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 can not fall off during the exercise. Stand with your feet slightly wider than shoulder-width, your toes pointed forward or slightly outward facing the end of the barbell so that it is between both feet and directly under your center of gravity.
Squat down by first shifting your hips backwards then downwards to create a hinge-like movement at your knees, as you lower your hips the knees will then start to shift forward slowly, but try to control the amount of forward translation (movement) of the tibia (shinbone). 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, or until your heels begin to lift off the floor, or until your torso begins to round or flex forward. Lift the end of the barbell and firmly grasp it in both hands using a closed grip (thumbs wrapped around the bar). Position the end of the bar directly in front of your chest directly under your chin. Maintain your body position with the spine in neutral (normal-to-flat), shoulders depressed (no shrugging) with scapulae retracted (squeezing shoulder blades together). Keep your chest held up and out, head in line with your spine or slightly extended (raised), heels on the floor, and shoulders over or slightly in front of the bar. Your eyes should be facing forward or slightly upward.
Upward phase: Push your feet into the ground and drive your hips forward to extend your legs and begin the upward phase of the movement by standing up while continuing to hold the end of the barbell in front of your chest. Monitor your feet, ankles and knees; to maintain control of your feet and knees push the floor away from you while keeping your knees aligned over the second toe of each foot as you move up to a standing position.
As you approach a full standing position quickly push through your heels, extending and pushing the hips towards an upright position, begin to press the end of the barbell upwards with both hands continuing to grip the end of the bar, stiffen your core and abdominal muscles (“bracing”) to stabilize your spine.
As the hips and knees reach full extension, continue pushing upward onto your toes at the ankle while pressing the bar overhead into full extension. The movement for the bar should start at the hips, travel through the trunk and continue through the shoulders and arms. Avoid arching your back during the overhead push. Roll up on your toes as you move your legs into triple extension (ankle plantarflexion, knee and hip extension).
Exercise Variation: Increase the velocity or speed of the movement to transition from a strength 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.