Everything you need to know about your shoulder

January 20 2022
Everything you need to know about your shoulder

Everything you need to know about your Shoulder

The bones of the shoulder

  • The shoulder is made up of 3 bones; the humerus, clavicle (collar bone) and the scapula (shoulder blade).
  • Joints are where 2 or more bones meet. The shoulder joint is made up of 4 joints; the glenohumeral joint, acromioclavicular joint, sternoclavicular joint and scapulothoracic joint.
  • Glenohumeral joint – This is commonly considered the main joint in the shoulder. It is made from the top/head of the humerus and the rounded socket of the shoulder blade. It creates a ball and socket joint and allows circular movements of the shoulder.
  • Acromioclavicular joint – This joint is located between the clavicle (collar bone) and the acromion, which is located at the top of the shoulder blade. This joint allows lifting the arm over the head.
  • Sternoclavicular joint – This joint is located between the collar bone (clavicle) and the chest bone (sternum). This joint is involved in shrugging, talking the arm behind the body and raising the arm overhead.
  • Scapulothoracic joint – this joint is located where the shoulder blade (scapula) glides against the rib cage.



The shoulder joint is essential in everyday activities, as it is involved in all arm movements. It is vital that our shoulder is functioning well to allow us to carry out these tasks pain free.

As well as the bones and joints, the shoulder contains a soft tissue network of muscles, tendons and ligaments. These soft tissue structures are often involved in injuries of the shoulder.

The muscles of the shoulder

The main group of muscles within the shoulder is called the rotator cuff. This cuff is made up of 4 muscles and all of them originate from the shoulder blade (scapula) and attach onto the humerus (upper arm bone). They are all involved in stabilising the glenohumeral joint. The 4 muscles are:

  1. Supraspinatus – this is the smallest of the 4 muscles and is located at the top of the shoulder. This muscle is involved in raising the arm out to the side.
  2. Infraspinatus – this muscle is located at the back of the shoulder blade and is a thick triangular muscle. This muscle is involved in rotating the arm away from the body.
  3. Teres minor – This muscle is again located at the back of the shoulder blade, under the infraspinatus. This muscle is involved in bring the arm towards the body and taking the arm behind the body
  4. Subscapularis – This muscle is located on the front of the shoulder blade, the muscle is large and triangular shaped. This muscle is involved in rotating the arm towards the body.

As well as the rotator cuff muscles, there are a range of other muscles around the shoulder region. These other muscles can also be involved with injuries of the shoulder.

  • Deltoid – This is the muscle that sits over the glenohumeral joint. It is responsible for a lot of movements of the arm, especially raising the arm and assisting the muscles in the chest.
  • Biceps – This muscle is located at the front of the upper arm. This muscle is involved in bending the elbow and rotating the forearm
  • Triceps – This muscle is located on the back of the upper arm and is involved in straightening the elbow
  • Pectoralis major – this is our chest muscle and is attached to the upper arm at the level of the shoulder. The muscle is involved in bring the arm forward
  • Latissimus Dorsi – This is a large muscle that is located on the back and attaches onto the upper arm at the level of the shoulder. This muscle is involved in  moving the arm down and away from the body.

Of these accessory muscles, the tendon of the biceps muscle is most susceptible to becoming injured. However, this usually responds very well to conservative care and more invasive care is often not needed.


On top of all these muscles, there are also a number of other soft tissue structures surrounding the shoulder joint. These include; ligaments, the labrum and bursa.


Ligaments are fibrous bands of connective tissue and their role is to connect bone to bone and stabilise joints. There is a network of ligaments around the shoulder that provide the shoulder joints with stability.


The labrum is another connective tissue structure within the shoulder complex. This structure is located deep within the glenohumeral joint cavity. The role of the labrum is to provide stability to the glenohumeral joint and to allow smooth movement to occur within the joint. Like all other structures within the shoulder, the labrum can also be damaged. It can be torn through a traumatic injury or through over use.


