Effects of Nunchaku Exercise for Improving Frozen Shoulder

Adhesive capsulitis, or frozen shoulder, is a progressive fibro-inflammatory condition characterized by synovitis, capsular thickening, and collagen remodeling, leading to substantial restrictions in active and passive shoulder motion. These movement limitations commonly result in impaired sleep, difficulties in self-care, and reduced capacity for work and leisure activities. Although conservative rehabilitation is the standard of care, real-world effectiveness is frequently constrained by poor adherence to home-based exercises, often due to discomfort and exercise monotony.

This randomized controlled trial investigates the effects of nunchaku exercise as a novel rehabilitative modality for individuals with adhesive capsulitis in the thawing phase. Nunchaku practice requires rhythmic, multiplanar arm motions, coordinated scapulohumeral control, and dynamic stabilization. These biomechanical characteristics align with therapeutic goals of end-range stretching, neuromuscular retraining, and rotator-cuff-based stabilization. The inherently rhythmic, skill-acquisition nature of nunchaku practice may also enhance intrinsic motivation and adherence relative to traditional exercise programs.

In this assessor-blinded, two-arm, parallel-group trial, 50 ethnic Chinese adults aged 45 years or older will be recruited and randomized 1:1 to either a standard shoulder mobilization and stretching exercise program (SMSE) or a nunchaku exercise program (NE). The nunchaku exercise program will adapt into a safe, soft-towel form suitable for older adults. Both interventions last 12 weeks and consist of twice-weekly, 60-minute, small-group sessions, supplemented by encouraged home practice. SMSE includes joint mobilization, end-range stretching, strengthening. NE follows the Level 1 nunchaku syllabus of the nunchaku system from the Hong Kong nunchaku association.

Outcomes will be assessed at baseline, week 6, week 12, and week 24. The primary outcome is the Shoulder Pain and Disability Index (SPADI). Secondary outcomes include the Visual Analog Scale for pain, Constant-Murley Score, pain-free range of motion, and intervention enjoyment (PACES-8). Adherence will be monitored through attendance, dropout rates, and weekly self-practice time.

This study aims to determine whether nunchaku exercise can improve adherence and produce superior clinical outcomes compared with standard rehabilitation in middle-aged and older adults with adhesive capsulitis.

Inclusion criteria

• Ethnic Chinese;
• Age 45 years or above;
• Diagnosed with Adhesive Capsulitis (Frozen Shoulder) and currently in the thawing stage.

Exclusion criteria

• Presence of secondary causes of shoulder stiffness, including recent trauma, post-surgical stiffness, or structural lesions such as full-thickness rotator cuff tears or severe glenohumeral arthritis;
• Receipt of recent shoulder treatments known to influence short-term outcomes, including corticosteroid injections within the past three months, hydrodilatation, manipulation under anesthesia, arthroscopic capsular release within the past six months, or structured shoulder physiotherapy within the past three months;
• Presence of somatic conditions that limit their ability to participate safely in exercise (e.g., inability to walk without an assistive device).