Crane and shoulder joint

Rotator Cuff – What is its job?

Crane and shoulder joint

Over the years I have met many people who have had shoulder issues involving the rotator cuff (RC) and I realised that most people do not really know what the rotator cuff is and what it does.

The rotator cuff is not one muscle, but four small muscles, which attach to the long arm bone and originate at various points within the shoulder girdle. The rotator cuff muscles are important in shoulder movements and in maintaining shoulder joint stability. Unlike the hip, which has a large socket for the hip to sit in, the shoulder joint has been described like a golf ball (head of the arm bone) sitting on a golf tee (small shoulder socket).

These four muscles which form the cuff act to ensure the arm is stable during movement, while the bigger muscles, such as the deltoids, create the large movements of the arm. Consider a large crane. As the arm moves and extends to pick up and put down objects, the base is broad and stable being held down with lots of load. If the base goes, so to does the arm! The shoulder is very much the same.

Crane and shoulder joint


In my opinion there are 2 things that you can do to keep your shoulder working well.

1. Mobilise

An unrestricted joint is able to move through its full range of movement. The opposite is a stiff rigid joint that cannot move well under load and often leads to pain.

 2. Strengthen

When the RC is working well, the articulating bones that form the joint are aligned nicely and movement can occur without concern. The opposite suggests that the bones may be misaligned and allow for less than ideal movement. The result being impingement, clunking, weakness and possible pain.

If you are concerned about the health of your shoulders or experience pain, we recommend you visit a Physiotherapist for a thorough assessment. In the meantime, please book in to see one of our friendly gym floor staff so we can modify your program if need be.

Michael - Gym Floor Supervisor


Gym Floor Supervisor