Frozen shoulder, or adhesive capsulitis, is a condition that causes pain and limited range of motion in the shoulder affecting 2-5% of the global population, as noted in a 2024 review of adhesive capsulitis in the National Library of medicine.

Early intervention especially through physical therapy, as highlighted by John Hopkins medicine, has proven beneficial in the management of various symptoms of frozen shoulders.

This article aims to provide evidence-based physiotherapy strategies, including specific exercises, to alleviate symptoms and enhance mobility in individuals suffering from frozen shoulders.

What is Frozen Shoulder: Definition

An article on WebMD notes frozen shoulder (adhesive capsulitis) as a condition that causes pain, stiffness, and limited movement in the shoulder joint. It typically develops gradually, worsens over time, and eventually resolves.

Frozen shoulder is often associated with various underlying health conditions, including diabetes and Dupuytren’s contracture. Furthermore, the sedentary lifestyle prevalent in modern society, marked by prolonged inactivity and immobility, plays a significant role in the development of shoulder joint stiffness.

One clinical difference between frozen shoulder and other shoulder related conditions (e.g osteoarthritis, rotator cuff tear etc) is that it causes stiffness to the shoulder joints.

Frozen shoulders can occur in individuals across various demographics, regardless of health status. Additionally, injuries, surgeries, or sudden trauma may precipitate the onset of frozen shoulder.

Symptoms of Frozen Shoulder

Frozen shoulder symptoms typically improve over time, with full recovery possible within 3 years. When risk factors are present, frozen shoulder symptoms can spontaneously present as:

Sudden, unexplained shoulder pain
Difficulty lifting your arm overhead or across your body as a result of shoulder joint stiffness and pain.
Pain or stiffness in one shoulder (rarely both).

Recognizing the stages of frozen shoulder can give more depth to how these symptoms listed progress and guide the choice of exercises and help patients track their progress.

Stages of Frozen Shoulder

Illustration of frozen shoulder showing the three stages of stiffness and limited movement in the glenohumeral joint. Image from csog.net

Stage 1: Freezing (2-9 months)

Shoulder movements trigger pain
Limited mobility and stiffness set in
Painful and frustrating, but gradual progression

Stage 2: Frozen (4-12 months)

May subside, but stiffness worsens
Using the shoulder becomes increasingly difficult
Limited mobility and rigidity peak

Stage 3: Thawing (5-24 months)

Shoulder mobility starts to improve
Range of motion increases
Gradual recovery and return to normal function

Now that common symptoms and stages that affect frozen shoulder patients have been highlighted, it’s important to understand the anatomy of shoulder joints.

Brief Anatomy of Shoulder Joint

Understanding the shoulder joint anatomy is crucial, as the glenohumeral joint’s (shoulder joint) unique structure predisposes it to stiffness and pain.

The shoulder joints consist of three bones: The acromion, clavicle and scapular. These three bones are joined together by two joints, the acromioclavicular and glenohumeral joints (the head of the humerus making contact with the glenoid cavity of the scapula). Frozen shoulder affects the bones and ligaments that make up the glenohumeral joint.

John Hopkins Medicine further explains that the shoulder is enclosed in a capsule of connective tissues called the glenohumeral joint capsule. This capsule normally expands and contracts according to movements around the shoulder.

Frozen shoulder occurs as a result of inflammation of the capsule or the surrounding connective tissues which could cause scarring. These scars cause adhesions. Thus the name of the condition being: adhesive (scarring), capsulitis (inflammation of the capsule).

Depending on how Frozen shoulder occur, it can be of two different types:

Types of Frozen Shoulder: Primary and Secondary

A research on physical therapy in management of frozen shoulder published in the National Library of Medicine asserts that:

Primary (Idiopathic) Frozen Shoulder

Primary frozen shoulder often occurs without a known cause. It is defined as being linked to:

Diabetes mellitus
Thyroid diseases
Parkinson’s disease

Secondary Frozen Shoulder

Secondary frozen shoulder is defined as being associated with:

Shoulder injuries (e.g., rotator cuff tears)
Immobilization (e.g., subacromial impingement)
Shoulder pathologies (e.g., biceps tenosynovitis, calcific tendonitis)

Understanding the factors that contribute to secondary frozen shoulders, such as shoulder injuries, immobilization, and other pathologies, helps to grasp the broader scope of this condition.

