Rotator Cuff Anatomy

Rotator cuff anatomy can not be examined without reference to the shoulder as a whole. The shoulder is a remarkable structure and one of the most involved joints anywhere in the human body. The cuff is an integral part of the shoulder and this is an examination of how they are both constructed.

I want to discuss how the shoulder works and give some detailed information on the complex nature of make up. I will try to answer a few of the common questions such as how is the cuff made up? What is its major purpose? What does each of the muscles actually do?

Shoulder Anatomy

Firstly, however, let's take a look at the shoulder. The shoulder is essentially a ball and socket joint. It is a complex formation of bones, ligaments, muscles and tendons. It provides a great range of motion for your arm. The only downside to this extensive range of motion is a lack of stability. This makes the shoulder joint vulnerable to injury.

Why is the shoulder so potentially unstable? This is due to the physical characteristics of the "ball" and particularly the "socket". The Glenhoid Fossa of the scapula into which is held the humeral head is very shallow, a little like a saucer. As a result, if the humerus is not fitted in snugly and securely. It can, ride up, or move excessively, this is often the case if the cuff is weak.

The majority of people who suffer with shoulder or rotator cuff pain can trace its origins back to a lack of shoulder stability. Indeed, a fair proportion of injuries, such as a rotator cuff tear or impingement, can be blamed on this same instability.

Let's take a detailed look at the shoulder.

The shoulder is effectively made up of three bones, and four muscles. The bones are called the

Scapula
Humerus
Clavicle
Or, in layman's terms
Shoulder blade,
Upper arm bone
Collarbone

There are other features present in the shoulder, such as bursa that enable the tendons to glide smoothly and the acromion but they are not significant features.

Rotator Cuff Anatomy

There are four rotator cuff muscles that connect the shoulder joint to the upper arm bone. Individually they are

Supraspinatus
Infraspinatus
Teres Minor
Subscapularis

It is the contracting and lengthening of these muscles and tendons that help to move your arm.

The muscles have two primary roles within the shoulder, namely, stability and movement. The have to work together to hold the humerus securely, whilst at the same time, enabling the joint to work through its great range of motion. All four of the muscles have a distinct role to play in controlling both movement and stability. That is why an injury or damage to anyone affects the function of the whole shoulder.