Frozen Shoulder; Causes, Symptoms, Diagnosis, Treatment

Frozen shoulder is an extremely painful and debilitating condition leading to stiffness and disability. It typically occurs in the fifth and sixth decades of life, thus affecting individuals of working age. The disability resulting from this condition has a considerable economic impact on affected individuals and society.

Frozen shoulder can be either primary (idiopathic) or secondary. Secondary frozen shoulder is defined as that associated with trauma; rotator cuff disease and impingement; cardiovascular disease; hemiparesis; or diabetes (although some classify this in diabetics as primary frozen shoulder). The incidence of frozen shoulder in people with diabetes is reported to be 10% to 36%, and these tend not to respond as well to treatment as in nondiabetics.¹

Adhesive capsulitis (also known as frozen shoulder) is a painful and disabling disorder of unclear cause in which the shoulder capsule, the connective tissue surrounding the glenohumeral joint of the shoulder, becomes inflamed and stiff, greatly restricting motion and causing chronic pain. Pain is usually constant, worse at night, and with cold weather. Certain movements or bumps can provoke episodes of tremendous pain and cramping. The condition is thought to be caused by injury or trauma to the area and may have an autoimmune component.

Frozen shoulder, also known as adhesive capsulitis, is a common condition in which the articular shoulder capsule (a sac of ligaments surrounding the joint) swells and stiffens, restricting its mobility. It typically affects only one shoulder, but one in five cases affect both.

Stage of Frozen Shoulder

The normal course of a frozen shoulder has been described as having three stages

Three phases of clinical presentation

Painful freezing phase

Duration 10-36 weeks. Pain and stiffness around the shoulder with no history of injury. A nagging constant pain is worse at night, with little response to non-steroidal anti-inflammatory drugs

Adhesive phase

Occurs at 4-12 months. The pain gradually subsides but stiffness remains. Pain is apparent only at the extremes of movement. Gross reduction of glenohumeral movements, with near total obliteration of external rotation

Resolution phase

Takes 12-42 months. Follows the adhesive phase with spontaneous improvement in the range of movement. Mean duration from onset of frozen shoulder to the greatest resolution is over 30 months

Anatomy of Frozen Shoulder

The term “frozen shoulder” is often used incorrectly for arthritis, even though the two conditions are unrelated. Frozen shoulder refers specifically to the shoulder joint, while arthritis may refer to other/multiple joints.

The shoulder has a spheroidal joint (ball – and – socket joint), in which the round part of one bone fits into the concavity of another. The proximal humerus (round head of the upper arm bone) fits into the socket of the scapula (shoulder blade). Frozen shoulder is thought to cause the formation of scar tissue in the shoulder, which makes the shoulder joint’s capsule (not to be confused with the rotator cuff) thicken and tighten, leaving less room for movement.

The humerus is the upper arm bone. This is the “ball” of the shoulder’s “ball and socket” joint. The scapula is the flat, triangular bone commonly called the shoulder blade. Prominent areas of the scapula serve as attachment points for many muscles and ligaments.

• The glenoid is the shallow “socket” on the side of the scapula that receives the ‘ball’ of the humerus. Together they form the “ball and socket” arrangement of the shoulder.
• The scapular spine is a horizontal ridge along the back of the scapula that divides the scapula into upper and lower regions.
• The acromion is the end of the scapular spine. It projects up to form the top of the shoulder.
• The coracoid process is a projection towards the front of the scapula and is an attachment site for several muscles and ligaments.
• The clavicle is the collarbone. Although it appears to be straight, it actually forms an S-shape when seen from above.
• The thorax or rib cage is an anchor for several muscles and ligaments. Although the ribs do not physically attach to the scapula, the thorax stabilizes and maintains proper positioning of the scapula so that the arm can function to its fullest capacity.

The modern English words “adhesive capsulitis” are derived from the Latin words adhaerens meaning “sticking to” and capsule meaning “little container” and the Greek word itis meaning “inflammation”.

