The overhead press is an exercise from the dawn of weight lifting that has been viciously cast aside in the past ten or so years. In other articles the topics of squatting and other exercises has been covered, but many newer gym rats and personal trainers have decided to disregard this important exercise in favor of machines, band work, and a multitude of other techniques. The fact of the matter is that due to a much more sedentary life with more driving and computer time. For some, just reaching their arms over their heads or jumping has become difficult if not impossible.
In the end it comes down to something called thoracic spine mobility. A lack of t-spine mobility also causes slouching and a loss of mobility in the rotator cuff as. What the overhead (or military) press does is allow for a more flexible thoracic spine and stronger rotator cuff while working the shoulders, upper back, triceps, and upper chest. The t-spine is a driver to the rest of the upper body. If your t-spine is in poor alignment, it throws off everything else down the kinetic chain. It’s one of those movements that just about everyone should do for their health if not for their physique or strength.
Opening up the thoracic spine is important for most workouts, since the t-spine is activated during deadlifts, squats, and all back exercises to some degree. By relaxing this area one could even see better results in terms of pain following workouts, injuries, and even in how much weight one can pull. To do so, refer to this video and this one for how to foam roll the t-spine. It is also possible to roll up and down the whole back slowly to relax the spine before exercise.
That being said, not everyone is able to overhead press. Why not? Because of something called the acromion. The acromion is a bony structure on the top of the shoulder blade that essentially dictates how much room one’s rotator cuff has to “breath”. There are three types of acromion that are split pretty evenly in thirds across the population: Type I, II, and III.
Type I individuals are those who have a considerable amount of room and need not worry about not being able to overhead press
Type II people basically have a 50/50 chance of not being able to overhead press depending on how strong the curvature is (see diagram).
Type III individuals are the unfortunate third of the population that will almost always have trouble overhead pressing because of their rotator cuff.
A key thing to note is that one should not assume they are Type III right off the bat because the military press feels awkward or downright difficult at first. It is astounding how little people actually press things above their heads, which is why most should start with just the bar to get a feel for the movement. One should not expect to be heaving up massive 200+ lb loads upon first starting; this is a compound lift that works many smaller muscles in the upper body. Don’t go too heavy too fast: it’s the biggest mistake a prospective lifter can make when starting out, especially with this exercise. One last thing to note is that athletes don’t need a barbell to overhead press. It is possible to use dumbbells, kettlebells, and even bands to complete the exercise, although the barbell version is generally considered the best.