The fundamentals of the shoulder
 – by Kim Hart
This article will focus on the shoulder; how it works and why it is one of the most commonly injured body parts. Hopefully it can help you better prepare for exercise and prevent some activity and sport related injuries. This article will provide an introduction into what makes up the shoulder joint and how it works.
We use the shoulder to do so many simple tasks as well as complicated manoeuvrers such as climbing and throwing a ball. It is also the most unstable joint in the body. This is why it is very important to keep the surrounding muscles healthy and strong to prevent any injuries.
The shoulder is a complex joint, but is actually only composed of 3 bones which make it quite unique from the other major joints of the body. This uniqueness makes it very vulnerable to injury which is an area we’ll touch on later. The three bones that encompass the shoulder are the clavicle (collar bone), the scapula (shoulder blade) and the humerus (upper arm). The connection between the arm and shoulder blade is known as a ball and socket joint, the only difference being that in the shoulder, the ball is too large for the socket. This is illustrated in the diagram to the left which shows the large head of the humerus and the shallow depression of the scapula that it is supposed to sit in.
This disparity is often the big cause of injuries in the shoulder, with the ball slipping out of the socket far too often. A way to prevent this is to strengthen up the muscles that attach to these three shoulder bones to help keep them supported and injury free.
Exercise physiologists and fitness professionals often use the term “rotator cuff” when directing strength programs and stress its importance in shoulder stability. This is all well and good, but what does it actually mean? The rotator cuff is actually a group of muscles and tendons that act to stabilise the shoulder. The four muscles in the rotator cuff are the infraspinatus, supraspinatus, subscapularis and teres minor. These muscles snugly fit around the shoulder and act like a glove to hold the shallow ball and socket joint in place.
Whilst the rotator cuff is of great importance structurally, it is quite easy to injure its muscles, so it is important to be careful not to over do it! If you do feel a bit of a pinch in your shoulder after lifting some weights, be sure to apply the RICE protocol (rest, ice, compression, elevation) and see a health care professional if it persists, as rotator cuff injuries can progress to very serious quite quickly.
The next article will focus on exercises that are used to strengthen the shoulder joint and rotator cuff and how you can incorporate them
into your workout.