Comprehensive supervised heavy training program versus home training regimen in patients with subacromial impingement syndrome: a randomized trial

Key Points

1. Supervised high intensity exercise training is not superior to low intensity home exercise training for managing subacromial shoulder pain (SSP) in this sample of participants.
2. Both exercise types appear to improve baseline pain and function in this cohort of people with SSP.
3. The optimal structure of an exercise program for managing SSP continues to be unknown.

BACKGROUND & OBJECTIVE

Exercise therapy is the recommended first-line intervention to manage subacromial shoulder pain (SSP) (I refuse to use the term impingement) (1). Exercise therapy is an umbrella term that can include anything from stretching to strengthening to motor control exercise and is the most popular treatment provided by physiotherapists for managing SSP (2). Despite the popularity of exercise amongst physiotherapists and the broad recommendation to prescribe it by clinical practice guidelines, the exact structure of the ‘optimal’ exercise program for SSP is unclear.

This randomized controlled trial aimed to compare a supervised heavy resistance (HR) training program (group 1) with a home-based lower intensity training program (group 2). The authors hypothesized that the HR training program would be superior.

Exercise therapy is the recommended first-line intervention to manage subacromial shoulder pain.

Many exercise options are on the table for helping someone with shoulder pain, because most exercise programs will improve some dimension of that person’s pain experience.

METHODS

This was a randomized controlled trial. The inclusion criteria were:

• Subacromial shoulder pain of any intensity and duration
• 3 positive tests out of 5 from Neer’s test, Hawkins Kennedy test, painful arc, Jobe test and resisted external rotation

Both groups completed a 12-week exercise regimen. Both exercise programs consisted of exercises including stretches, mobility exercises, strengthening exercises and postural exercises.

The supervised HR training program (group 1) consisted of:

• Range of motion exercises
• Strengthening exercises, including side lying ER, IR, scaption, push up plus, serratus supine punch, low row, high row
• Stretching exercises, including pectoralis minor, posterior and inferior capsule

The home training program (group 2) consisted of:

• 1 range of motion exercise
• 3 strengthening exercises: external rotation in neutral and 90 degrees and serratus anterior strengthening
• Pec stretch and posterior shoulder stretch

See the video for a demonstration of the two exercise programs.

EXERCISE PROGRAMS PERFORMED

A key difference between the programs was the intensity of the exercise. Group 1 progressed exercise according to maximal repetitions (RM). In the final 3 weeks of the exercise program, group 1 reached an intensity of 6RM. Group 2 still progressed repetitions and resistance of the exercises, but this was at a lower intensity and not based on an objective measure.

Primary outcomes measured were the Constant-Murley Score (CS) and Shoulder Rating Score (SRQ) and these were measured at baseline and at 9 months.

RESULTS

• 126 participants (63 in each group) were included in the study, 65 male and 61 female and the average age was 61.

• Both groups displayed significant and clinically meaningful improvements from baseline to 3 and 6 month follow up. The key question is, was there a significant between group difference? The answer is no. Both groups improved similarly.

• Compliance was similar between groups, as was the dropout rate, which was substantial for both groups.

LIMITATIONS

• This is a decent study: a good sample size of 126, decent methods, and a real-world applicable inclusion criteria.

• The dropout rate warrants discussion: 27 participants dropped out of the HR training program and 21 participants dropped out of the low intensity home program. Whilst this seems bad at first glance, the authors deserve credit for using an intention to treat analysis, which is a way of minimizing any bias that may have arisen due to this dropout rate.

• Most participants expressed a preference to enter the low intensity training group, and this might have affected the results of the HR training group.

• Possibly, we could have gleaned more information about the research question if the exercises were limited to resistance exercise only. The addition of stretches, postural exercise and mobility exercises only adds more complexity to interpreting the findings.

• The average age was 61 and perhaps a 61-year-old person with SSP might respond differently to a HR training program compared to a 30-year-old, so please remember this.

CLINICAL IMPLICATIONS

Okay, so what does all this mean? In short, a supervised HR training program based on RM is not superior to a standardised home training program for SSP in this cohort. However, both programs were associated with clinical and statistically significant improvements from baseline. This result is reminiscent of a Lancet study published in 2021 which nearly broke the internet (3).

Again, we’re seeing a challenge to the assumption that high intensity/volume exercise programs are superior to low intensity/volume programs. This simply does not appear to be the case when rehabilitating common musculoskeletal pathologies across various bodily regions (4,5).

For me, this comes back to mechanisms of exercise; how is exercise effective for improving shoulder pain and function? We often see the possible mechanisms of exercise for shoulder pain have little to do with mechanical variables (such as strength and posture) (6) and more to do with psychosocial factors, contextual and non-specific effects.

This means that many exercise options are on the table for helping someone with shoulder pain, because most exercise programs will improve some dimension of that person’s pain experience, but you just might not be able to see it and measure it with your dynamometer!

+STUDY REFERENCE

Schydlowsky P, Szkudlarek M, & Madsen O (2022) Comprehensive supervised heavy training program versus home training regimen in patients with subacromial impingement syndrome: a randomized trial. BMC Musculoskelet Disord, 23(1), 52.

SUPPORTING REFERENCE

1. Pieters, L., et al., An Update of Systematic Reviews Examining the Effectiveness of Conservative Physical Therapy Interventions for Subacromial Shoulder Pain. J Orthop Sports Phys Ther, 2020. 50(3): p. 131-141.
2. Smythe, A., et al., Physiotherapists deliver management broadly consistent with recommended practice in rotator cuff tendinopathy: An observational study. Musculoskelet Sci Pract, 2020. 47: p. 102132.
3. Hopewell, S., et al., Progressive exercise compared with best practice advice, with or without corticosteroid injection, for the treatment of patients with rotator cuff disorders (GRASP): a multicentre, pragmatic, 2 × 2 factorial, randomised controlled trial. The Lancet, 2021. 398(10298): p. 416-428.
4. Messier, S.P., et al., Effect of High-Intensity Strength Training on Knee Pain and Knee Joint Compressive Forces Among Adults With Knee Osteoarthritis: The START Randomized Clinical Trial. JAMA, 2021. 325(7): p. 646-657.
5. Ganderton, C., et al., Gluteal Loading Versus Sham Exercises to Improve Pain and Dysfunction in Postmenopausal Women with Greater Trochanteric Pain Syndrome: A Randomized Controlled Trial. J Womens Health (Larchmt), 2018. 27(6): p. 815-829.
6. Powell, J.K. and J.S. Lewis, Rotator Cuff-Related Shoulder Pain: Is It Time to Reframe the Advice, "You Need to Strengthen Your Shoulder"? J Orthop Sports Phys Ther, 2021. 51(4): p. 156-158.