rotator cuff

Shoulder Pain Slowing You Down? This Easy Self-Assessment Might Tell You The Cause!

“Where you think it is - it ain’t” Ida Rolf

We see hundreds of patients with anterior shoulder pain. And while a lot of the time, the biceps tendon is the culprit (but not always), the real source of the problem is a stiff, or stuck, posterior shoulder!

Here’s a quick screen you can easily perform on your own to assess the range of motion of the primary posterior shoulder muscles - teres minor and infraspinatus.

  1. Lean against a wall (this helps keep your scapula down).

  2. Bring your elbow to shoulder height.

  3. Bend your elbow to 90 degrees and rotate your hand down without letting your shoulder pop forward or your scapula to move.

You SHOULD HAVE about 90 degrees of motion or in other words, be able to almost touch the wall with your hand.

Limited internal rotation ROM leads to compensations with functional activities and can ultimately lead to pain and poor function. Then you come 😢crying to us to fix you.

Take care of it now!

Tired of living with pain?!?


Infraspinatus and Teres Minor


Infraspinatus & Teres Minor


Origin:  Infraspinous fossa (immediately below spine of scapula)

Insertion: Greater tuberosity of the humerus

Innervation: Suprascapular nerve (C4 - C6)

Action:  External rotation

Teres Minor

Origin: Lateral border of the scapula (lateral and inferior to infraspinatus origin)

Insertion: Greater tuberosity of the humerus

Innervation:  Axillary nerve (C5, C6)

Action:  External rotation and weak adduction

Why do I care:  These two external rotators are an integral part of the rotator cuff.  They have the best lever arm to externally rotate the shoulder, allowing the greater tuberosity to rotate away from the coracoid process of the scapula.  This ultimately allows us to reach or push objects over our heads without jamming our rotator cuff tendons between the greater tuberosity and acromion process.  Chronic computer and phone use can cause these muscles to become stretched out.  A stretched out muscle is a weak muscle in most cases.  To prevent this, make sure that you regularly stretch your pecs, subscapularis and anterior shoulders.

Subscapularis - The Armpit Muscle


Origin:  Subscapular fossa (costal or anterior component of the scapula)

Insertion:  Lesser tuberosity of the humerus

Innervation:  Subscapular nerve (C5, C6)

Action:  Internal rotation of the humerus

Why do I care:  Subscapularis is one of the four rotator cuff muscles of your shoulder.  You can touch it if you stick your hand in the opposite arm pit and push on the front of your scapula, or shoulder blade.  This muscle can become shortened with chronic computer use or if placed in a sling for any length of time.  

So? So, if your internal rotators are shortened, you will lack appropriate external rotation of the humerus, which is necessary to get your arm completely overhead without pinching your other rotator cuff tendons in the shoulder joint, which will lead to bursitis, tendonitis and/or rotator cuff tears.