1. Differential diagnosis of FS must be deliberate and active 

External rotation loss is the clue; everything else is noise. 

Frozen shoulder (FS) is a label we think we are confident about until the stiff shoulder in front of you does not behave like one. 

There are no universally accepted diagnostic criteria so diagnosis relies on pattern recognition plus sensible exclusion of red flags and masqueraders (Millar et al 2022, Rangan et al 2015). 

Onset is often insidious in primary FS but a ‘secondary’ FS presentation can follow trauma, surgery or prolonged relative immobilisation, which can be easier for patients (and referrers) to understand as a trigger (Millar et al 2022, Rangan et al 2015). 

Clinically, I look for a progressive story of pain followed by stiffness, with global restriction where active range is similar to passive range, and a clear loss of external rotation compared with the other side (Millar et al 2022). 

The trap is calling pain plus stiffness ‘frozen’ too early. 

Early presentations can mimic rotator cuff-related pain, calcific tendinopathy or glenohumeral osteoarthritis, particularly when pain is dominant (Millar et al 2022). 

Your job is to keep your differential diagnosis active: trauma, systemic symptoms, neurological signs, disproportionate weakness or an atypical end-feel should change your plan and trigger further investigation (Rangan et al 2015). 

Imaging is rarely about confirming FS. It is about excluding alternate pathology when the history or exam does not fit or when progress is unexpectedly poor (Rangan et al 2015). 

If ultrasound is requested, it can be useful to rule in supportive features when the clinical picture fits, such as capsular or axillary recess thickening, but it is still an adjunct rather than a standalone test (Millar et al 2022, Sernik et al 2019, Do et al 2021).

2. Stage and irritability should dictate FS mobilising 

Pain dominates first, so why are we mobilising like it is a stiffness problem? 

The most common clinical mistake I see is escalating stretching and mobilisation when the shoulder is clearly irritable. 

Early-stage FS is often characterised by night pain, pain at rest and high reactivity to testing and in that context aggressive end-range work can flare symptoms and stall momentum (Millar et al 2022). 

The evidence and clinical reality align here. In the early, painful stage, intensive physiotherapy does not consistently outperform a symptom-guided approach and irritability should drive dosing decisions (Challoumas et al 2020, Millar et al 2022). 

When irritability is high, I bias treatment towards pain-limited active or assisted range, low-grade joint mobilisation, graded exposure to functional movement and clear dosing rules that protect sleep and reduce flare-ups (Millar et al 2022). 

Strength matters but it is rarely the cornerstone in the painful, highly reactive phase. 

When irritability settles and stiffness is the main limiter, end-range mobilisation, sustained stretching and progressive strengthening become appropriate (Millar et al 2022). 

Patients rarely fail because they did not stretch enough – they fail because we flare them, they stop moving and guarding takes over.

3. FS prognosis is variable and beliefs can affect outcomes 

If your patient feels dismissed, you have already lost half the battle. 

‘It is self-limiting’ is the classic line about FS but this can be an unhelpful oversimplification. 

FS is often described as lasting one to three years, yet complete recovery is not guaranteed, with around half reporting ongoing symptoms years after onset (Brindisino et al 2026, Millar et al 2022). 

That uncertainty is exactly why your education either helps or harms. 

In clinic, the issues that derail progress are often not purely mechanical. 

Poor sleep, fear of movement, frustration and low confidence can amplify pain, reduce willingness to move and feed the stiffness and disability loop. 

Evidence links outcomes to specific psychological predictors – including kinesiophobia and baseline mental health – not just structural factors (Brindisino et al 2025, De Baets et al 2020). 

Two practical points I lean on: first, normalise the typical trajectory without promising deadlines and explicitly separate ‘pain-dominant’ from ‘stiffness-dominant’ presentations so patients understand why the plan changes over time (Millar et al 2022). 

Second, reframe ‘stiffness’ as a blend of central sensitisation and capsular restriction – not a simple stretching problem – acknowledging both peripheral and central pain contributions (Brindisino et al 2026, De Baets et al 2020). 

When patients feel heard and the plan makes sense, adherence and outcomes improve.

4. Early pain control can unlock better FS rehab 

Supervised neglect or aggressive physiotherapy? 

The truth is stage dependent. 

Early pain control is not giving up on rehab. It can be the gateway to sleep, movement and confidence, which is why corticosteroid injection is commonly recommended early in irritable presentations, alongside appropriately dosed physiotherapy (Millar et al 2022). 

Hydrodilatation is worth understanding properly. It aims to distend the capsule using a higher-volume intra-articular injection, often with local anaesthetic and corticosteroid (Poku et al 2023). 

Metaanalytic evidence positions hydrodilatation with corticosteroids as the most effective conservative option, with the clearest gains in the short term, though it is not a standalone fix (Lädermann et al 2021, Poku et al 2023). 

The nuance is what happens next. 

After hydrodilatation, a clear home program can perform similarly to supervised physiotherapy, so the key is dosing, progression and accountability, not simply more sessions (Robinson et al 2017). 

Emerging trial evidence also supports combined approaches (hydrodilatation plus injection plus mobilisation and physiotherapy) over physiotherapy alone in some cohorts (Huang et al 2024). 

Clinically, I treat the days after injection as a window of opportunity to reset expectations, reinforce safe movement and build a simple plan the patient can stick to.

5. Escalation decisions in FS should be shared and staged 

The UK FROST trial did not give us a winner; it gave us a smarter conversation. 

Escalation is not failure. It is a step in the pathway for the subgroup who are not progressing despite well-staged care. 

There are no strict evidence-based rules for the perfect time to intervene, so shared decision-making matters (Millar et al 2022). 

The UK FROST trial provides a useful anchor: early structured physiotherapy (with steroid injection), manipulation under anaesthetic and arthroscopic capsular release all showed substantial improvement by 12 months, with no single clear ‘winner’ (Rangan et al 2020). 

Arthroscopic capsular release may offer slightly better outcomes on some measures but remains more invasive and costly, typically reserved for those who fail less invasive options (Rangan et al 2020). 

In clinic, the ‘who’ matters more than the ‘which’. 

If someone remains highly disabled, cannot sleep and is not trending in the right direction despite stageappropriate care, raise escalation options early. 

Add metabolic risk factors – diabetes or thyroid disease – and the threshold for referral often drops (Millar et al 2022).

>>Ben Onofrio MACP is an APA Titled Sports and Exercise Physiotherapist and an APA Titled Musculoskeletal Physiotherapist. Ben works at Wakefield Sports and Exercise Medicine Clinic in Adelaide, focusing on shoulder assessment and rehabilitation. He is a clinical educator at Adelaide University and runs workshops through Simple Shoulder Systems. Ben is a member of the APA Musculoskeletal national group.

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