How To Perform The Barbell Overhead Press
Place the hooks or cups in the barbell rack just below shoulder height. This way you don't have to go up onto your tippy toes to get the bar out of the rack. Take a shoulder width or slightly outside of shoulder width grip. You can use a thumbed or thumbless grip. Be very careful with a thumbless grip please. Either way, make sure the bar is set very deeply into your hands. If the bar is not deep in your palm, you will likely get extended wrists. Wrist extension will put a lot of pressure onto your wrists and will cause either discomfort or outright pain. And of course this will limit the amount of weight you can use.
Once you have your grip, push your elbows underneath the bar. The bar should be roughly at your collar bones. Break at the knees and do a mini squat to get the bar up and out of the rack. Take two steps back. Your stance should be about shoulder or slightly outside shoulder width.
Pull your chin back as you initiate the concentric. Press the bar toward the ceiling. Once the bar has cleared your head, push your head forward slightly. I like to use the cue, "head through the window." Don't force your head all the way forward as it's unnecessary and might produce unneeded stress on your neck.
You should fully extend your elbows at the top of each rep. If you have hypermobile elbows (many women do) don't hyperextend your elbows at the top. There should be a straight line from your shoulder joint to your fist.
Once you have hit elbow extension, time to begin the concentric. Make sure to control the weight on your way down. As the bar is getting to about head height, pull your chin back again to let the bar pass by your face.
Pay particular attention to cheating on this exercise. This is a strict overhead barbell press. It is very easy when you fatigue to begin using your legs to help you get the bar up. Make sure you keep your lower body from helping at all.
Also pay particular attention to your lumbar spine. It is very common for people to lean back and hyper extend their lower back in order to get the bar all the way overhead. Your nervous system is very smart, and knows that you are stronger pushing horizontally than you are vertically. It will therefore, naturally try to turn the overhead press into a horizontal press. This is a very dangerous position for your lower back. Don't let it happen!