Effects of a traditional versus an alternative strengthening exercise program on shoulder pain, function and physical performance in individuals with subacromial shoulder pain: a randomized controlled trial

Key points

1. 01Both training groups improved pain, flexibility, strength, and endurance versus a passive control group
2. 02The device-assisted group (ALT) achieved a 51% improvement in SPADI total score versus 28% in the traditional group
3. 03Only the ALT group exceeded the minimal clinically important difference of 13.2 points on SPADI (20.0 points vs 12.7 points)
4. 04ALT training produced larger range-of-motion gains in both external and internal shoulder rotation
5. 05ALT group showed a 35% reduction in nocturnal shoulder pain; the traditional group showed no reduction

How it was conducted

Design

Three-arm randomized controlled trial with pre- and post-testing

Participants

56 adults (completers) with diagnosed subacromial shoulder pain for at least 1 year, aged 35-65

Groups

Passive control (CON, n=20); traditional elastic band training (TRA, n=19); alternative device-assisted training (ALT, n=17)

Intervention

8-week home-based progressive external rotation exercise, 3 sessions/week, 7 sets per session, with or without the Schulterhilfe manual shoulder device

Primary outcome

Shoulder Pain and Disability Index (SPADI) total and subscale scores (0-100)

Secondary outcomes

Shoulder ROM (goniometry), maximal isometric strength (force transducer), strength endurance (CKCUEST and metronome-paced test)

What they found

• SPADI total score improvement: ALT +51% (p<0.001, d=0.98), TRA +28% (p=0.002, d=0.64), CON +4% (not significant)
• SPADI disability subscale: ALT +58% (p<0.001, d=0.89), TRA +24% (p=0.004, d=0.54)
• SPADI pain subscale: ALT +44% (p<0.001, d=0.91), TRA +27% (p=0.002, d=0.75)
• ALT absolute SPADI improvement of 20.0 points exceeded the MCID of 13.2 points; TRA improvement of 12.7 points fell 0.5 points short
• ROM external rotation left arm: ALT +28% (p<0.001, d=1.13), TRA +18% (p=0.003, d=0.75)
• ROM internal rotation right arm: ALT +57% (p<0.001, d=1.00), TRA +41% (p=0.014, d=0.53)
• ROM external rotation right arm: ALT +17% (p=0.003, d=0.93), TRA +6% (p=0.207, d=0.27, not significant)
• Maximal isometric strength external rotators right arm: ALT +54% (p<0.001, d=0.88), TRA +42% (p<0.001, d=0.46)
• Metronome-paced strength endurance: ALT +89% (p=0.012, d=0.94), TRA +23% (p=0.665, d=0.08, not significant)
• CKCUEST: TRA +19% (p=0.001, d=1.00), ALT +14% (p<0.001, d=0.66)
• Nocturnal shoulder pain prevalence change: ALT -35%, TRA +5%, CON 0%

Limitations

• No follow-up assessment beyond 8 weeks, so long-term and attenuation effects are unknown
• Maximal isometric strength was measured at 90-degree abduction, which mirrors the ALT training position but not the TRA position (0-degree abduction), potentially biasing strength results in favor of ALT
• The metronome-paced endurance test replicated the ALT exercise exactly, which may have inflated ALT endurance results
• Study was funded by the device manufacturer (AktiFlex Produkte KG), raising potential conflict-of-interest concerns even though funders reportedly had no role in data analysis

Why it matters

For patients

People with chronic subacromial shoulder pain can achieve clinically meaningful pain relief and improved daily function in 8 weeks using a simple home exercise with a low-cost shoulder device, without needing supervised clinic visits.

For clinicians

When prescribing home exercise for subacromial shoulder pain, adding the Schulterhilfe device to elastic band external rotation training produces larger and more clinically important SPADI improvements than bands alone and may be worth recommending as a cost-effective adjunct.

For readers

This RCT provides moderate evidence that device-assisted external rotation exercise is superior to standard elastic band exercise for subacromial shoulder pain, though manufacturer funding and the absence of long-term follow-up limit the strength of conclusions.