The shoulder

Your shoulder is a complicated area because it does several things, which is why when something goes wrong, it can take a while to fix. This is an overall look at how the shoulder works, rather than an anatomy lesson.


Bones and connections

It is important to know a few of the connections that your shoulder muscles make with the bones, so you can get an idea of how complex the shoulder is. There are connections between the shoulder blade (scapula) and collar bone (clavicle); between the shoulder blade, collar bone and top of the arm bone (humerus); between the base of the skull, shoulder blade, collar bone and the trunk of the body.

The shoulder joint isn’t a snug fit like the hip joint. Your hip fits into the hip socket and rarely moves out of the socket, unless there is an injury or your tendons are too loose (hypermobile). The shoulder joint is different because the arm bone is allowed more range of movement and doesn’t fit into the joint as tightly. It also means your shoulder is more prone to injury.

What are the main muscles of the shoulder?

The rotator cuff muscles surround the shoulder, giving it support and allowing it to move. The rotator cuff muscles are the subscapularis, supraspinatus, infraspinatus and teres minor. They connect the shoulder blade to the humerus and keep the head of the humerus in the socket.

When most people think of the shoulder, they think of the back of the shoulder, but the pectoralis major muscle at the front is very important. It helps with support and movement. It attaches to the clavicle, the sternum (breastbone) and to the humerus. Because it attaches to the arm bone, it helps with movement of the arm as well as the shoulder.

The deltoid muscle on the arm is the strongest shoulder muscle. It has three sections. It attaches to the clavicle in the front and at the back, it attaches to the scapula.

The levator scapulae muscle attaches to the neck and goes down to the top of the scapula.

The trapezius (“the traps”) is a large muscle that attaches at the back of the skull, the spine, the clavicle and part of the scapula. Because it covers a large area of the upper back, it is involved in a lot of the movements of the shoulder.

The rhomboid major and minor muscles attach from the spine to the inner border of the scapula, just below the levator scapulae muscles.

The teres major muscle attaches to the lower outside part of the shoulder blade and to the humerus.

The latissimus dorsi muscle (“the lats”) is another large muscle. It runs from the humerus across the back, attaches to the spine and runs down your body to the top of the hips.

What are the most common injuries?

Rotator cuff injury: is when one of the muscles or tendons of the rotator cuff is torn. This can happen from overuse or from an injury.

Impingement: can be painful if there is an injury or inflammation in the rotator cuff muscles. This is because the edge of the scapula (the acromion) presses on the rotator cuff when you lift your arm.

Tendonitis: inflammation of the tendons.

Frozen shoulder: inflammation of the shoulder that limits mobility.

How does your posture affect your shoulders?

Our lifestyles influence how our muscles and joints are held in place. For example, if you do a lot of things in your daily life that involve your shoulders to be angled forward, your muscles will be continually holding your body in that one posture and this leads to you overworking them. Overused muscles tend to get tighter and less flexible, resulting in discomfort and limited range of motion.

What can massage do for tight shoulders?

Massage helps to ease tight muscles by stretching and warming them and encouraging the muscle fibres to relax. The newly relaxed muscles allow the shoulders to be held in a more natural, less tight position. Massage can also help ease pain and discomfort and allow you to move the arms and shoulders more freely.

How often should you have a massage?

You’re an individual and your posture and lifestyle are unique to you. The length of time between massages should be unique as well. Regular massage helps most people whose bodies are affected by less than perfect posture. What does regular mean? That’s up to you. For some people, it’s a monthly massage and for others it’s less often or even more frequent and there are times when you only need one.

What can you do if you can’t afford a massage?

You can usually release the tension in your muscles through a combination of rest, massage, intelligent stretching (e.g. yoga or pilates) or soaking in a warm bath.

You can find free apps online to help you stretch. If you have a tennis ball at home, you can use that to give yourself a massage. Stand against a wall and roll it around the shoulder or lie on the floor and roll it under your body.

If you have an injury or are in pain, see your doctor before you try anything at home. You need a diagnosis and to rule out anything serious.

I hope this has been helpful. As usual, if I’ve made any errors, please contact me.