Additionally, there are four bone junctions or joints:

• The glenohumeral joint is the main joint of the shoulder. Here, the glenoid on the scapula and the head of the humerus come together. The fairly flat socket of the glenoid surrounds only 20% – 30% of the humeral head. Because of its poor fit, this joint relies heavily on the surrounding soft tissue for support. The labrum, a ring of fibrocartilage tissue, attaches to the glenoid and deepens the socket to encircle more of the humerus.
• The acromioclavicular joint, or AC joint, is the bony point on the top of the shoulder. It stabilizes the scapula to the chest, by connecting the acromion on the scapula to the clavicle, or “collarbone”. A thick disk of fibrocartilage acts as a shock absorber between the two bones. The surrounding capsule and ligaments give this joint great stability.
• The sternoclavicular joint, or SC joint, connects the other end of the clavicle to the sternum, or “breastbone”. Like the AC joint, this joint contains a fibrocartilage disk that helps the bones achieve a better fit. It also gets excellent support from its joint capsule and surrounding ligaments.
• The scapulothoracic articulation is the area where the scapula, embedded in muscle, glides over the thoracic rib cage. The surrounding muscles and ligaments keep the scapula properly positioned so that the arm can move correctly.

Cartilage

There are two types of cartilage in the shoulder

Articular cartilage is the shiny white coating that covers the end of the humeral head and lines the inside surface of the glenoid. It has two purposes:

• To provide a smooth, slick surface for easy movement
• To be a shock absorber and protect the underlying bone

Fibrocartilage – is the thick tissue that forms the disks of the AC and SC joints and the labrum, the ring that deepens the glenoid. Fibrocartilage has three roles:

• To act as a cushion in shock absorption
• To help stabilize the joint by improving the fit of the bones
• To act as a spacer and improve contact between the articular cartilage surfaces

Ligaments

The shoulder relies heavily on ligaments for support. Ligaments attach bone to bone and provide the “static” stability in a joint. Ligaments will alternately become tight and loose with normal motion. They keep the joint within the normal limits of movement.

• The glenohumeral ligaments attach in layers from the glenoid labrum to form the joint capsule around the head of the humerus.
• The coracoacromial arch is the group of ligaments that spans the bony projections of the coracoid process and the acromion.
• The coracoclavicular ligaments and the acromioclavicular ligament provide most of the support for the AC joint.

Muscles and Tendons

Muscles and tendons work together in the shoulder to provide the “dynamic” stability of the shoulder.

There are four muscle groups in the shoulder:

• The rotator cuff muscles are the subscapularis, the supraspinatus, the infraspinatus, and the teres minor. They are the primary stabilizers that hold the “ball” of the humerus to the glenoid “socket”. The socket is too shallow to offer much security for the humerus. These four muscles form a “cuff” around the humeral head, securing it firmly in the socket. As its name implies, this group of muscles also rotates the arm. The rotator cuff protects the glenohumeral joint from dislocation, allowing the large muscles that control the shoulder to power the arm with great mobility.
• The biceps tendon complex also helps keep the humeral head in the glenoid and helps raise the arm.
• The scapulothoracic muscles attach the scapula to the thorax. Their main function is to stabilize the scapula to allow for proper shoulder motion.
• The superficial muscles of the shoulder are the large, powerful outer layer of muscles that are important to the overall function of the shoulder. This group includes the deltoid muscle, which covers the rotator cuff muscles.

Causes of Frozen Shoulder

Age & Gender – Frozen shoulder most commonly affects patients between the ages of 40 to 60 years old. It is twice more common in women than in men.

Endocrine (Hormonal) Disorders – Patients with diabetes are at particular risk for developing frozen shoulder. People with other endocrine abnormalities, such as thyroid problems, may also be predisposed to developing frozen shoulder.

Shoulder Trauma or Surgery – Patients who sustain a shoulder injury, or undergo shoulder surgery or vaccinations in the shoulder muscle can develop frozen shoulder. When injury or surgery is followed by prolonged joint immobilization such as putting the shoulder in a sling, the risk of developing frozen shoulder is highest.

Other Systemic Conditions – Several systemic conditions such as heart disease and Parkinson’s disease have also been associated with an increased risk of developing frozen shoulder.

Psychosomatic overlay – It is also hypothesized that some patients also develop frozen shoulder due to severe stress causing a psychosomatic reaction, especially if they feel emotionally restricted and pressured or “frozen” in the decision-making process.

The cause of frozen shoulder is not fully understood and in some cases is unidentifiable. However, most people with frozen shoulder have suffered from immobility as a result of a recent injury or fracture. The condition is common in people with diabetes.

Common risk factors for frozen shoulder are

You’re more likely to suffer from frozen shoulder if you’re female and over 40 years of age.

• Age – being over 40 years of age.
• Gender – 70% of people with frozen shoulder are women.
• Recent surgery or arm fracture – immobility of recovery may cause the shoulder capsule to stiffen.
• Diabetes – two to four times more likely to develop frozen shoulder for unknown reasons; symptoms may be more severe.
• Having suffered a stroke.
• Hyperthyroidism (overactive thyroid).
• Hypothyroidism (underactive thyroid).
• Cardiovascular disease (heart disease).
• Parkinson’s disease.

