If you've had on-again, off-again shoulder pain for months — the kind that flares with overhead pressing, settles down for a few weeks, then comes back — you've probably been told it's "rotator cuff." That's not wrong, exactly. But it's incomplete in a way that matters for how you recover.

The 2018 BJSM consensus paper by Jeremy Lewis introduced (and the field largely adopted) the term "rotator cuff related shoulder pain" instead of impingement or subacromial syndrome. It's a deliberately broader label — because the evidence is now clear that the rotator cuff is rarely the only problem.

What the CSAW trial showed

The CSAW (Can Shoulder Arthroscopy Work?) trial published in The Lancet (Beard et al., 2018) randomized patients with subacromial shoulder pain into three groups: arthroscopic decompression surgery, sham surgery, or no surgery. The result: no meaningful difference between the three at one year.

That's striking. The structural finding (a tight subacromial space) that we'd long blamed for shoulder pain didn't, when fixed, produce better outcomes than doing nothing. The shoulder doesn't seem to read its own MRI.

“The shoulder doesn't read its own MRI.”

So what's actually driving chronic shoulder pain?

Three contributors keep showing up in the literature on rotator cuff related pain:

1. Capacity — the rotator cuff is undertrained for its job

The rotator cuff is a tendon system. Like all tendons, it responds to progressive load — and badly to underloading. Most chronic shoulder pain involves a cuff that has lost the strength and endurance to control the head of the humerus under load. The solution is, predictably, structured loading.

2. Scapular control — the upstream limitation

The scapula is the platform the cuff works from. If the scapula doesn't move well (limited upward rotation, posterior tilt, or controlled retraction), the cuff is asked to work in a mechanical disadvantage on every overhead movement. Targeted scapular work changes shoulder mechanics measurably.

3. Thoracic spine mobility

The shoulder needs thoracic extension and rotation to reach overhead well. If your thoracic spine is stiff (common in desk workers, lifters who don't mobilize, post-injury patterns), the shoulder borrows range it doesn't have — and the cuff pays the bill.

What progressive loading actually looks like

Shoulder rehab follows the same logic as other tendon-related care:

  1. Isometric phase. Holds against resistance in pain-free or low-pain positions. Useful for pain modulation early on.
  2. Heavy slow resistance. External rotation, abduction, scaption with progressive load. 3-second tempos. 2–3 sessions per week.
  3. Compound shoulder strength. Pressing, pulling, carries — loading the shoulder in functional patterns.
  4. Sport or task-specific loading. Throwing, swimming, overhead lifting, manual labor demands.

A Cochrane review (Page et al., 2016) and multiple subsequent meta-analyses support exercise as first-line care, with manual therapy as a useful adjunct.

Shoulder pain that won't quit?

An assessment can identify which of the three contributors is driving yours — and build the plan that addresses it.

Book an Assessment →

What about imaging findings?

This is important. MRI findings of rotator cuff "pathology" are extremely common in asymptomatic shoulders. Frank et al. (Am J Sports Med, 2018) and earlier work by Tempelhof showed that age-related cuff changes — including partial-thickness tears — are present in a high percentage of pain-free shoulders.

The takeaway: your MRI is a snapshot of structure, not a diagnosis of your pain. A radiology report is useful clinical information, but it has to be interpreted alongside what your shoulder is actually doing functionally.

When surgery is genuinely indicated

For specific traumatic full-thickness tears in younger or higher-demand patients, surgical repair has a role. For most atraumatic or chronic rotator cuff related pain in middle-aged and older adults, exercise-led care produces outcomes comparable to surgery (Kuhn et al., MOON Shoulder Group). The decision is individualized.

Bottom line

Chronic shoulder pain is almost never just the rotator cuff. It's a combination of cuff capacity, scapular control, and thoracic mobility — and the path back involves loading all three, not chasing the symptom. Imaging findings often don't change the rehab plan. Surgery has a specific role; exercise has the bigger one.

References

  1. Lewis J. Rotator cuff related shoulder pain: Assessment, management and uncertainties. Man Ther. 2016;23:57–68. / Lewis et al., BJSM 2018 consensus.
  2. Beard DJ, et al. Arthroscopic subacromial decompression for subacromial shoulder pain (CSAW). Lancet. 2018;391(10118):329–338.
  3. Page MJ, et al. Manual therapy and exercise for rotator cuff disease. Cochrane Database Syst Rev. 2016;6:CD012224.
  4. Kuhn JE, et al. Effectiveness of physical therapy in treating atraumatic full-thickness rotator cuff tears. MOON Shoulder Group. J Shoulder Elbow Surg. 2013;22(10):1371–1379.