Glenn Wellmann DPT

Frozen shoulder starts as an annoyance and becomes the thing that defines your year. It usually begins with a deep ache on the outside of the shoulder that is worst at night, and over weeks or months the arm quietly stops going places. Reaching a seatbelt, a back pocket, or the top of your head all become negotiations.

The medical name is adhesive capsulitis. The capsule, the sleeve of connective tissue wrapping the ball and socket joint, becomes inflamed and then thickens and contracts. It is not a muscle tightness problem you can stretch out in a week, and it is not a rotator cuff tear. The distinguishing feature is that both active and passive motion are limited: it does not matter whether you lift the arm or someone lifts it for you, it stops in the same place. Turning the arm outward is usually the most restricted direction.

In the clinic I see this most often in people between 40 and 60, more often in women, and disproportionately in people with diabetes or thyroid disease. It can also follow a stretch of not using the arm after an injury or surgery.

Why it gets described in three phases

You have probably read that frozen shoulder moves through freezing, frozen, and thawing. That framework is genuinely useful for deciding what to do, and I use it every week. It deserves one important asterisk, which I come back to below.

1. Freezing, roughly the first 2 to 9 months. Pain leads, often worse at night, and motion is being lost faster than you can keep up with. This is the irritable phase.
2. Frozen, roughly 4 to 12 months. Pain settles and stiffness takes over. The shoulder hurts less at rest but will not go where you send it. This is where people get frustrated, because it feels stable but useless.
3. Thawing, roughly 12 to 24 months or longer. Motion gradually returns. Progress feels slow but real.

Timelines vary a lot, so treat those ranges as a rough map, not a schedule. What matters more than the label is which problem is in charge right now: pain or stiffness. Physical therapists grade that formally as irritability, from high to low, and build the plan around it (Kelley et al., Journal of Orthopaedic and Sports Physical Therapy, 2009). The same framework anchors the clinical practice guideline for shoulder pain and mobility deficits (Kelley et al., Journal of Orthopaedic and Sports Physical Therapy, 2013).

What the evidence actually says about the asterisk

Here is the part that surprises people. The comforting version of the three phases is that you can wait it out and it will fully resolve on its own. A systematic review examined that claim and did not find support for it. Across seven studies with at least six months of follow-up, low-quality evidence suggested no treatment produced some, but not complete, improvement in range of motion after 1 to 4 years, and moderate-quality evidence from three randomized trials showed most improvement happened early rather than late. The authors called the idea of progressing through the phases to complete resolution without treatment unfounded (Wong et al., Physiotherapy, 2017). Use the phases to decide what to do now, not as a reason to do nothing for two years.

The second thing worth knowing sits at the other end of the spectrum, when people go looking for a surgical fix. The UK FROST trial randomized 503 adults with primary frozen shoulder across 35 UK hospitals to manipulation under anaesthesia, arthroscopic capsular release, or early structured physiotherapy. Mean scores at 12 months were 38.3 for manipulation, 40.3 for capsular release, and 37.2 for physiotherapy, on a 0 to 48 scale. Every between-group difference came in under the target the researchers had set as worthwhile, and the authors concluded that none of the three was clinically superior, that capsular release carried higher risks, and that manipulation was the most cost-effective (Rangan et al., The Lancet, 2020). Structured therapy is a reasonable first line, not a consolation prize.

What helps in each phase

Same condition, three different plans. The most common mistake I see is running phase-two treatment during phase one: aggressive stretching into a hot, irritable shoulder, which reliably makes the next two weeks worse.

Phase 1, pain dominant. Goal: calm it down and protect the motion you still have.

• Pendulum swings, 1 to 2 minutes, 3 to 5 times a day. Lean forward with the hand hanging and let the arm swing in small circles using body movement, not shoulder muscles.
• Pain-free range only. Move to where you feel a stretch, not where the ache spikes. If soreness lasts over an hour afterward, you went too far.
• Sleep setup. Lie on the other side with a pillow supporting the sore arm in front of you, or on your back with a folded towel under the elbow.
• Keep the rest of the arm working. Grip, elbow, and shoulder blade squeezes cost you nothing and preserve function.
• Ask about a guided injection if pain is unrelenting. In a 2024 randomized trial of 70 patients in the painful early stage, adding hydrodilatation, a corticosteroid injection and joint mobilization to physical therapy beat physical therapy alone on pain, disability and range of motion, with the difference holding at six months (Huang et al., Archives of Physical Medicine and Rehabilitation, 2024). Note that the winning group also did all the usual therapy.