Symptoms of Frozen Shoulder

Early symptoms of frozen shoulder

• A feeling of pain and tightness in the shoulder area.
• A feeling of tightness especially when putting the arm up and back, as you would do if you were throwing a ball overarm.
• Pain on the back of the wrist. (This specifically relates to frozen shoulder caused by subscapularis trigger points.)
• Dull, aching Pain
• Sleep disturbance and deprivation
• Severe sharp pain with rapid movement (eg. trying to catch mobile phone)
• The difficulty with activities of daily living (eg. dressing, driving and personal care)
• Lack of movement in all directions
• As time goes on, the symptoms will worsen although the pain may be reduced.

The typical symptoms are a pain, stiffness, and limitation in the range of movement of one of your shoulders. The symptoms typically have three phases

• Phase one – the ‘freezing’, painful phase. This typically lasts 2-9 months. The first symptom is usually a pain. Stiffness and limitation in movement then also gradually build up. The pain is typically worse at night and when you lie on your affected side.
• Phase two – the ‘frozen’, stiff (or adhesive) phase. This typically lasts 4-12 months. The pain gradually eases but stiffness and limitation in movement remain and can become worse. All movements of your shoulder are affected. However, the movement most severely affected is usually a rotation of the arm outwards. The muscles around the shoulder may waste a bit as they are not used.
• Phase three – the ‘thawing’, recovery phase. This typically lasts between one and three years. The pain and stiffness gradually go and movement gradually returns to normal, or near normal.

Symptoms often interfere with everyday tasks such as driving, dressing, or sleeping. Even scratching your back, or putting your hand in a rear pocket, may become impossible. Work may be affected in some cases.

Diagnosis of Frozen Shoulder

The following outcome measures have been used in studies researching adhesive capsulitis.

• Shoulder Pain and Disability Index (SPADI)
• Disability of the Arm, Shoulder and Hand scale (DASH)
• American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES)
• Simple Shoulder Test (SST)
• Penn Shoulder Scale (PSS)
• NPRS
• VAS
• SF-36

Hand to neck

Shoulder flexion + abduction + ER

• Similar to ADLs such as combing hair, putting on a necklace

Hand to scapula

• Shoulder extension + adduction + IR
• Similar to ADLs such fitting a bra, putting on a jacket, getting into the back pocket

Hand to opposite scapula

• Shoulder flexion + horizontal adduction

These tests require appropriate elbow, scapulothoracic, and thoracic mobility and these areas should be cleared of pathology first. If a patient is unable to complete the motion, other structures outside of the shoulder joint may be the limiting factor.

Imaging

• X-ray – X-rays can help to ensure the shoulder joint appears normal, with no evidence of traumatic injury or arthritic changes.
• MRI – This powerful diagnostic tool can sometimes show inflammation, but this test is better at ruling out other problems, rather than looking for a frozen shoulder. If an MRI is conducted, an injection of contrast fluid into the shoulder joint prior to the MRI is necessary. Results indicating a scarred capsule would designate frozen shoulder.
• Ultrasound – can show the state of the rotator cuff tendons. Intact tendons in the setting of severe restriction in movement suggest frozen shoulder.
• Arthrogram – may be used with an MRI to provide further information about structures in the shoulder. A dye is injected into the shoulder and images are obtained. The dye creates a contrast on the image, making the specific location of adhesions and the reduced space typical of frozen shoulder more visible.

Treatment of Frozen Shoulder

The aim of treatment for frozen shoulder is to alleviate pain and preserve mobility and flexibility in the shoulder. However, recovery may be slow, as symptoms tend to persist for several years.

• Corticosteroid injection – Based on best available evidence, corticosteroid injection has mainly short-term benefit with a single injection. There appears to be added benefit with providing physiotherapy promptly following steroid injection compared to home exercise alone and physiotherapy alone. There is insufficient evidence to conclude with reasonable certainty in what clinical situations steroid injection, with or without physiotherapy, is most likely to be effective for treatment of frozen shoulder.
• Sodium hyaluronate injection – A small number of diverse studies, all of which may have a high risk of bias, provide insufficient evidence to make conclusions about the effectiveness of sodium hyaluronate in the treatment of frozen shoulder
• Physiotherapy/physical therapy – Primary studies comparing different types of physiotherapy/physical therapies support the use of various techniques to provide short- to medium-term benefit. Some interventions in current use that were investigated include therapeutic ultrasound end-range mobilization,²⁸ short-wave diathermies plus stretching²⁹ and high-grade mobilization therapy.³⁰These interventions should be stage of disease and response-dependent. Based on best available evidence, there may be benefit from short-wave diathermy plus stretching and high-grade mobilization techniques in patients who have already had physiotherapy or a steroid injection. There is insufficient evidence to make conclusions on the best mode of physiotherapy for frozen shoulder
• Acupuncture – The role of acupuncture in the treatment of frozen shoulder is not clear. Available evidence does not demonstrate a clear benefit.

