Home Baseball Content The Truth About Shoulder Impingement: Part 1

The Truth About Shoulder Impingement: Part 1

Written on November 11, 2008 at 4:27 pm, by Eric Cressey

Shoulder Impingement….Yes, We Get It.

Roughly 10-15 times per week, I get emails from folks who claim that they have "shoulder impingement.” Honestly, I roll my eyes the second I read these emails.

Don’t get me wrong: I’m not making light of their pain. It’s just that it drives me crazy when doctors throw this blanket statement out there. I will be completely and 100% clear with the following statement:

Shoulder impingement is a physiological norm. Everyone – regardless of age, activity level, sport of choice, acromion type, gender, you name it – has it.

Don’t reach up to touch that mouse on your computer; you’ll aggravate your impingement and your supraspinatus will explode!

And, don’t scratch that itch on the back of your neck; your impingement will go crazy and your labrum will disintegrate!

Don’t believe me? Check out research from Flatow et al. from 1994.

Yes, this has been out since 1994.

So, the next logical question is: why do some people have pain with impingement while others don’t?

In reality, there are several factors that dictate whether or not someone is in pain, including:

1. Tissue quality – the most “impinged” structures are more likely to break down in older age than they are in earlier years.  Younger individuals can regenerate faster even when overall stress on the tissues is held constant, so how you handle a 50-year-old with "impingement" is going to be somewhat different from how you handle a 15-year-old with "impingement."

2. Degree of elevation – the more one abducts or flexes the humerus, the greater the degree of impingement. This is why folks need to start in a more adducted (arm at side) position early on in rehab.  Those that impinge early in their arc tend to be dealing with subacromial impingement, whereas those who hit it at the absolute top tend to be more AC joint impingement.


3. Acromion type – flat acromions have significantly less contact area with the rotator cuff tendons than hooked or beaked acromions. These structures may change over time due to…

4. Bone Spurs – bone spurs on the underside of the acromion will increase the amount of impingement.

5. Strength of the rotator cuff – the stronger the cuff, the better its ability to depress the humeral head and minimize this impingement

6. Scapular stability – the more stable the scapula, the more likely it is to posteriorly tilt and upwardly rotate effectively when the humerus is raised into the zones of greater impingement. This scapular stability includes adequate length of the downward rotators (pec minor, levator scapulae, and rhomboids) with adequate strength of the upward rotators (lower traps, serratus anterior, upper traps).

7. Thoracic spine mobility – the posture of the thoracic spine dictates the position of the scapulae, which in turn affects impingement as noted in #6.  Assess and Correct is an awesome product for improving thoracic spine mobility - and you can also find some good drills in my recent post, Shoulder Hurts? Start Here.

8. Increased internal rotation – Certain movements that lock the humeral head in internal rotation increase the degree of impingement during dynamic activities. It’s why some people can’t bench press early-on in their rehabilitation programs, yet they can do dumbbell bench presses with a neutral grip pain-free. It’s also the reason why upright rows are a stupid exercise, in my opinion.

9. Breathing patterns – think about what happens when someone has poor diaphragmatic function and becomes a “chest breather:” the shoulders shrug up, and you get extra tightness in the levator scapulae, scalenes, pec minor, and sternocleidomastoid (among other supplemental respiratory muscles). In the process, the degree of impingement can increase.

10. Other issues further down the kinetic chain – I could go on and on about a variety of issues in this regard, but it’s impossible to be exhaustive – so I’ll just give an example. If someone has poor core stability in the sagittal plane that is manifested in an inability to resist the effects of gravity during a push-up, the hips will “sag” to the floor. As this happens, and the upper body remains strong, the scapulae are shifted into an anterior tilt –which increases the amount of impingement on the rotator cuff. So, weakness and/or immobility in other areas can certainly predispose an individual to shoulder problems.

This can also be carried forward to pitchers. We know that shoulder problems are more likely to occur in throwers who have poor lead leg hip internal rotation, as it causes the stride leg to open up early, leaving the arm “trailing behind” where it should be.

Speaking of pitchers, a phrase that has been coined with respect to the “unique” kind of impingement you see in them is “internal impingement.” In next week’s newsletter, I’ll discuss the different kinds of impingement – and why it’s still a cop-out diagnosis for any health care professional to just say you have one or the other rather than tell you explicitly what dysfunctions need to be addressed.

