Frozen shoulder (also known as adhesive capsulitis or periarthritis) is used to describe the condition where the glenohumeral joint of the shoulder is stiff and painful. It occurs in about 2-5% of the general population, with a higher prevalence among elderly individuals and those with diabetes. Frozen shoulder is a benign and self limiting condition, usually lasting for 1-3 years, in 20-50% of patients the stiffness and pain only partially resolve, which leads to long lasting effects of shoulder mobility impairment and reduction in sleep quality. Commonly patients who suffer persistent symptoms (over 4-5 years) only suffer mild long term effects.
Anatomy
The hallmark pain and stiffness are caused by the formation of adhesions or scar tissue in the glenohumeral (GH) joint. The GH joint is a ball and socket joint between the scapula and humerus, connecting the upper arm to the trunk. Under normal conditions this joint is one of the most mobile in the human body, allowing for a large range of motion in multiple planes. In the case of frozen shoulder the adhesions limit this range of motion and make movement painful.
Symptoms
There are 4 recognised clinical stages of the condition:
- Painful stage- moderate pain and reduction of movement lasting less than 3 months
- Freezing stage- severe pain and reduction of movement lasting 3-9 months
- Frozen stage- pain may be present but stiffness predominates lasting 10-14 months
- Thawing stage- minimal pain and gradual improvement in movement lasting 14-24 months
Causes
The cause of frozen shoulder is still unclear. Historically researchers into the aetiology of the condition have shown that it is characterised by a thickened, tight capsule with chronic inflammatory cells and fibroblasts found in the joint capsule. It can occur as a primary idiopathic condition or secondary to medical conditions or trauma.
Diagnosis
Frozen shoulder is diagnosed by testing positive to three characteristics:
- Insidious onset of severe pain over a period of months, night time pain is a common feature
- Shoulder stiffness with markedly reduced external rotation
- Negative radiographic findings
Some patients describe the pain as a deep ache, poorly localised and non specific without any point of tenderness. In others it presents as a pain which refers to the deltoid origin and radiates down to the bicep area. Manual testing will often return normal rotator cuff strength but a greatly reduced passive and active range of motion.
In some cases laboratory tests may be carried out to identify or rule out underlying conditions. Radiographs of the shoulder will also return normal with a patient suffering from frozen shoulder, but may be carried out to exclude conditions such as shoulder dislocation, GH arthritis or calcific tendinopathy.
Treatment
There is no universally accepted intervention which is viewed as the most effective treatment for restoring motion and reducing pain.
Non-surgical or conservative management is preferred with most patients improving in 6-18 months. This includes analgesics, oral steroids, physical therapies and supra-scapula nerve block. Physical therapy, from a sports massage and remedial therapist or physiotherapist, has traditionally been the first choice of treatment for frozen shoulder. The therapist can work to reduce pain, mobilise the joint and provide the patient with a supervised stretching and strength maintenance programme.
Exercises
Exercises should be carried out under the direction of a qualified therapist and vary according to the stage of the condition.
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Early Freezing Stage: Gentle and Short Duration Stretches
- Pendulum Exercises
- Purpose: Promote gentle movement in the shoulder joint, reducing stiffness without causing pain.
- How to Perform:
- Lean forward with your unaffected arm supported on a table or chair.
- Let your affected arm hang down loosely.
- Gently swing your arm in small circles, or forward and back, using your body to initiate the motion.
- Perform for 1-2 minutes, gradually increasing the range of motion as tolerated.
- Passive External Rotation
- Purpose: Maintain range of motion by gently stretching the external rotators of the shoulder.
- How to Perform:
- Lie on your back with your arm close to your side and elbow bent at 90 degrees.
- Use your unaffected hand to gently push your affected arm outward, rotating it externally.
- Hold for 10-15 seconds, then relax and repeat, avoiding any pain.
- Supine Passive Forward Elevation
- Purpose: Improve shoulder mobility by gently stretching the shoulder in a pain-free range.
- How to Perform:
- Lie on your back with your affected arm by your side.
- Use your unaffected hand to slowly lift your affected arm overhead, keeping it straight.
- Hold at the top for a few seconds, then slowly lower it back down.
- Repeat, ensuring the movement remains gentle and within a comfortable range.
Later Frozen Stage: Strengthening Exercises
- Isometric External Shoulder Rotation
- Purpose: Strengthen the shoulder’s external rotators, stabilising the joint without moving it.
- How to Perform:
- Stand with your elbow bent at 90 degrees, and press the back of your hand against a wall or door frame.
- Push outward against the wall without moving your arm, holding the tension for 10-15 seconds.
- Relax and repeat, ensuring no pain occurs during the exercise.
- Posterior Capsular Stretching
- Purpose: Stretch the tight posterior capsule of the shoulder, improving internal rotation and overall flexibility.
- How to Perform:
- Bring your affected arm across your body at shoulder height.
- Use your other hand to gently pull your arm closer to your chest, stretching the back of your shoulder.
- Hold the stretch for 20-30 seconds, then release and repeat.
Thawing Stage: Combined Strength and Stretching Exercises
- Combined Strength and Stretching Exercises
- Purpose: Enhance overall shoulder function by combining strengthening with stretching, gradually increasing range of motion and strength.
- How to Perform:
- Incorporate exercises like active external rotations, shoulder abduction, and flexion against light resistance bands or weights.
- Alternate between strengthening movements and stretching exercises like doorway stretches or wall slides.
- Increase the frequency and intensity as tolerated, aiming for 2-3 times daily.
- Pendulum Exercises
Prevention
As the aetiology of the condition is still unknown advising on how to prevent an incidence of the condition is difficult. Research has suggested that prolonged immobilisation or limited use of the shoulder joint may contribute to the likelihood of developing frozen shoulder. With this in mind regular balanced exercise and stretching can help to maintain the structural support and mobility of the GH joint.
