Effect of Blood Flow Restriction Training Versus Pilates on Shoulder Impingement Syndrome

Official title

Blood Flow Restriction Versus Pilates Exercises in Treatment of Patients With Subacromial Impingement Syndrome

Overview

Subacromial impingement syndrome (SAIS) is the most common cause of shoulder pain, accounting for a large proportion of musculoskeletal complaints. It is characterized by narrowing of the subacromial space, leading to pain, weakness, limited range of motion, and impaired shoulder function. Muscle weakness, especially of the rotator cuff and scapular stabilizers, plays a major role in its pathomechanics. Although conventional strengthening exercises are effective, they are often delayed until pain subsides, which may prolong recovery. Blood Flow Restriction (BFR) training and Pilates exercises have recently emerged as promising approaches that may enhance strength and function during earlier, painful stages of rehabilitation. However, limited research has compared both interventions in patients with SAIS. Therefore, this study aims to compare the effectiveness of BFR training versus Pilates exercises, in addition to conventional therapy, on pain, function, range of motion, muscle strength, and proprioception in patients with painful SAIS.

Detailed description

Shoulder pain is one of the most prevalent musculoskeletal complaints, ranking as the third most common condition encountered in primary care settings. Among the various causes of shoulder pain, subacromial impingement syndrome (SAIS) represents the most frequent diagnosis, accounting for nearly half to two-thirds of reported shoulder pain cases. SAIS is characterized by narrowing of the subacromial space, resulting in compression and irritation of soft tissues such as the supraspinatus tendon, long head of biceps tendon, subacromial bursa, and joint capsule.

Clinically, patients with SAIS present with pain during overhead activities, muscle weakness, and a painful arc of motion, particularly between 60° and 120° of shoulder elevation. Weakness of the rotator cuff and scapular stabilizing muscles contributes significantly to altered scapulohumeral rhythm and compromised glenohumeral stability. Consequently, muscle strengthening is considered a cornerstone in rehabilitation programs.

Traditional resistance training typically requires moderate to high loads (around 60% of one-repetition maximum) to achieve strength gains. However, during the painful phases of SAIS, patients may not tolerate heavy loading, leading to delayed initiation of strengthening exercises and prolonged recovery time. Therefore, alternative strengthening strategies that minimize mechanical stress while promoting muscle adaptation are needed.

Blood Flow Restriction (BFR) training is a technique that applies controlled external pressure to partially restrict arterial inflow and venous outflow, enabling strength gains with low-load resistance (approximately 20-30% of 1RM). It stimulates metabolic stress and anabolic pathways, enhancing muscle hypertrophy and strength while reducing joint stress.

Pilates exercises, on the other hand, are mind-body exercises based on principles of control, concentration, centering, precision, breathing, and flow. They emphasize neuromuscular control, core stability, scapular alignment, and coordinated movement patterns. Previous studies have demonstrated beneficial effects of Pilates in improving pain, function, and muscle strength in various musculoskeletal disorders, including shoulder conditions.

Despite the promising effects of both BFR and Pilates, limited evidence directly compares their effectiveness in shoulder rehabilitation, particularly in patients with SAIS. To the author's knowledge, no previous study has directly compared these two interventions in managing painful subacromial impingement syndrome. Therefore, this study aims to evaluate and compare the effects of BFR training and Pilates exercises, in addition to conventional therapy, on pain intensity, functional disability, shoulder range of motion, muscle strength, and proprioception in patients with SAIS.

Interventions

• Other Low load resistance training with BFR
  Participants will perform low-load resistance training combined with Blood Flow Restriction (BFR) 3 times per week for 4 weeks. Each session will last 45 minutes and include exercises for shoulder muscles with cuffs applied to the upper arm to partially restrict blood flow, ensuring safety and gradual load progression.
• Other Pilates exercises
  Participants will perform supervised Pilates exercises 3 times per week for 4 weeks. Each session will last 45 minutes and include mat-based exercises, resistance band work, and equipment-assisted movements targeting shoulder mobility, stability, and posture. Exercises will be progressively adjusted according to participant tolerance and performance.
• Other Cool's shoulder exercises
  : Participants will perform standard Cool's exercises 3 times per week for 4 weeks. Each session will last 45 minutes and focus on targeted shoulder rehabilitation movements designed to improve flexibility, muscle activation, and pain reduction. Exercises will be supervised and progressively adapted based on participant performance

Primary outcome measures

• Shoulder Pain [Time frame: Baseline, week 2, week 4]
• Shoulder Function (SPADI) [Time frame: Baseline, Week 2, Week 4]

Secondary outcome measures (3)

• Range of Motion (ROM) [Time frame: Baseline, Week 2, Week 4]
• Muscle Strength [Time frame: Baseline, Week 2, Week 4]
• Shoulder proprioception [Time frame: Baseline, Week 4]

Eligibility criteria

Inclusion criteria

1 - Age ranging from 18 to 55 years of both genders, with BMI ranging 18.5 to 29.9 Kg/m2 2. Clinically diagnosed with SIS, based on having ≥ 3 positive results of the following; pain during shoulder elevation and overhead activities, the painful arc, Neer impingement, Hawkins-Kennedy impingement, external rotation resistance, or empty can tests 3. Symptoms duration between 4 to 12 weeks (subacute and chronic phases)

4\. pain level should be ranged from 3 to 8 on the VAS .

Exclusion criteria

1 - History of shoulder surgery, traumatic injury or systematic diseases 2. Any cervical problems as cervical disc \& any patient with radioculopathy. 3. Pregnancy. 4. Acute stage of subacromial impingement syndrome 5. Full thickness tear confirmed by the orthopaedist. 6. subjects shouldn't receive any physical therapy sessions in the past 3 months to minimize any confounders to treatment.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Single blind

Primary purpose

Treatment

Study locations

Egypt · 1 center

• Faculty of physical therapy, Rashid university — Rāshid

Identifiers

NCT: NCT07608809 · BFR vs pilates in SAIS

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