Bursa are small fluid filled sacs that are located all over the body at points where muscles, tendons and ligaments are prone to rubbing together. The role of these structures is to reduce friction. Bursa can become irritated or inflamed with overuse or unusual pressure over the area. The most suspectable bursa to injury in the shoulder joint is the sub-acromial bursa.

Shoulder problems and injuries

There are many different conditions that can affect the shoulder, from fracturing the bones that make up the shoulder to damaging the soft tissue around the shoulder complex.

Some of the most common conditions affecting the shoulder are:

  • Shoulder dislocation
  • Rotator cuff tear
  • Fracture
  • Impingement
  • Bursitis
  • Frozen shoulder
  • Cartilage tears

Shoulder dislocations

This is when the arm bone has come out of the socket, this is most likely due to a trauma to the shoulder. It will result in the shoulder feeling very weak and painful. If this does occur, you should go to A&E and do not try to put it back in yourself. This is because soft tissue structures around the shoulder joint can become damaged and imaging such as X-ray may be required.

Rotator cuff tears

These can be caused by over-use over the shoulder, especially in over-head positions, or it can be caused by a fall.  As we get older this group of muscles become more prone to injury. Symptoms can include pain when lifting the arm and it can be painful to lie on at night.


This is when one of the bones within the shoulder complex has cracked or broken.  Like the dislocation, this is usually due to a trauma or fall. The pain in the area will be very intense and if the collar bone is broken, your shoulder will sag and you will be unable to lift your arm. You should go to A&E.

Frozen shoulder

This is when the movement of your shoulder becomes severely limited due to adhesions within the capsule of the shoulder joint. This condition is often very painful and is more common over the age of 40. The cause is not known but it is known to be more common in individuals with diabetes.


This occurs when a tendon of the rotator cuff muscle gets pinched by the bones in the shoulder joint. This pinching can result in pain and swelling. It is more common in individuals that do repetitive movements with their arm over their head.


This is when the bursa become swollen and irritated. This can be caused by irritation by doing the same movement repeatedly or by a fall. It can result in pain when moving the shoulder.

How chiropractic can help with shoulder pain.

When first seeing a chiropractor about your shoulder pain, they will ask you a number of questions about your shoulder pain and then carry out a detailed physical exam.

Once the chiropractor has identified what they believe to be the problem, they will explain to you what they think is going on and how they can help.

First the chiropractor will give some advice about what you can do yourself to help the pain, this may include:

  • Stay active and gently move your shoulder, do not stop using your shoulder completely.
  • Stand up straight with your shoulders down and gently back
  • Sit with a cushion behind your lower back
  • Rest your arm on a cushion in your lap
  • Use pain relief so you can keep moving – try painkillers like paracetamol and ibuprofen and heat or cold packs

Type of treatment the chiropractor will provide may include:

  • Soft tissue work to the muscles surrounding the shoulder joint and upper back. Including massage, release techniques and stretches
  • Mobilisation of the joints within the shoulder
  • Adjustments of the neck or upper back
  • Specific exercises to strengthen a specific area of the shoulder that may be weak

Research has shown a combination of these treatment methods helps to reduce pain and improve function in many types of shoulder injuries.

When to contact your GP or the hospital

  • The pain is sudden or very severe
  • You cannot move your arm
  • Your arm or shoulder has changed shape or is badly swollen
  • You have pins and needles that do not go away
  • There is no feeling in your arm or shoulder
  • Your arm or shoulder is hot or cold to the touch
  • The pain started after an injury or accident, like a fall
  • You feel feverish or unwell

How can you help yourself and prevent the onset of shoulder pain.

  • Be aware of your posture – when sitting don’t let yourself slouch forward, keep your shoulders back, pull your shoulder blades back and down and tuck your chin slightly in.
  • Take care in activities that involve reaching over head or lifting heavy objects
  • When lifting ensure you lift with the correct technique.