdominal muscles to stabilize and protect your spine.
As the hips and knees fully straighten, continue pushing upward onto your toes while pressing the bar overhead. Feel the movement begin at the hips, travel through the trunk and continue through the shoulders and arms. Avoid arching your back during the overhead push. When you press up onto your toes, feel a long line from your ankles all the way through your hips. Your ankles, knees and hips are fully extended.
Exercise Variation: Increase the velocity or speed of the movement to transition from a strength exercise to a power-based exercise.
Start with light resistance then gradually progress this exercise by increasing the weight and increasing the pace of the exercise so that you begin to perform the movement explosively against heavier resistance.
Technique is very important in this lift. Do not progress to explosive movements until you master your technique.