Frozen Shoulder: Why It Happens, Who Gets It and How We Treat It

You cannot reach behind your back to tuck in your shirt. Fastening a bra is impossible. Reaching for your seatbelt sends a sharp pain through your shoulder. At night, rolling onto that side wakes you up. The shoulder does not just hurt. It has stopped moving.

If this sounds familiar, you are likely dealing with frozen shoulder. It is one of the most frustrating conditions we see in the practice: painful, slow to improve and often poorly explained. But the research on what drives it and how to treat it has advanced significantly in recent years. Understanding the condition properly changes how you manage it.

What is frozen shoulder?

Frozen shoulder, known clinically as adhesive capsulitis, is a condition where the capsule surrounding the shoulder joint becomes inflamed and then progressively stiffens. The capsule is a sleeve of connective tissue that wraps around the entire glenohumeral (ball-and-socket) joint. When it thickens and contracts, the shoulder loses range of motion in all directions.

The hallmark of frozen shoulder is a global loss of movement, meaning it affects reaching forward, to the side, behind your back and into rotation. This distinguishes it from rotator cuff injuries, where movement is painful but often still possible with effort. With a true frozen shoulder, the movement is mechanically blocked. The joint simply will not go that far.

How frozen shoulder progresses

The condition moves through three overlapping phases: a painful (freezing) phase where pain dominates and movement starts to reduce, a stiff (frozen) phase where pain may ease but the shoulder locks up, making everyday tasks like dressing, driving and sleeping difficult, and a recovery (thawing) phase where the shoulder gradually loosens and movement returns.

Left to run its course, frozen shoulder is slow. Many sources still cite classic timelines of 1 to 3 years total duration, but those figures come from a 1975 natural history study of patients who received little or no treatment. Treated early and actively, the picture is very different. Kanokvaleewong and colleagues (2025) found that with conservative treatment, night pain resolved in approximately one month and meaningful range of motion improvement occurred within a year, regardless of initial severity. In our practice, where we combine mobilisation, shockwave therapy and targeted rehabilitation from the outset, we routinely see patients recover faster than even those study timelines.

The longer you wait, the longer it takes. Early treatment compresses the timeline.

Does it really go away on its own?

This is one of the most common things patients are told: just give it time, it will sort itself out. The evidence is more complicated than that.

Long-term follow-up studies show that only around 60% of patients achieve normal or near-normal shoulder function without treatment. Up to 50% retain some degree of movement limitation, and a small but meaningful number are left with persistent pain and functional loss years later.

Frozen shoulder usually improves substantially, but telling someone it will resolve completely on its own is not well supported by the evidence. Waiting it out is not a neutral decision. It means months of unnecessary pain, stiffness and lost function that active treatment can significantly reduce.

Who gets frozen shoulder?

Frozen shoulder was historically considered a random event. The emerging research suggests it is anything but.

Age. Peak onset is between 40 and 60. It is rare before 40 and uncommon after 70.

Sex. Women are affected roughly 1.5 times more often than men. This is likely related to hormonal factors.

Hormonal changes. This is where the research has moved significantly. A 2025 review by Navarro-Ledesma in the Journal of Clinical Medicine reframed frozen shoulder as a systemic condition driven by hormonal and metabolic factors rather than a localised joint problem. Oestrogen normally keeps inflammation in check and prevents the shoulder capsule from stiffening. When oestrogen levels drop during perimenopause and menopause, those protective effects weaken. On top of that, the type of oestrogen your body produces shifts after menopause, from a form that dampens inflammation to one that promotes it.

This is why frozen shoulder is so common in women in their late 40s and 50s. It is not coincidence. It is hormonal.

Thyroid disorders. An underactive thyroid has been found in 10% to 34% of frozen shoulder patients across studies, and genetic research supports a causal link rather than just an association. Thyroid dysfunction slows the body’s ability to remodel connective tissue and promotes the kind of fibrosis that stiffens the shoulder capsule. It also lowers the amount of active oestrogen available in the body, compounding the hormonal effect.

Diabetes. The strongest and most consistent risk factor. A 2023 systematic review by Dyer and colleagues found people with diabetes had nearly four times the odds of developing frozen shoulder. Chronically elevated blood sugar damages collagen and promotes the kind of tissue stiffening that drives the condition.

Other factors. Prolonged immobilisation after injury or surgery, Dupuytren’s contracture and cardiovascular disease are also associated with higher risk.