• Treatment options for frozen shoulder include Painkillers – relieve symptoms of pain. Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, are over – the – counter (OTC, no prescription required) painkillers and may reduce inflammation of the shoulder in addition to alleviating mild pain. Acetaminophen (paracetamol, Tylenol) is recommended for extended use. Prescription painkillers, such as codeine (an opiate-based painkiller) may also reduce pain. Not all painkillers are suitable for every patient; be sure to review options with your doctor.
• Exercise – frequent, gentle exercise can prevent and even reverse stiffness in the shoulder.

Alternating between hot and cold compression packs can help with frozen shoulder

• Hot or cold compression packs – help to reduce pain and swelling. It is often helpful to alternate between the two.
• Transcutaneous electrical nerve stimulation (TENS) – numbs the nerve endings in the spinal cord that control pain and sends small pulses of electricity from the TENS machine to electrodes (small electric pads) that are applied to the skin on the affected shoulder.
• Physical therapy (UK: physiotherapy) – can teach you exercises to maintain as much mobility and flexibility as possible without straining the shoulder or causing too much pain.

Physiotherapy for Frozen Shoulder

Your physical therapist’s overall goal is to restore your movement, so you can perform your daily activities. Once the evaluation process has identified the stage of your condition, your physical therapist will create an individualized exercise program tailored to your specific needs. Exercise has been found to be most effective for those who are in stage 2 or higher. Your treatment may include:

Stages 1 and 2

• Exercises and manual therapy – Your physical therapist will help you maintain as much range of motion as possible and will help reduce your pain. Your therapist may use a combination of range-of-motion exercises and manual therapy (hands-on) techniques to maintain shoulder movement.
• Modalities – Your physical therapist may use heat and ice treatments (modalities) to help relax the muscles prior to other forms of treatment.
• Home-exercise program – Your physical therapist will give you a gentle home-exercise program designed to help reduce your loss of motion. Your therapist will warn you that being overly aggressive with stretching in this stage may make your shoulder pain worse. Your physical therapist will match your treatment activities and intensity to your symptoms, and educate you on the appropriate use of the affected arm. Your therapist will carefully monitor your progress to ensure a safe healing procedure is followed.
• Pain medication –  Sometimes, conservative care cannot reduce the pain of adhesive capsulitis. In that case, your physical therapist may refer you for an injection of a safe anti-inflammatory and pain-relieving medication. Research has shown that although these injections don’t provide longer-term benefits for a range of motion and don’t shorten the duration of the condition, they do offer short-term pain reduction.

Stage 3

The focus of treatment during phase 3 is on the return of motion. Treatment may include:

• Stretching techniques – Your physical therapist may introduce more intense stretching techniques to encourage greater movement and flexibility.
• Manual therapy – Your physical therapist may take your manual therapy to a higher level, encouraging the muscles and tissues to loosen up.
• Strengthening exercises – You may begin strengthening exercises targeting the shoulder area as well as your core muscles. Your home-exercise program will change to include these exercises.

Stage 4

In the final stage, your physical therapist will focus on the return of “normal” shoulder body mechanics and your return to normal, every day, pain-free activities. Your treatment may include:

• Stretching techniques – The stretching techniques in this stage will be similar to previous ones you’ve learned but will focus on the specific directions and positions that are limited for you.
• Manual therapy – Your physical therapist may perform manual therapy techniques in very specific positions and ranges that are problematic for you. They will focus on eliminating the last of your limitations.
• Strength training – Your physical therapist will prescribe specific strengthening exercises related to any weakness that you may have to help you perform your work or recreational tasks.
• Return to work or sport – Your physical therapist will address movements and tasks that are required in your daily and recreational life.

Rehabilitation program

The exercises and other treatment methods are dependent on which phase of rehabilitation the patient is at. We recommend seeking professional advice before attempting any rehabilitation.

