Not everyone is built to press directly overhead. This is more true in standing overhead presses where you're pressing more vertically than, say, seated overhead presses where the bench angle is different.
Exercises like the standing military press aren't inherently bad for your shoulders, and they don't cause shoulder impingement like some would suggest. However, pressing directly overhead can worsen shoulder impingement. This is because it closes down the subacromial space more (area under the acromion) leading to irritation, inflammation, and pain.
Although the likelihood of "closing down" the subacromial space is greater because of other factors involved (muscle imbalances and the shape of your acromion), it's best to avoid pressing directly vertically and with a stiff barbell to manage existing shoulder pain.
So take a seat. Use dumbbells and try either a neutral or pronating grip instead.
Charles Poliquin was a big fan of the pronating-grip dumbbell shoulder press, since it works to take your shoulders through a large range of motion. It also allows your shoulders to move more freely, reducing the risk of wear and tear. Standing and pressing directly overhead can cause low-back pain in some folks too.
Try fixing your butt and back to a seat. Some also find having their feet up or on a wall in front feels more comfortable for their backs too, since you'll have shifted the position of your pelvis and limited lumbar extension.
How to Do It
- To avoid pain pressing directly overhead, try it seated. This will change your pressing angle depending on the inclination of your backrest.
- Use dumbbells and either a neutral (hammer) or pronating grip.
- As you press overhead, do not jam your shoulders back.
- If your shoulders still hurt, then try some landmine presses instead.