Kinesiology THURSDAY - Rhomboid v. Infraspinatus (Tug-o-War Series)

Illustration of upper back muscles anatomy.

The infraspinatus is commonly considered an external rotator of the humerus, but trigger points noted near the inferior angle of the scapula demonstrate its capacity to upwardly rotate the scapula. The rhomboid is a downward rotator of the scapula and acts as a stabilizing synergist for the infraspinatus.

Rhomboid insufficiency may occur in the presence of a trigger point in the infraspinatus. And infraspinatus trigger points are common with rotator cuff impingement. This arrangement may also be observed in someone who is lacking ipsilateral thoracic rotation.

Three tests to know if this is the case:

Palpate for infraspinatus trigger point in the infraspinous fossa near the inferior angle
Have patient perform prone horizontal abduction of the shoulder. They SHOULD feel a strong rhomboid (midback) contraction. If they feel anterior (front) shoulder pain, then the infraspinatus is overriding the rhomboid.
Ask them to reach overhead. Do they feel a jam/pinch at the top of their shoulder? If so, this abnormal tug-o-war could be present.

Here’s some manual therapy fixes:

Perform deep trigger point massage to the infraspinatus trigger point.
Counterstrain infraspinatus
- With patient in relaxed seated position, palpate for tender point. The most common is the one on the inferior angle
- Passively extend and externally rotate the shoulder until tender point is at least 70% eliminated
- Hold position for 90 seconds
- Passively return to neutral and recheck tender point

Tender point locations and counterstrain position on back

Once you’ve released the infraspinatus, it’s time to activate the rhomboid. One of the best ways to do this is by performing a row with the arm abducted 90˚.

Dumbbell rhomboid row
Seated cable row (pulling towards chest)
Standing mid pulley row (make sure you pull with our arm abducted to 90˚)

Man demonstrating resistance band arm exercises

Why does this matter?

Don’t get stuck in a rut always thinking the infraspinatus is weak in your shoulder impingement patients. Often it is tight (trigger point), causing inhibition of the rhomboid. Consider the rhomboid v. infraspinatus tug-o-war.

Because nobody has time to be in pain.

Until next time…