Phase 1 – Freezing

• This phase is usually the most painful phase of treatment and movement becomes gradually more and more difficult. The aim of the following treatments and exercises is to help control pain and maintain movement in the shoulder joint.
  
• NSAID’s (nonsteroidal anti-inflammatory drugs) e.g. Ibuprofen may help reduce inflammation and pain although will be of less value in later phases of treatment. Check with a doctor before taking medication and do not take ibuprofen if you have asthma.
• Electrotherapy modalities such as ultrasound, TENS and laser treatment may all help reduce pain and inflammation.
• Exercises should be done as long as they can be performed pain-free. Mobility exercises such as the pendulum and assisted shoulder exercises using a pole can help maintain shoulder mobility. See adhesive capsulitis exercises for more detailed information.
• Shoulder stretching exercises for the muscles at the front and back of the shoulder can be done also to attempt to maintain as much movement as possible. Strengthening exercises are unlikely to be possible at this stage due to pain.

Phase 2 – Frozen

• During the frozen phase of treatment is where there is the least movement in the shoulder, but on the plus side, pain tends to have reduced. This phase should be about trying to maintain strength and as much mobility as possible.
• Mobility exercises such as pendulums and wand exercises should be continued. Stretching exercises for the chest muscles and muscles at the back of the shoulder should also be maintained.
• Strengthening exercises can be performed to maintain muscle strength. Isometric or static contractions are exercises needing no joint movement and can be done without worrying about movement in the shoulder. Try to maintain good posture by working the upper back muscles. Poor posture could be a contributing factor in frozen shoulder helping to cause it or prevent healing.
• A therapist may be able to help by performing some more advanced mobilizations on the shoulder to increase the range of movement at the shoulder joint. This is especially beneficial to patients who have very limited movement in the shoulder.

Phase 3 – Thawing

• The final phase of treatment and rehab is where movement starts to return to the shoulder. This phase is all about getting the shoulder back to normal as quickly as possible by regaining full movement and strength. After a few months with little movement, the shoulder will be considerably weakened so strengthening exercises are important.
• Mobility exercises and stretches can become more aggressive, but should still be within the boundaries of pain. Aim to restore full mobility in the shoulder joint.
• Strengthening exercises can progress from isometric or static contractions to exercises using a resistance band, then eventually free weights or weight machines.
• Work the affected shoulder first, do as many reps as you can and then do the same number on the unaffected shoulder. This will help avoid a muscle imbalance.

Include rotator cuff exercises in treatment as well as posture exercises and exercises for the deltoid and chest muscles too. The shoulder joint is a complicated joint and correct biomechanical function between the shoulder joint and shoulder blade is important as other shoulder injuries may follow if the joint is not fully rehabilitated.

Surgery

Margery for frozen shoulder is typically offered during “Stage 2: Frozen.” The goal of surgery is to stretch and release the stiffened joint capsule. The most common methods include manipulation under anesthesia and shoulder arthroscopy.

Manipulation under anesthesia – During this procedure, you are put to sleep. Your doctor will force your shoulder to move which causes the capsule and scar tissue to stretch or tear. This releases the tightening and increases the range of motion.

Shoulder arthroscopy – In this procedure, your doctor will cut through tight portions of the joint capsule. This is done using pencil-sized instruments inserted through small incisions around your shoulder.

Home Exercises 

Stiff or frozen shoulders are usually uncomfortable, even if the degree of stiffness is not great. That’s the bad news. The good news is that most stiff shoulders can be managed successfully by a simple exercise program conducted by the patient in the home.

Getting the shoulder moving

It is basically a question of gently and progressively getting the shoulder moving again. This program is the safest of all treatments for frozen shoulders. Although months of these specific exercises may be required, persistence almost always pays off. Even if arthritis is present, this program may help preserve and even improve the shoulder’s range and comfort. Before beginning these exercises you should consult with your physician.

There are two components to the home program for stiff shoulders. The first is a series of stretching exercises and the second relates to regular participation in a fitness program.

Your opposite arm is a great therapist for your stiff shoulder. Your “therapist arm” is always available to apply a gentle stretch in any direction of tightness. Each of these gentle stretches needs to be held up to a count of 100.

Stretching Exercises for the Frozen or Stiff Shoulder

The basic program includes the exercises illustrated below.  Click any image below to enlarge and view in our photo gallery.

References

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• https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4935124/
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• https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4935124/
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• https://orthoinfo.aaos.org/en/diseases–conditions/frozen-shoulder/
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