Few shoulder problems come with as much hearsay as frozen shoulder. It freezes, it stays frozen and then it thaws, which can take a while, and the advice is often little more than patience.
The trouble is that the hearsay is not the best advice. Researchers who looked at whether frozen shoulder resolves on its own found that people do improve over time, but many of them never get all of their movement back.
That should change what we tell our clients. Waiting is not much of a plan, and the research gives us a better one.
What Frozen Shoulder Is
Frozen shoulder, also called adhesive capsulitis, is a condition in which the capsule around the shoulder joint becomes inflamed and tightens. A group of shoulder specialists led from the University of Glasgow describe it as a common and debilitating disorder marked by shoulder pain and a progressive loss of movement (Millar et al., 2022).
Inside the joint, cells called fibroblasts change into a more contractile type and lay down extra collagen. New blood vessels and nerve endings grow into the tissue. The result is a capsule that is both painful and physically smaller, which is why the joint feels stiff.
The result is a loss of movement in every direction, but especially external rotation, the movement of turning the forearm outwards with the elbow tucked in at your side. Reaching behind the back to tuck in a shirt or fasten a bra becomes difficult, and so does reaching up to a high shelf.
Most cases don’t seem to have an obvious cause. Others follow a period when the arm has been kept still, for example after a fracture, surgery or a bout of illness.
Who Gets It
Frozen shoulder is usually estimated to affect somewhere between two and five per cent of the population at some point in their lives. It turns up most often between the ages of about 40 and 60, and it is more common in women.
Diabetes is the clearest risk factor. A meta-analysis from Keele University pooled six case-control studies including 5,388 people and found that the odds of developing frozen shoulder were almost four times higher in people with diabetes (Dyer et al., 2023). Two cohort studies that followed people over time pointed in the same direction, with smaller but still clear increases in risk.
Thyroid disease and other metabolic conditions are also linked with it in clinical literature, although the evidence is not as definite.
For us, the profile is common. A woman in her fifties, perhaps going through menopause, perhaps managing type 2 diabetes, who comes to us because she has lost confidence in her shoulder and wants to stay active.
Living With a Frozen Shoulder
It is easy to underestimate how much a frozen shoulder affects someone. The pain is often worst at night, especially when lying on the affected side, and clients come to us already tired after weeks of broken sleep.
Everyday tasks become awkward. Washing hair, putting on a coat, reaching for a seatbelt and lifting a child or grandchild can all become difficult or painful. Clients often start using the other arm for everything without realising it.
Training usually suffers too. Pressing and anything overhead may be impossible, and many people simply stop going to the gym because they do not know what they can or should do. Losing that routine can feel like a big loss to a client, especially when it comes on top of the other changes of midlife.
So the first thing many of these clients need from a coach is a plan. Showing them what they can still train, and how the frozen shoulder can be included in the programme, can be very reassuring.
The Three Stages Story
The classic description of frozen shoulder goes back to the 1940s. It states it moves through a painful freezing phase, a stiff frozen phase and a recovery thawing phase, ending in full recovery without treatment.
A systematic review set out to test that storyline directly (Wong et al., 2017). The researchers looked only at studies where some people received no treatment at all and were followed for at least six months.
Low-quality evidence suggested that people who had no treatment did get some improvement over one to four years, but not complete recovery. There was no evidence that people moved neatly through the phases to full resolution. Moderate-quality evidence from three trials showed that most of the improvement happened early, not late.
The authors were clear that the idea of recovery phases leading to complete resolution without treatment is unfounded. That does not make the three stages useless as a description. It does make them a poor reason to advise a client to sit and wait.
What Treatment Works Best
So if waiting is not the answer, what is? A large network meta-analysis from the University of Glasgow compared every treatment option they could find, across 65 studies and more than 4,000 participants (Challoumas et al., 2020).
Only one treatment stood out on its own in the short term, and that was a steroid injection into the shoulder joint, which beat physiotherapy and placebo for both pain and function. The researchers then found that adding a home exercise programme of simple exercises and stretches, with or without physiotherapy, may bring further benefit over the following months.
Their recommendation was that an early steroid injection in people who have had frozen shoulder for less than a year should be accompanied by a home exercise programme to give the best chance of recovery.
An injection can calm things down. Exercise is what gets the shoulder moving again.
Surgery or Physiotherapy
The most important UK trial on frozen shoulder is UK FROST, run across 35 hospitals and published in The Lancet (Rangan et al., 2020).