How we treat frozen shoulder

There is no single treatment that works for every stage of frozen shoulder. The best outcomes come from a multimodal approach tailored to where you are in the process. A 2025 narrative review by Kim and colleagues in Clinical Shoulder and Elbow advocates exactly this: individualised, multimodal care that progresses based on symptoms and response.

Chiropractic adjustments and mobilisation

The shoulder does not work in isolation. Stiffness in the thoracic spine, restricted neck movement and altered scapular mechanics all change how load passes through the shoulder joint. Mobilisation of the shoulder, thoracic spine and cervical spine reduces compensatory strain and helps restore movement.

Mobilisation is most effective when delivered as part of a combined programme rather than as a standalone treatment.

Shockwave therapy

Shockwave therapy is one of the most promising non-invasive treatments for frozen shoulder, and the evidence base is growing.

A systematic review and meta-analysis by Zhang and colleagues (2022) pooled data from 20 randomised controlled trials and found that shockwave significantly reduced pain and improved shoulder function. External rotation improved by an average of 10.3 degrees. The authors concluded that shockwave is beneficial as adjunctive therapy for pain relief and functional improvement in frozen shoulder.

What makes the evidence particularly compelling is a 2024 double-blinded, placebo-controlled trial by Nambi and colleagues. Sixty patients received either shockwave plus lidocaine injection or a sham treatment. At six months, the shockwave group showed 23.6 degrees greater abduction, 18.1 degrees greater lateral rotation and a 16.2-point improvement in functional score compared to placebo. MRI confirmed measurable structural changes: a 0.6mm reduction in coracohumeral ligament thickness. This is important because it demonstrates shockwave produces real tissue-level change, not just symptom relief.

At our practice we use the EMS Swiss DolorClast Smart20 and typically deliver sessions weekly, combined with manual therapy and rehabilitation in the same visit.

Dry needling

Dry needling targets the myofascial trigger points that develop in the muscles around a frozen shoulder, particularly the upper trapezius, infraspinatus, subscapularis and pectoralis minor. These muscles tighten as compensatory patterns develop around the restricted joint. Releasing them does not fix the capsular restriction itself, but it reduces surrounding muscle guarding, improves comfort and makes mobilisation and rehabilitation more effective.

Fascial release

Instrument-assisted soft tissue mobilisation helps address the fascial restrictions that develop throughout the shoulder girdle during months of restricted movement. The pectoral fascia, posterior capsule and surrounding connective tissue all stiffen when the shoulder is not moving normally. Releasing these restrictions complements the joint mobilisation work.

Targeted rehabilitation

This is the foundation of long-term improvement. Progressive exercise that respects the irritability of the shoulder while steadily working toward more range of motion and strength is essential. Research shows that structured stretching stimulates the body’s own tissue-remodelling processes within the capsule, helping to break down the fibrosis that causes stiffness (Kim et al., 2025).

Rehabilitation includes:

Pendulum exercises in the early, painful phase to maintain gentle movement without loading the joint
Passive and active-assisted stretching to gradually restore range of motion, particularly external rotation and overhead reach
Progressive strengthening of the rotator cuff and scapular stabilisers once range of motion allows
Functional movement retraining to address the compensatory patterns that developed while the shoulder was restricted

We prescribe exercises scaled to your stage and tolerance and progress them as you improve.

What about corticosteroid injections?

Corticosteroid injections can provide fast short-term pain relief, particularly during the freezing phase when pain is the primary problem. They can make a real difference to sleep and daily function during the worst of it.

However, the benefit tends to diminish over time, and injections do not address the capsular stiffness or the factors driving the condition (Page et al., 2014). They are a tool, not a solution. We refer for injections when pain is severe enough to prevent sleep or participation in rehabilitation, and then use the pain-relief window to accelerate the manual therapy and exercise programme. The combination of injection followed by active treatment produces better long-term outcomes than either approach alone.

When to get help

Do not wait months hoping it will sort itself out. The earlier you start appropriate treatment, the shorter the course and the better the outcome tends to be. See a professional if:

Your shoulder has been getting progressively stiffer over weeks or months
You cannot reach behind your back, fasten clothing or reach overhead
Shoulder pain is waking you at night
You have diabetes, thyroid problems or are going through menopause and have noticed shoulder stiffness developing
You have been told to “wait it out” but things are not improving

A proper assessment can distinguish frozen shoulder from rotator cuff injury, calcific tendonitis and other causes of shoulder pain, and get you on the right treatment path.

If your shoulder is stiffening up and not getting better, get in touch or book an appointment. We will work out what stage you are in and build a treatment plan around it.

References

FROZEN SHOULDER: WHY IT HAPPENS, WHO GETS IT AND HOW WE TREAT IT