These underlying causes, along with the occurrence of primary frozen shoulder, play a significant role in the overall prevalence of the condition among different populations. To better understand the impact of frozen shoulder, let’s look at its prevalence across various demographics and how often it affects individuals worldwide.

Prevalence of Frozen Shoulder

Publications referenced by Physiopedia stated key statistics about the prevalence of frozen shoulder across the following demographics:

1.⁠ ⁠Gender:

- Approximately 70% of individuals with frozen shoulders are female.

- Cleveland Shoulder Institute notes menopause and hormonal imbalances as potential contributing factors.

2.⁠ ⁠Age:

- Typically affects individuals between 35-65 years old.

- Occurrence rate of 2-5% in this age group.

- Nicknamed "50-year-old shoulder" in China and Japan due to common prevalence among 50-year-olds.

3.⁠ ⁠Diabetic Population:

- 20% occurrence rate.

- According to a research on diabetes as a risk factor of frozen shoulder published on PubMed, it has been suggested that diabetes may be a cause of frozen shoulder through glycation processes and/or inflammatory processes leading to capsular fibrosis and subsequent contracture

4.⁠ ⁠Recurrence Risk:

- Contralateral shoulder involvement: 5-34%.

- Simultaneous bilateral involvement: 14% of cases.

Risk factors associated with Frozen Shoulders

Hospital of Special Surgery explains various frozen shoulders risk factors. This includes:

Thyroid diseases
Diabetes
Autoimmune disease or injury
Stroke
Depression and anxiety (Psycho Emotional factors)
Heart attack
Prolonged immobilization
Age (40–65 years)
Gender (women are affected more than men)
Previous episode of frozen shoulder on the contralateral side.

Also:

*Verywell online notes the increased risk of frozen shoulder symptoms with thyroid diseases might be related to an inflammatory process stimulated by the production of proteins known as cytokines (proteins that act as messengers between cells). Elevated levels of cytokines happen in both hyperthyroidism and frozen shoulder.

*Arm paralysis as a result of stroke causes frozen shoulders due to extended periods of immobility. The effects of gravity puts a strain on ligaments and capsule around the shoulder joints

Pathogenesis of Frozen Shoulder

The pathogenesis of frozen shoulders involves inflammation, scarring, and nerve damage. Essentially, the immune system reacts overly aggressively, leading to tissue damage and scarring.

This process involves various chemicals (cytokines) that promote inflammation and scarring. As a result, the connective tissue around the joint becomes imbalanced, leading to the deposition of scar tissue and joint contraction. This contraction causes pain and stiffness, creating a cycle that perpetuates the condition

For deeper insight into how frozen shoulders happen, check out this Research.

Physiotherapy Assessment of Frozen Shoulder

Subjective Assessment.

The following subjective assessment procedures were highlighted by Mezian and Chang (2023) in their publication on Frozen shoulder.

Presenting complaint

Assessment starts by noting the patient’s presenting complaint (PC). The presenting complaints in this case are usually common Frozen shoulder symptoms. Next, listen to the patient narrate the history of their presenting complaints (Hx PC).

Past medical history

Past medical history is assessed as this could rule out red flags and guide in accurate shoulder mobility examination.

Pain characteristics and distribution

Frozen shoulder patients typically experience a distinct pain profile, featuring:

⁠Severe night pain
Excrabation with sudden or uncontrolled movements
Discomfort when lying on the affected shoulder
Easy aggravation by movement
Radiating pain from the base of the skull, from down the arm into the hand.

Aggravating Factors and Functional Impairments

It’s important to know the activities of daily living that exacerbate these painful symptoms. It could be simple task such as:

Overhead reaching (e.g., hanging clothes)
Lateral movements (e.g., fastening seat belts)

Restricted shoulder rotation significantly impacts daily functioning, making personal hygiene, dressing, and grooming (e.g., brushing hair) challenging.

Objective Assessment

This should include performing the following:

Observation

On looking at the patient, they would present with scapular winging observed from the posterior and/or lateral view.

