Internal Rotation

In this section, you will learn how to assess your own shoulder.

When we talk about rotation of the shoulder, we think about 3 positions. The way to identify a rotated shoulder is by looking at the alignment of the thumbnail.

Internally Rotated Shoulder

Thumb Inwards = Internal Shoulder Rotation

Shoulder Neutral

Thumb Forwards = Neutral Shoulder

External Shoulder Rotation

Thumb outwards = External Shoulder Rotation

In the western world our lives involve 99% internal shoulder rotation. Typing, driving, eating – all involve internal rotation.   External rotation on the other hard is hardly ever used.

Slouching Shoulder Posture Internal Rotation

Internally Rotated Shoulders. Notice the tension in the neck muscles.

The effect of internal rotation on neck tension.

 If we are talking the classic, constant tension through the top of the shoulders/base of the neck, then we want to take internal rotation very seriously.

When our shoulder is in neutral, the weight of the arm (8 – 14kg) is completely supported by the rib cage. No muscular effort is involved in keeping the arm in place.


When we are internally rotated, the weight of the whole arm moves forward, away from the support of the rib cage. Now gravity is an issue.

Poor Shoulder Posture

In this position the arm becomes heavier, and your body responds. Your trapezius muscle starts working overtime to account for the added weight of the arm.

Slouching Shoulder Posture Internal Rotation

Internal Rotation = Tight, Active Neck Muscles

Neutral Good Shoulder Posture

Neutral Shoulder = Relaxed Neck Muscles

The difference is subtle, but it is there.  Over time, your trapezius gets more and more irritated about being ‘on’ all of the time.   Consider the behaviours that annoy your shoulder/neck. Working at a computer, long drives, anything where you have your hands in front of you in an internally rotated position.

Once you understand the implications of internal rotation – rather than just jump on the rotator cuff bandwagon – lets look deeper at the role of the scapula.