It recruited 503 adults who had been referred to secondary care with frozen shoulder and at least a 50 per cent loss of passive external rotation. They were randomly assigned to one of three treatments. Two were operations under general anaesthetic: manipulation of the shoulder to stretch and tear the tight capsule, or keyhole surgery to cut through it. The third was early structured physiotherapy, made up of hands-on mobilisation and a graduated home exercise programme, alongside a steroid injection.
At 12 months, all three groups had improved by a similar amount. Scores on the 48-point Oxford Shoulder Score were 40.3 for keyhole surgery, 38.3 for manipulation and 37.2 for physiotherapy, and none of the differences was large enough to count as clinically superior. Keyhole surgery came with more serious adverse events.
For clients, this tells us that a structured, exercise-based approach is a serious treatment in its own right, and for many people may very well be the main one.
What Kind of Exercise Helps
Knowing exercise helps is one thing. Knowing which kind is another.
A meta-analysis from the University of Antwerp pooled the trials on exercise therapy for frozen shoulder (Mertens et al., 2022). Range of movement and function improved with exercise, and so did pain. There was early evidence that supervised exercise beat exercise done alone at home for range and function, and that adding stretching to a broader programme may increase range further.
Adding exercises to a programme improved active range compared with a programme without them, while adding physical modalities such as heat or electrotherapy brought no extra benefit. The authors could not say what the best long-term dose was, which is not uncommon.
Two practical points include that supervision helps, which suits a coach who sees a client regularly. And exercise is the active ingredient, so there is little reason to have passive treatments in the sessions.
Respect the Pain Early
How you train a frozen shoulder depends heavily on how irritable it is. In the early, painful stage, the shoulder can be sore at rest and at night, and pushing hard into the stiff range usually makes things worse.
At this point, the goal is to keep the shoulder moving gently within a comfortable range, keep the rest of the body training and support the client while the clinical team manages the pain. Pendulum swings, supported reaching on a table, gentle rotation with a stick or towel and walking all have a place. A small amount of discomfort that settles quickly is fine. Pain that lingers into the evening or the next morning is a sign it’s been trained too hard, so back off.
This is also the stage when clients most need reassurance. Many will have been told it could take years, and they may have stopped training altogether. Keeping them in the gym, working on everything else, protects their fitness and their mood.
Load the Stiff Shoulder Later
As the pain settles and stiffness becomes the main complaint, the approach changes. Now the shoulder can tolerate more, and the aim is to steadily reclaim range and strength in the range that comes back.
Longer, firmer stretches into external rotation and overhead reaching become useful. So does active work at the end of the available range, because a shoulder that can only reach a position when pushed is not much use. Light rotator cuff work, rows and controlled pressing within the available range help build the strength through the range that’s gained.
This is the gap between passive and active range in action. A client may be able to let you move their arm to a certain point, but struggle to lift it there themselves. Closing that gap should be our aim.
A simple external rotation progression test will give you a good indication of where your client is at. Start with the client lying on their back, elbow tucked in and supported on a folded towel, gently rotating the forearm outwards with a stick in both hands so the good arm helps. Move on to doing the same movement without help, then standing with a light band, and finally with the arm out to the side at shoulder height. Each step asks the client to control a little more range on their own.
Progress tends to come in small steps over months. Measure it in ways the client can understand simply, such as reaching a high shelf, doing up a zip or sleeping through the night.
Keep Everything Else Strong
Another useful thing we can do for a client with frozen shoulder is to keep the rest of their body training, as it protects their fitness and their routine while the shoulder recovers.
Lower body strength work can carry on almost as normal. Squats, lunges, step-ups, hip hinges with a kettlebell or trap bar and leg press all work well, as long as the client can hold or position the load comfortably. Single-arm work on the unaffected side fills out the strength work. Cardiovascular training and core work that does not load the painful shoulder can all be completed as normal.
It also helps with mood. A client who can still see progress in the gym, even while one arm is restricted, is far more likely to stick with their shoulder mobility exercises too.
A Coaching Guide by Stage
The table below gives a simple guide to adjusting training as frozen shoulder changes over time. Always work alongside the client’s GP or physiotherapist, and take their lead on the treatment plan.
| Stage | What the Client Usually Notices | How to Train |
|---|---|---|
| Painful (freezing) | Pain at rest and at night, movement increasingly restricted | Gentle movement within comfort, keep the rest of the body training, avoid forcing range |
| Stiff (frozen) | Pain easing but movement very limited, especially rotation | Firmer stretches, active work at end range, light strengthening in the available range |
| Recovering (thawing) | Range slowly returning, less pain | Progressive strength through the new range, overhead and rotational work, return to normal training |
| Any stage, worse after training | Pain lasting into the evening or next day | Reduce range or load and progress more gradually |
When to Refer
Remember, as a personal trainer, we should never diagnose frozen shoulder. Several other conditions cause a painful, stiff shoulder, including rotator cuff tears, arthritis of the shoulder joint and problems referred from the neck.