Phase 2, stiffness dominant. Goal: earn range back, then hold it.

• Longer holds, more often. Sustained stretches of 30 to 60 seconds, 3 to 5 repetitions per direction, once or twice daily, now taking the shoulder to the end of its range.
• Prioritize turning the arm outward. On your back, elbow tucked at your side and bent to 90 degrees, let the forearm lower outward toward the floor. This is usually the most limited direction and the one that unlocks daily tasks.
• Add overhead in a supported position. On your back, use the good arm or a stick to guide the affected arm overhead so gravity works with you.
• This is where hands-on joint mobilization earns its keep. A therapist can move the joint in directions you cannot produce yourself, and you consolidate that gain at home.
• Start loading. Light rows, banded outward rotation, and shrug-free reaching, staying inside your comfortable range.

Phase 3, thawing. Goal: convert range into strength and stop protecting the arm.

• Strength work through the range you have regained. Two to three sessions a week, 2 to 3 sets of 8 to 12 reps, progressing load as tolerated.
• Reintroduce real tasks. Overhead lifting, carrying, reaching behind your back, sport-specific patterns. The arm has learned to avoid positions and needs teaching otherwise.
• Progress on criteria, not the calendar. This is the same logic I laid out in my post on a criteria-based progressive shoulder exercise program: you advance when the shoulder meets a standard, not when a set number of weeks has passed.
• Keep going after it feels normal. Involvement of the other shoulder is not rare, so maintaining full motion and strength is worth the ten minutes.

Red flags: when to get it looked at in person

• Stiffness that started with a fall, dislocation, or direct blow rather than gradually. That needs imaging first.
• Sudden inability to lift the arm at all, especially with visible muscle wasting, which can indicate a tendon or nerve problem rather than a capsule problem.
• Fever, redness, warmth over the joint, or feeling systemically unwell.
• Unexplained weight loss, night pain unrelated to position, or a history of cancer.
• Numbness, tingling, or weakness running down the arm into your hand.
• No improvement at all after three months of consistent, appropriately staged work.

One more thing to raise with your physician: if you have diabetes, frozen shoulder tends to be more stubborn, and blood sugar control is part of the picture.

Get the stage right before you pick the plan

Almost every frozen shoulder mistake I see traces back to treating the wrong phase: stretching hard into an irritable shoulder, or babying a stiff one that is ready for load. Sorting that out takes a proper exam and measured range of motion in each direction. If your shoulder has been locking up for months, a comprehensive evaluation gives you a full hour, real measurements, and a staged plan you leave with. If you already know your phase and just want the right progressions, a home exercise program is the leaner option.

References

• Kelley MJ, McClure PW, Leggin BG. Frozen shoulder: evidence and a proposed model guiding rehabilitation. Journal of Orthopaedic and Sports Physical Therapy. 2009;39(2):135-148. doi:10.2519/jospt.2009.2916. https://pubmed.ncbi.nlm.nih.gov/19194024/
• Kelley MJ, Shaffer MA, Kuhn JE, et al. Shoulder pain and mobility deficits: adhesive capsulitis. Journal of Orthopaedic and Sports Physical Therapy. 2013;43(5):A1-31. doi:10.2519/jospt.2013.0302. https://pubmed.ncbi.nlm.nih.gov/23636125/
• Wong CK, Levine WN, Deo K, et al. Natural history of frozen shoulder: fact or fiction? A systematic review. Physiotherapy. 2017;103(1):40-47. doi:10.1016/j.physio.2016.05.009. https://pubmed.ncbi.nlm.nih.gov/27641499/
• Rangan A, Brealey SD, Keding A, et al. Management of adults with primary frozen shoulder in secondary care (UK FROST): a multicentre, pragmatic, three-arm, superiority randomised clinical trial. The Lancet. 2020;396(10256):977-989. doi:10.1016/S0140-6736(20)31965-6. https://pubmed.ncbi.nlm.nih.gov/33010843/
• Huang YH, Kuo YC, Hsieh LF, Tsai CM, Liu YF, Hsieh TL. Efficacy of Combination Therapy (Hydrodilatation and Subdeltoid Bursa Injection With Corticosteroid, Mobilization, and Physical Therapy) vs Physical Therapy Alone for Treating Frozen Shoulder. Archives of Physical Medicine and Rehabilitation. 2024;105(4):631-638. https://pubmed.ncbi.nlm.nih.gov/38092231/