Examination

On examination Rundquist et al., 2003 reveals that frozen shoulder patients experience substantial restrictions in shoulder rotation. While external rotation is impaired in both neutral and 90-degree abduction, internal rotation is most severely affected, especially at 90 degrees of abduction.

Range of motion assessments

In frozen shoulders, range of motion restrictions follow a capsular pattern, indicating joint irritation. The shoulder's capsular pattern is characterized by external rotation (ER) limitations exceeding abduction (ABD), which in turn exceed internal rotation (IR) limitations (ER > ABD > IR). Notably, ER is significantly more restricted than ABD and IR, which show similar limitations.

Glenohumeral ligaments tests

The glenohumeral ligaments includes; Inferior glenohumeral ligament, Middle glenohumeral ligament, Superior glenohumeral ligament, Coracohumeral ligament. These ligaments are responsible for maintaining the stability and mobility of the shoulder.

Clinicians should perform specific tests to assess each GH ligament as they support the shoulder during different sections of movement along the joint.

Resisted muscle tests

Shoulder external rotation (ER)/ Internal rotation (IR)/abduction (ABd) (seated) should be performed. Patients with frozen shoulders present with weakness in shoulder ER, IR and ABd relative to the asymptomatic side.

Patients may also present with significant muscle guarding. Being aware of the stage of frozen shoulder you suspect your patient to be in, before subjecting them to muscle testing (manual muscle testing or with an isokinetic dynamometer) is important.

Special tests

Jia et al., 2008 highlights the shoulder shrug sign, characterized by the inability to lift the arm to 90° abduction without elevating the entire scapula or shoulder girdle, was initially associated with rotator cuff disease. However, it is more commonly linked to conditions such as glenohumeral arthritis, frozen shoulder, and massive rotator cuff tears.

Diagnosis of Frozen Shoulder

-There is no specific clinical test or gold standard for diagnosing frozen shoulder.

-Misdiagnosis is common due to similarities with other shoulder conditions.

-Assessing active and passive range of motion is crucial, as stiffness is a key characteristic.

-Yoon et al 2017 argued that imaging studies like MRI can help identify patho-anatomical features associated with frozen shoulder, including:

- Capsular thickening and enhancement

- Axillary recess thickening

- Rotator interval soft tissue thickening

-X-rays can help rule out osteopathies.

These points highlight the importance of a comprehensive evaluation, including clinical assessment and imaging studies, to accurately diagnose frozen shoulder.

Differential Diagnosis of Frozen Shoulders

Differential diagnosis is crucial in managing frozen shoulder because it helps clinicians rule out other conditions that may present similar symptoms, ensuring accurate treatment and optimal outcomes.

See diagram below for deeper understanding:

Physical Therapy Management of Frozen Shoulder.

Many physiotherapy exercises and strategies have proven effective in management of frozen shoulders symptoms. Physiotherapists begin treatment with patient education so the patient understands how the diagnosis was gotten and potential progression of their symptoms.

It also helps to level the ground- the patient would understand what they are in for and helps to reduce frustration. Symptoms may last up to 3 years and sometimes, full range of motion may never be fully achieved.

NSAIDS when used with physical therapy were more effective and recorded longer pain relief. It is imperative to consider the patient’s symptoms and stage of the condition when selecting a physical treatment method for frozen shoulder.

A research on physiotherapy management of frozen shoulder published by Chan et al, 2017 recommends the following procedures:

Freezing phase:

Pain tends to be most intense during the freezing phase, so patients at this stage can benefit from pain-relieving techniques.

Before starting exercises, applying a heat or ice pack can help alleviate discomfort. Using moist heat combined with stretching has been shown to enhance muscle flexibility. Some patients may also find it helpful to take pain relievers before beginning physical therapy.

Exercises used during Freezing phase includes:

Gentle shoulder mobility exercises

These should be done within a comfortable range are recommended, such as:

Pendulum exercises,
Passive supine forward elevation,
Passive external rotation, and
Active-assisted range of motion in extension, horizontal adduction, and internal rotation.

Pendulum exercises can be done by moving the arm forward, to the side, or in circles.

You can also try other exercises like using a pulley or relaxing the neck and shoulder blade muscles, as long as it feels comfortable.