Refer a client to their GP if their shoulder pain followed a fall or injury, if they have marked weakness rather than stiffness, or if the pain is severe and constant. Shoulder pain with chest pain, breathlessness or sweating needs urgent medical attention. Unexplained weight loss, fever or a history of cancer alongside new shoulder pain also needs checking.
If a client already has a diagnosis and a treatment plan, ask what their physiotherapist wants them to focus on, and keep your programme in line with it. With the client’s permission, a short message to their physiotherapist explaining what you are doing in the gym makes it far easier to work as a team. It also gives them a fuller picture of how their patient is getting on between appointments, which is useful when recovery stretches over many months.
Bringing It Into Your Coaching
Many of us find our clients have been told that frozen shoulder is something to be patient with, and wait. The research however, gives us a more hopeful and more active message.
Frozen shoulder is common, especially in women in midlife and people with diabetes. It does not reliably resolve on its own, and the most improvement tends to come early on. Structured exercise, often alongside a steroid injection, performs as well as surgery for many people. And supervised exercise appears to beat doing it alone at home.
That puts a skilled coach in a strong position. You can keep a client training through the painful stage, help them reclaim and strengthen their range as the stiffness eases, and give them the confidence to use their shoulder again.
And the skills that get a frozen shoulder moving are the same ones that help every client move better. Understanding range, stiffness and how to load a joint through its full available range of movement is not only useful for frozen shoulder, but all types of activity a client may be involved in.
References
Challoumas, D., Biddle, M., McLean, M. and Millar, N.L. (2020). Comparison of treatments for frozen shoulder: a systematic review and meta-analysis. JAMA Network Open, 3(12), e2029581. Click here to review the full research article.
Dyer, B.P., Rathod-Mistry, T., Burton, C., van der Windt, D. and Bucknall, M. (2023). Diabetes as a risk factor for the onset of frozen shoulder: a systematic review and meta-analysis. BMJ Open, 13(1), e062377. Click here to review the full research article.
Mertens, M.G., Meert, L., Struyf, F., Schwank, A. and Meeus, M. (2022). Exercise therapy is effective for improvement in range of motion, function, and pain in patients with frozen shoulder: a systematic review and meta-analysis. Archives of Physical Medicine and Rehabilitation, 103(5), pp.998-1012. Click here to review the full research article.
Millar, N.L., Meakins, A., Struyf, F., Willmore, E., Campbell, A.L., Kirwan, P.D., Akbar, M., Moore, L., Ronquillo, J.C., Murrell, G.A.C. and Rodeo, S.A. (2022). Frozen shoulder. Nature Reviews Disease Primers, 8(1), 59. Click here to review the full research article.
Rangan, A., Brealey, S.D., Keding, A., Corbacho, B., Northgraves, M., Kottam, L., Goodchild, L., Srikesavan, C., Rex, S., Charalambous, C.P., Hanchard, N., Armstrong, A., Brooksbank, A., Carr, A., Cooper, C., Dias, J.J., Donnelly, I., Hewitt, C., Lamb, S.E., McDaid, C., Richardson, G., Rodgers, S., Sharp, E., Spencer, S., Torgerson, D., Toye, F. and UK FROST Study Group (2020). Management of adults with primary frozen shoulder in secondary care (UK FROST): a multicentre, pragmatic, three-arm, superiority randomised clinical trial. The Lancet, 396(10256), pp.977-989. Click here to review the full research article.
Wong, C.K., Levine, W.N., Deo, K., Kesting, R.S., Mercer, E.A., Schram, G.A. and Strang, B.L. (2017). Natural history of frozen shoulder: fact or fiction? A systematic review. Physiotherapy, 103(1), pp.40-47. Click here to review the full research article.
Get Stiff Shoulders Moving Again
A frozen shoulder is one of the clearest examples of the gap between the range a joint can be pushed into and the range a client can control. Closing that gap is a skill, and it applies to every stiff joint you will ever coach.
Our new Movement & Mobility Course teaches you how the nervous system controls stiffness, how to assess range joint by joint and how to programme to close the passive-to-active range gap. It gives you the confidence to work with stiff, sore and cautious clients, and a clear plan for helping them move well again.
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Movement & Mobility Course – Distance Study
