Aching pain in shoulder blade

Amy Hume and Andrew Armstrong

Musculoskeletal physiotherapists

2 April 2026

Shoulder pain is a common problem for many people. 1 in 100 people will present to primary care with a new shoulder pain annually¹ and nearly 70% of people will experience shoulder pain in their lifetime.¹ There are various conditions which can range in nature and severity that can be the cause of this pain.

We explore some of these common causes and look at the potential treatment options for each.

Rotator cuff related shoulder pain

The rotator cuff is a group of four deep muscles that originate from the shoulder blade and attach, through their tendons, to the upper arm bone. The function of these muscles is to assist in moving the arm and stabilising the shoulder’s ball and socket joint.

The shoulder joint requires synchronised movement but due to the location of the rotator cuff in the joint, it can be the cause of shoulder pain.

What is rotator cuff related shoulder pain?

Common terms used to describe shoulder conditions include:

Tendinopathy – reactivity of the rotator cuff tendons
Bursitis – inflammation of the friction reducing structures
Impingement – pinching of structures in the shoulder.

However, shoulder pain can be caused by multiple factors that these alone can’t truly explain. For this reason, the term ‘rotator cuff related shoulder pain’ captures all these terms and can help medical professionals when assessing the problem and allow them to take a more holistic approach to care.

How is it assessed?

Doctors and physiotherapists would assess your shoulder through a combination of questions and movement assessments.

For example, one common movement pattern is known as a ‘painful arc’. This is where the shoulder is most painful midway (60-120°) through moving the shoulder to the side and up.

Why does it happen?

Rotator cuff related shoulder pain typically comes from an increase in activities or a sudden movement but can also be influenced by age-related changes in shoulder structure.

This can cause:

irritation of the rotator cuff tendons,
or tears in the rotator cuff.

The pain from this can cause weakness and disrupt the way the shoulder is moving and lead to ongoing pain. If managed early through the right movements, these conditions will generally settle down on their own.

If the disrupted movement pattern or weakness continues, the pain may stay the same for months or can even get worse.

It is best to speak to your doctor or a physiotherapist if symptoms aren’t improving.

Frozen shoulder

Frozen shoulder is a condition where the shoulder becomes painful, stiff, and difficult to move.² For most people symptoms tend to get better/resolve within 18 to 24 months, however symptoms can be managed with various treatments.

Frozen shoulder most commonly affects people aged between 40-60 and occurs more often in women than men.³ People with diabetes and thyroid conditions also have an increased chance of getting frozen shoulder.³

Causes of frozen shoulder

It is not always clear why some people develop a frozen shoulder – at times there are no underlying causes which is called primary (or idiopathic) frozen shoulder.

If there’s an underlying cause, this is called secondary frozen shoulder. Possible causes include:

Shoulder injury i.e. rotator cuff injury.
Immobilisation of the shoulder joint for a prolonged period i.e. following a fracture or shoulder surgery.
Certain medical conditions for example diabetes, under or overactive thyroid or Parkinson’s disease.³

Frozen shoulder symptoms

Typically the two main symptoms are pain and stiffness, and the pain develops in three stages:

1) Freezing – During this stage, pain is the most dominant symptom and gradually worsens overtime. As the pain worsens, the movement within the shoulder becomes restricted. This stage typically lasts between 2 to 9 months.

2) Frozen – Pain gradually improves during this stage, with the main limiting factor being shoulder stiffness. This stiffness restricts movement, making daily tasks difficult. This can last for anything from 4 to 12 months.

3) Thawing – Shoulder movements slowly improve during this stage. Completely return to normal / close to normal movements and strength can take anywhere between 6 months to 2 years.³

What should I do if I suspect frozen shoulder?

Firstly, it is important that you discuss these concerns with your GP as frozen shoulder can have multiple pre-disposing risk factors. They may also advise that you get support from a physiotherapist who will assess this physically and may then triage you, as appropriate.

However, there are many things you can do to help yourself if you have a frozen shoulder.

