Can “not-shrugging” in the Press contribute to shoulder impingement?

[Abel Jauwena]

Greetings everyone.

I just want to ask whether not shrugging in the Press can contribute to shoulder impingement (i.e. the head of the humerus hitting the bony protrusion of the scapula).

I just finished a set of high-rep Presses today (I know, I didn’t do fahves) and felt an impinging sensation in my left shoulder at lockout. Granted, I forgot to shrug at the top (or had a “weak,” incomplete shrug) at the later reps.

As far as I understand, when we move our arms overhead (prior to the shrug), the scapulae already freely rotate upwards, so impingement isn’t really possible. The shrug at the top serves to reinforce their upward rotation and elevation, but it isn’t “necessary” per se from an injury prevention standpoint.

However, my experience today suggests otherwise. Could it probably be due to the way my acromion is structured (i.e. having a more pronounced protrusion)?

Sorry for the wall-of-texty post. Thank you, I appreciate you guys’ inputs!

[Mark Rippetoe]

I just want to ask whether not shrugging in the Press can contribute to shoulder impingement (i.e. the head of the humerus hitting the bony protrusion of the scapula).

Yes, it does. Shrug the top of the press.

[Abel Jauwena]

Thanks for the reply, Rip.

So it is possible to impinge your shoulder in an incorrectly performed press. I'll pay very close attention to shrugging at the top from now on. I'm honestly kind of paranoid of not shrugging after knowing that fact...

Also, if I may ask another question, is the popular belief that presses are "bad for the shoulders" caused by people performing the press incorrectly, i.e. not shrugging at the top?

[Jr_Geezer]

Yes, it does. Shrug the top of the press.

I'm missing some understanding on this. At the top of the press, before the shrug, there is a possibility of impingement, correct? But by increasing the ROM with a shrug, the possibility of impingement is reduced or eliminated. So is the temporary impingement before the shrug not a problem? I mean the shrug can't have any effect on what comes before it, right? And if it relieves the impingement on the way up, does the impingement re-occur on the way down? What exactly is going on at the top, before and after the shrug?
Thanks.

[Mark Rippetoe]

The traps rotate the scapulae medially and superiorly as the bar goes up, not just at the top. The shrug at the top is a cue to finish the movement.

[Jr_Geezer]

The traps rotate the scapulae medially and superiorly as the bar goes up, not just at the top. The shrug at the top is a cue to finish the movement.

I'm still missing something. Where then does the impingement occur and how does the shrug, which is a cue to finish the movement, prevent that impingement? Are there other parts of the press technique that prevent the problem, such as elbows in front of the bar (as opposed to flaring out)? It's been a while since I've read the press chapter of the blue book, perhaps I should revisit.

[Mark Rippetoe]

Perhaps that would be helpful.

[Abel Jauwena]

If I may voice my opinion, the way I understand it is this (and please correct me if I'm wrong):

There is very, very little-to-no possibility for impingement as the arm goes up from the bottom position. As you raise your humeri, your scapulae, and thus the socket of the AC joint, also rotate to prevent your humeri from hitting the "roof." In other words, the roof is also rotating upward.

However, at the very top of the movement without a shrug, the scapulae may already reach its end ROM in terms of rotation (at least in some people). Well, you still need to raise your humerus that extra inch to lock the barbell out. When you don't shrug, the scapulae (and thus the roof) stays in place while your humeri continually moves upward. So, it increases the possibility that they hit that roof and impinge the soft tissues beneath that roof. If I'm not mistaken, this phenomenon is also more likely to occur with a wider grip, thought I'm still unsure why.

The shrug therefore serves to provide that extra bit of scapular rotation to accommodate your humeri continually moving upward. The traps pull the scapulae medially and superiorly, and the roof is therefore raised too.

Keep in mind that this is just my amateur-level analysis, and that my pain experience is likely caused by a whole bunch of factors aside from forgetting to shrug (for example, already expecting/anticipating the pain to occur before performing the movement).

[Mark Rippetoe]

So, it increases the possibility that they hit that roof and impinge the soft tissues beneath that roof. If I'm not mistaken, this phenomenon is also more likely to occur with a wider grip, thought I'm still unsure why.

Because the angle produced by the wide grip prevents the shrug from rotating the scapulae fully upward and medial.

[Abel Jauwena]

Hi Rip. This thought just crossed my head and I wanted to clarify it with you.

So I pressed today and moved my grip 1 finger width narrower. In my previous (wider) grip, my forearms are still vertical, but my humeri are slightly angled to the side. With my new (narrower) grip, my humeri are naturally more forward to keep the forearms vertical.

Then, I made extra effort to keep my elbows forward in the ascent and to “flare the elbows late.”

Well, I did not feel any impinging sensation whatsoever. Perhaps keeping my elbows from flaring early prevented me from abducting AND internally rotating my humeri early, i.e. during the ROM prior to them being at 90 degrees to the floor? I know from your podcast that that position is a surefire way to impinge the soft tissue around the shoulder.

Also, is this a form of the “incorrectly performed press” that is prevalent among the average gym goer, because of which the press gets a bad reputation?

Curious to hear your thoughts on this. Thanks by the way.