Upper and Lower Trapezius Imbalances May Cause Subacromial Impingement

image A new journal article in Physical Therapy in Sport (the journal I recently reviewed) discusses imbalance between upper and lower trapezius muscle activity and the association of subacromial shoulder impingement.

The authors studied the EMG activity of the upper and lower trapezius in subjects with and without subacromial impingement.  Results show that subjects with impingement had a greater ratio of upper to trapezius to lower trapezius than the control group.  There was a large difference in group size (16 impingement subjects, 32 control), which is a limitation, I wonder why they choose to include so many controls.

Asymptomatic subjects had an upper trap (UT) to lower trap (LT) ratio of 1.80 while symptomatic subjects had a ratio of 3.15.  What this means is that the upper trapezius is a little more than 3 times more active than the lower trapezius during scapular plane elevation in patients with subacromial impingement.  This was a statistically significant finding.

Clinical Implications

I have noticed this imbalance in many shoulder patients as well and have always attempted to emphasize lower trapezius strengthening.  This is a part of what goes into my shoulder impingement treatments.

The authors also attempted to demonstrate that taping would then alter this imbalance and showed that upper trapezius activity was reduced after taping (lower trapezius remained the same).  While I commend the authors for attempting to tape and alter this imbalance, I would also state that this imbalance exists for a reason, and while it would be appropriate to try to reduce upper trapezius activity, I tend to focus on the following clinical guidelines:

  • Strengthen the lower trapezius.  This is a common area of weakness in shoulder patients.  See my article on shoulder exercises from JOSPT for some examples of good exercises for the lower trapezius.
  • Educate the patient during exercises to contract the lower trapezius and not the upper trapezius while elevating the arm.  I see this all the time.  I have even seen patients that attempt to “retract” the shoulder during exercises and inadvertently end up with predominantly the upper trapezius.  When you instruct people to “retract” or “pinch their shoulder blades” the emphasis should be back and DOWN.  I bet the majority of people will actually shrug their shoulders back and UP if not instructed properly.  I will work on a video of this to post over the next week or so.
  • Also consider the upper-cross syndrome.  This concept is discussed extensively in Janda and Chaitow’s works.  Inhibition of the lower trap is often associate with inhibition of the deep neck flexors and shortening of the pectoralis muscles, upper trapezius, and levator scapulae.  Attempting to address just one of these deficiencies will likely result in poor outcomes as the global issues have not all be corrected.  When you look at the image below, is it difficult to figure out why this is so prevalent in our population?

image    image

As this type of posture, muscle imbalance, and shoulder pain continue to become more and more prevalent in our society, what else have you done to try to help people like this?  What else have you focused on?

8 replies
  1. Joe brence
    Joe brence says:

    As you know Mike, I am very weary of the word “cause”. I would argue a more defensible explanation would be the altered ratio is an altered action program by a defensive nervous system in these individuals. ie The weakness is a descending inhibition of motor output likely as a means of communication (when pain is not enough). An example of this is bumping your shin on a coffee table. We often experience pain, a reflexive pulling away from the stimulus and short term weakness (all as defense responses). Once the brain determines the table is no longer a threat, you’re feeling like your back to normal. So I would suspect the weakness came secondary so that you quit inducing mechanical deformation (from sai).

  2. Anthony Book SPT
    Anthony Book SPT says:

    What came first the chicken or the egg??

    I am a student physical therapist who suffered a shoulder injury playing flag football. Immediately during my drive home I felt protrusion of my inferior angle into my backrest. Upon further evaluation, I had a slight downward rotation and anterior tilt. Prone planks actually corrected some of the winging so SA wasn’t thought to be involved. Resisted ER caused the whole medial border of my scapula to pull away from my ribcage as did resisted scapular depression!

    It was determined that due to pain/direct injury my middle/lower traps completely lost all input and recovery has been a slow process. I am convinced that for me the trauma caused the compensation.

    Also, Mike – I was not able to elicit contractions to lower traps using Bilateral ER / prone horizontal ER as the JOSPT article suggests. I had to start with maximal isometric contraction of scapular depression/retraction, this might explain the taping performed.

  3. Anonymous
    Anonymous says:

    I really enjoy this post, but I just have one question. It is no surprise to me that the impingement group had a higher ratio of upper trap invlolvement. The problem is trying to distinguish if the impingement stems from the upper traps being dominant and the lower traps being weaker or is the greater ratio that was found due to the upper traps compensating in light of pain/ altered movement due to the impingement? Were the upper traps the cause or the compensation???

  4. Marcello Sarrica PT, DPT, OCS, CSCS
    Marcello Sarrica PT, DPT, OCS, CSCS says:

    I have a 55 yr old patient with severe thoracic kyphosis and adhesive capsulitis, i am implementing everything you guys have talked about for lower traps and T-spine mobility. I doubt that i will ever change or loosen up that 55 yr old T-spine of his. What do you do in that situation?

  5. Anonymous
    Anonymous says:

    In Lewit's masterful book Manipulative Therapy he pointed out that inhibiting the upper trapezius is dependent on reducing thoracic kyphosis. Normally, in the Lewit/Janda teaching one would relax a tight muscle before strengthening a weak partner. However, in the case of the tight upper traps unfortunately it must remain tight to support the neck & shoulder girdles IF a stiff upper thoracic kyphosis is present.

    Thus, he recommended that thoracic extension mobilizations be the 1st treatment to address the upper/lower traps muscle imbalance. The Brugger exercise which Phil suggests is a nice way to address both! Also, proper squat training advice, foam roll exercises, sphinxes, etc can help restore normal thoracic spine posture.

    Lewit also suggested a simple test of the postural-upper trap tightness connection. Have your patient sit in a slump position. Palpate their upper traps. Then have them sit upright in a perch position & re-palpate. You & your pt should immediately sense less upper traps tension w/ an upright posture.

    Craig Liebenson, D.C.
    [email protected]

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