It’s important not to push the shoulder too hard, as stretching too much beyond your pain limit can make things worse, especially in the early stages. Research also shows that keeping the shoulder in a neutral position helps, as slouching forward can limit how much you can lift or move your arm.

Photographs show examples of stretching exercises: (a) active assisted shoulder forward flexion with wand; (b) active assisted shoulder external rotation with wand; and (c & d) pendulum exercise.

Frozen Phase

During the frozen phase, just as in the freezing phase, applying a heat or ice pack before starting exercises can help alleviate pain. Home exercises, like those illustrated in the figure above, should be continued as long as they remain within a comfortable range.

The stretching exercises used in the freezing phase are still important, especially for the chest muscles and those at the back of the shoulder. Rotation exercises, like gently turning the arm outward before lifting it, can help reduce pain and swelling.

Strengthening exercises are added here to keep the muscles strong and prevent them from shrinking. Isometric or static exercises, which don’t require moving the joint, can be done without making the shoulder pain worse.

The figure below shows some strengthening exercises you can try at home. Scapular retraction exercises gently stretch the chest while building strength in the muscles around the shoulder blade.

Isometric shoulder exercises can also be done to strengthen the muscles involved in lifting the arm. However, it’s important not to push too hard with these exercises, as that could make shoulder inflammation worse and increase pain.

Photographs show examples of strengthening exercises: (a) scapular retraction; (b) posterior capsule stretch; and (c) isometric shoulder external rotation. In scapular retraction, the scapulae are pulled towards each other (arrows in a)

Thawing phase

During the thawing phase, patients slowly regain movement in their shoulders. The goal is to restore full movement and strength as soon as possible.

Because the shoulder is often weaker after months of limited use, strengthening exercises become very important. Unlike the frozen phase, patients can now do more mobility exercises and stretches (like those shown in Figures 2 and 3), holding each stretch longer as they can tolerate it.

Strengthening exercises should progress from holding positions without movement (isometric) to using resistance bands, and eventually to using free weights or weight machines.

Other exercises to include are those that target the rotator cuff, improve posture, and strengthen the deltoid and chest muscles.

Conclusion

Physiotherapy plays a vital role in the management of frozen shoulders, significantly improving range of motion, reducing pain, and accelerating recovery. Early intervention through gentle stretching and strengthening exercises tailored to each stage of the condition can minimize disability and prevent long-term complications.

If you're experiencing symptoms of a frozen shoulder, don't delay! Consult a physiotherapist to develop a personalized treatment plan and regain optimal shoulder function

Summary of key points

Patients with frozen shoulders typically experience insidious shoulder stiffness and near-complete loss of passive and active external rotation of the shoulder.

Frozen shoulder occurs in three phases: freezing (painful), frozen (adhesive) and thawing, and is often self-limiting.

Common conservative treatments for frozen shoulders include NSAIDs, glucocorticoids given orally or as intra-articular injections, and/or physical therapy.

Physical therapy and home exercises can be a first-line treatment for frozen shoulders, with consideration of the patient’s symptoms and stage of the condition.

In the freezing (painful) stage, gentle stretching exercises can be done but should be kept within a short duration (1–5 seconds) and not go beyond the patient’s pain threshold.

In the frozen (adhesive) stage, strengthening exercises such as scapular retraction, posterior capsule stretch and isometric shoulder external rotation can be added to the patient’s exercises for maintenance of muscle strength.

In the thawing stage, the patient experiences a gradual return of range of motion; both stretching and strengthening exercises can increase in intensity, with a longer holding duration.

Dupuytren’s contracture is a condition where one or more fingers become bent toward the palm and cannot fully straighten

Studies consistently show that early intervention leads to faster recovery, making physiotherapy a crucial part of treatment.

References:

Rundquist, P. J., Anderson, D. D., Guanche, C. A., & Ludewig, P. M. (2003). Shoulder kinematics in subjects with frozen shoulders. Archives of Physical Medicine and Rehabilitation, 84(11), 1473-1479.
Jia, X., Ji, J. H., Petersen, S. A., Keefer, J., & McFarland, E. G. (2008). Clinical evaluation of the shoulder shrug sign. Clinical Orthopaedics and Related Research, 466(11), 2813-2819. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2565053/

Global Population Health Series ::: Nov 2024

Introduction