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17 Responses to “The Truth About Shoulder Impingement: Part 1”

  1. Random Friday Thoughts: 10/31/08 | EricCressey.com Says:

    […] 5. I went into quite a bit of detail on why I dislike the term “shoulder impingement” in my newsletter this week. Check it out HERE. […]

  2. Dr. Carla Cupido Says:

    Great article Eric. Love that you covered this topic from so many valid angles! Thanks for the share.

  3. Lisa Says:

    I really enjoyed your article today Eric. As a trainer I find when first meeting a new client and I am taking their health history , one of the first things I hear is that they have some sort of shoulder problem. As you stated in your article, their are many many reasons that may be causing the issues. Thanks for writing about this topic.

  4. Jared Schomburg Says:

    I’ve seen two different articles/blogs now during the last week referring to the upright row as being a poor exercise choice. I would be very interested to read further thoughts you may have on this exercise and why it is not a good exercise selection. Also, how does the upright row compare to the cross cable high row for effectiveness?

  5. Phil Says:

    Thanks Eric,
    Awesome article. sometimes I think if I hear another person tell me their “rotor cup” is torn like it’s a death sentence I’ll go crazy.
    Phil PT

  6. Fraser Dods Says:

    I deal with a wide-ranging patient population that includes flying trapeze artists. These guys spend hours daily hanging from a moving bar – in a position of almost total “impingement”. You’d think that they would have chronic shoulder/impingement problems if any population would. They don’t. Excellent total body strength (in 3 planes) and good spinal flexibility allow them to swing repeatedly without significant problems. Occasional symptoms crop up, and (almost universally) by trigger point release of a knotted upper trapezius – their shoulder symptoms almost immediately resolve. Completely verifies the point(s) Eric makes.

  7. Josh Funk Says:

    Can you please go into more detail about the effect that Hip IR deficit has on the stride leg “opening up” early? I just want to make sure that I am fully understanding the verbage used and how it affects the sequence of the throwing motion. Much appreciated. Thanks for another good one!

  8. John Homer Says:

    In the end, isn’t it all semantics? You have to call it something? Yes, everyone impinges during the day–but respectfully, why get all bent out of shape about it? You listed the different causes for impingement…but that doesn’t make their symptoms resulting from the impingement any less valid. I agree with getting particular about GIRD–because that is a blanket term that is over-treated, but impingement, whether symptomatic or not, is exactly as the name implies. Might as well embrace it.

  9. dev Says:

    I have over the years treated ” impingement syndrome “.
    All great stuff in the article but don’t forget the anterior muscles viz pect major and minor they both rotate the humerus medially and latissimus dorsi together with periscapular muscles which help glide the medial border of the scapula to the thorax .
    Thanks .

  10. Woody Says:

    Alot of great points, lets remember the posterior capsule, imbalance, immobility. Most of your top 10 reasons can be addressed with strength, mobility and flexibility. Avoid any anatomical anomalies and structural causes as best you can.
    Does everybody “impinge” or does everybody move in impingement positions. Do good rhythm and strong force couples, that are balanced, keep one off of the soft tissue that gets inflammed?
    Great food for thought Eric

  11. Andrew Says:

    Thanks for all your great posts. How about an Optimal Shoulder Performance discount?

  12. Jeff Beard Says:

    Thanks Eric. Great point as to why we do not teach the “empty can” anymore and now focus more on external rotation “the Y”. Really addresses opening up the sub-acromial space; thus reducing impingement symptoms — Pain.

  13. Anthony Mychal Says:

    Good stuff Eric. I think the whole breathing issue is big. Something not many thought about long ago could have been the cause of a lot of problems, and yet we\’re just finding out about it. Oh the youth of human performance and fitness in America. I wonder if the overseas legends knew of this?

  14. Emily Falk Says:

    Hey Eric,

    I am an athletic trainer. I am new to taking care of baseball athlete’s and their shoulders. I was using upright rows to help prevent impingement. It sounds like this is a bad idea. I don’t understand exactly why though. Could you explain this to me?

  15. Emily Falk Says:

    I think I was misunderstanding. I have been using rows, not upright rows.

  16. Eric Cressey Says:

    All good, Emily; no worries!

  17. Leonardo Says:

    Eric, would be good if had an online version of optimal shoulder performance! Wainting for this!

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