Try these tips, along with advice and treatment from you GP or physiotherapist:

If you need pain relief, take over-the-counter painkillers, such as paracetamol or ibuprofen (always speak to your GP first).⁴
Try heat or cold packs. These may help to reduce stiffness and swelling and help relieve pain.
Support your arm with pillows while sleeping or while sitting in a chair. In bed, this can prevent you rolling onto the affected side.
Try to keep using your arm as much as you can. It helps to keep your shoulder moving. You may need to stop certain activities that worsen the pain but aim for a balance between rest and activity (speak to a physiotherapist for assessment and guidance).

Instability disorders

Shoulder instability is the loss of comfort or function in the shoulder due to undesirable movement of the ball on the shoulder socket.

If the integrity of the structures around the shoulder joint is lost, then the shoulder will become unstable. This can lead to:

weakness,
pain,
dislocation (the ball coming out of the socket),
subluxation (the ball partially coming out of the socket),
and even compensatory stiffness.

A thorough assessment from a doctor and/or physiotherapist will help to determine the causes for this instability and how much of the instability is from trauma or structure.

How is it assessed and why does it happen?

To accurately assess the shoulder, it’s first determined how your instability has occurred. Shoulder instability is categorised on a spectrum with three main causes

Traumatic and structural – often requires immediate medical examination. For example, if you had an acute dislocation, you should immediately go to A&E for assessment and relocation. If surgery isn’t required, then a referral to physiotherapy is recommended. They will test movement, strength and stability of the shoulder and manage the return to normal function.
Atraumatic and structural – often caused by gradual changes to structures or congenital abnormalities in these structures of the shoulder. This can cause some areas to be tight and some areas to be weak and loose, leading to instability. Gradual changes in the structure of the shoulder may occur from repetitive activities in work or sport.
Muscle patterning and non-structural – this type of instability doesn’t involve any structural damage but is a result of a change in the way the muscles coordinate with each other to produce movement. This can cause a sense of instability or dislocation. People with these conditions can often voluntarily pop their shoulder in and out. Physiotherapists aim to return normal patterning through specific exercises, tools or manual therapies.

Acromioclavicular joint disorders

The Acromioclavicular joint (AC joint) is a key connection point of the shoulder and is located at the top of the shoulder between the shoulder blade and the collarbone, and facilitates shoulder movement and stability.

What are AC joint disorders?

AC joint injuries are very common. It is estimated that around 40% of shoulder injuries affect the AC joint.⁵

Some examples of AC joint disorders include:

Sprains/separations
Dislocations
Collarbone fractures
AC joint osteoarthritis⁵

The most common cause of AC joint pain is sprains or separations.

These types of injuries are caused by direct trauma to the shoulder (e.g. through a fall onto the shoulder). These result in injury to the surrounding soft tissue structure that can cause the joint to become unstable and painful, which can affect the shoulder function.

The AC joint is also a common place that symptomatic arthritis may develop. This is a degenerative condition that leads to the reduction in AC joint cartilage, causing pain and swelling.

This type of arthritis is prevalent among weightlifters and manual labourers i.e. individuals who engage in repetitive overhead activities and movements.⁶

How are they assessed?

When experiencing shoulder pain, it can be hard to say for certain it’s in your AC joint. Pain can be located directly over the AC joint or can spread to your neck, lower shoulder or to the muscles in your chest or back.

Common symptoms of AC joint injuries include:

Pain over the AC joint.
Noticeable bump or deformity (in cases of separation).
Swelling and tenderness around the joint.
Shoulder tightness and reduced movement.
Pain when lifting the arm up to the side or across the front of the body.

If you take a direct impact to the shoulder and experience pain, especially associated with a pop or crack sound, it is always recommended to go to your GP. In more severe cases:

where you are unable to move the shoulder,
have sudden numbness,
extreme pain,
or deformity from the impact

it is safest to go to A&E.

Less severe conditions will be assessed and treated with physiotherapy.

Next steps

Shoulder pain is a common condition, and symptoms can be a result of varying factors such as age-related changes, injury, or repetitive movements. However, most conditions will improve with time and simple changes to lifestyle, alongside appropriate treatment and exercise.

It’s worth noting, that if your shoulder pain doesn’t improve or worsens overtime then it is always recommended to speak to your GP or a physiotherapist who can assess you further.

>For more on any muscle, bones or joint concerns then visit our musculoskeletal hub.