Mobilization with movement plus exercise versus exercise alone for central sensitization in chronic subacromial pain syndrome: a sham-controlled RCT

Key points

1. 01No short-term (post-3-week) advantage of MWM over sham or exercise alone on any outcome measure
2. 02At 3 months, MWM group showed significantly higher pressure pain thresholds at deltoid, brachioradialis, rectus femoris, and tibialis anterior compared to both control groups
3. 03Central Sensitization Inventory scores and disability (QuickDASH) did not differ significantly between groups at either time point
4. 04Sham hand contact alone may have neurophysiological effects on central sensitization, complicating interpretation
5. 05Central sensitization score correlated significantly with widespread mechanical hyperalgesia and upper limb disability at follow-up

How it was conducted

Design

3-arm parallel-group, assessor-blinded, sham-controlled randomized trial (CONSORT-compliant)

Participants

63 patients with central sensitization associated with chronic subacromial pain syndrome, aged under 65, symptom duration over 3 months, CSI score indicating moderate-or-higher central sensitization

Groups

MWM plus exercise (n=21), sham-MWM plus exercise (n=21), exercise alone/control (n=21)

Intervention

15 exercise sessions over 3 weeks (5/week); MWM or sham applied 3 sessions/week (3 sets of 10 reps each session)

Primary outcomes

Central Sensitization Inventory (CSI) score and pressure pain threshold (PPT) at deltoid, brachioradialis, rectus femoris, and tibialis anterior

Follow-up

Baseline, post-intervention (3 weeks), and 3 months post-intervention

What they found

• Significant group x time interaction for PPT at deltoid (F=2.769, p=0.033, partial eta-squared=0.122), brachioradialis (F=4.319, p=0.003, partial eta-squared=0.178), rectus femoris (F=3.230, p=0.022, partial eta-squared=0.139), and tibialis anterior (F=2.661, p=0.039, partial eta-squared=0.117)
• No significant group x time interaction for CSI score (F=1.231, p=0.305) or QuickDASH (F=1.675, p=0.113)
• At 3-month follow-up, MWM vs sham-MWM: PPT-deltoid MD 0.6 kg/cm2 (95% CI 0.0 to 1.2), PPT-brachioradialis MD 0.9 kg/cm2 (95% CI 0.1 to 1.7, p=0.028), PPT-rectus femoris MD 0.9 kg/cm2 (95% CI 0.2 to 1.8, p=0.008), PPT-tibialis anterior MD 0.7 kg/cm2 (95% CI 0.1 to 1.4, p=0.029)
• At 3-month follow-up, MWM vs control: PPT-deltoid MD 1.0 kg/cm2 (95% CI 0.4 to 1.5, p<0.001), PPT-brachioradialis MD 1.0 kg/cm2 (95% CI 0.2 to 1.8, p=0.012), PPT-rectus femoris MD 0.9 kg/cm2 (95% CI 0.3 to 1.6, p=0.005), PPT-tibialis anterior MD 0.8 kg/cm2 (95% CI 0.1 to 1.5, p=0.022)
• No significant between-group differences at post-intervention for any outcome (p>0.05 for all)
• 6 patients lost to follow-up: 3 MWM, 1 sham-MWM, 2 control; per-protocol analysis on 57 patients
• James Blinding Index 0.6 (95% CI 0.168 to 0.839), indicating successful blinding of participants

Limitations

• Quantitative Sensory Testing - the gold standard for central sensitization assessment - was not used
• Strict exclusion criteria improve internal validity but limit generalizability to broader subacromial pain syndrome populations with central sensitization
• Sample skewed toward lower educational backgrounds due to selective dropout during recruitment, limiting generalizability
• No long-term follow-up beyond 3 months; durability of mid-term benefits is unknown

Why it matters

For patients

Patients with chronic shoulder pain and signs of central sensitization may gain greater pain sensitivity benefits from MWM added to their exercise program, but should not expect faster short-term symptom relief compared to exercise alone.

For clinicians

MWM can be considered an adjunct to exercise for reducing widespread mechanical hyperalgesia over the medium term, but its short-term neurophysiological effects may be partly replicated by therapeutic touch alone, and it does not appear to change subjective central sensitization symptoms or arm disability scores.

For readers

This is the first RCT to examine MWM effects specifically on central sensitization in subacromial pain syndrome, filling a gap in manual therapy evidence, though the small sample and 3-month horizon call for cautious interpretation.