R. Kinsella1,2, S. Cowan1, L. Watson3, T. Pizzari1
1La Trobe University, La Trobe Sport and Exercise Medicine Research Centre, Melbourne, Australia, 2St Vincent's Hospital Melbourne, Physiotherapy, Melbourne, Australia, 3Melbourne Shoulder Group, Melbourne, Australia

Background: Subacromial pain syndrome (SPS) involving rotator cuff tendinopathy is a common cause of shoulder pain and disability. Structured exercise is effective in the management of SPS with significant improvements observed in trials involving scapular retraining and rotator cuff strengthening. It is not known whether varying the mode of contraction during rotator cuff strengthening exercises improves outcomes in this condition.  

Purpose: The primary aim of this pilot study was to determine the feasibility of undertaking a large randomised controlled trial (RCT) comparing the effects of different types of rotator cuff contractions (isometric, concentric and eccentric) when used as part of a semi-standardised program in participants with SPS. The secondary aim was to observe treatment effects, to explore whether greater improvements in pain, strength or function were achieved from either of the three interventions being investigated.

Methods: Diagnosis of SPS is complex with volunteers screened using an evidence-based algorithm of physical tests.  Eligible participants were randomised to one of three groups involving either isometric, concentric or eccentric rotator cuff strengthening exercises. They undertook five physiotherapy one-on-one sessions reinforced with a home exercise program. Each group utilised the different mode of rotator cuff strengthening for the first six weeks, followed by six weeks of independent progression, with exercises no-longer group-specific. Key feasibility parameters evaluated included: ease of recruitment, adherence, compliance with the various study components including home exercise program, dropout rates and adverse events. Secondary outcomes included: the Western Ontario Rotator Cuff Index (WORC), the Shoulder Pain and Disability Index (SPADI), an 11-point numerical rating scale (NRS) for pain, shoulder strength using a hand-held dynamometer and, a Global Rating of Change Score (5 point likert scale).

Results: Of 88 interested volunteers, 47 (53%) were screened face-to-face via the algorithm with 30 (26%) of these randomised to the study. Main reasons for exclusion were positive signs of adhesive capsulitis and dominant cervical referral pattern. There were 16 (53%) females. Mean age was 45.8 (SD=14.9) years. Mean duration of symptoms was 16.3 (SD=17.4) months. Adherence to the intervention was 90%, with 3 lost to follow-up. No serious adverse events were reported. Significant between-group differences were not observed. For the entire cohort, pre-post-intervention (Wilcoxon-Sign-Rank) demonstrated a significant difference for all secondary outcomes at 6 and 12-weeks with the mean WORC score improved by 33% (p<0.05) and SPADI by 24% (p<0.05). Significant strength gains across the cohort were also observed at both 6 and 12 weeks. Of the 27 participants, 24 (89%) rated their symptoms “much better” post-intervention on the Global Rating of Change Score.       

Conclusion(s): The results of this study support the feasibility of a full-scale RCT to determine the efficacy of different modes of contraction during rotator cuff exercises when used as part of a semi-standardised program in participants with SPS. Significant improvements in impairment and function were seen in participants undertaking a short exercise-based intervention, regardless of contraction mode.

Implications: A scapular-focussed rotator-cuff strengthening program, utilising principles of progressive tendon loading, is effective in patients presenting with SPS and may be easily integrated into shoulder rehabilitation protocols.  

Funding, acknowledgements: Trial funded by The Arthritis Australia Foundation Zimmer Biomet Grant and the St Vincent’s Hospital Research Endowment Fund

Keywords: Tendinopathy, Subacromial Pain, Rehabilitation

Topic: Musculoskeletal: upper limb

Did this work require ethics approval? Yes
Institution: St Vincent’s Hospital Melbourne
Committee: St Vincent’s Hospital Melbourne HREC
Ethics number: LNR/16/SVHM/169

All authors, affiliations and abstracts have been published as submitted.

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