Immediate effect of myofascial trigger points therapy in patients with unilateral shoulder impingement syndrome

INTERVENTION: 1. The trigger point therapy group will receive one session of myofascial trigger point therapy by an experienced physiotherapist. Treatment process will be repeated 3 times on each active/latent trigger point in seven following muscles: upper trapezius, levator scapulae, rhomboids, pectoralis minors, supraspinatus, infraspinatus, teres minors. Pressure on each trigger point will be maintained for 30‐60 seconds (<1 minute), The whole treatment lasts between 20 and 30 minutes. These procedures are performed only once. 2. The ultrasonographic (US)‐guided subacromial injection group will receive corticosteroid injection into the subacromial bursa (Triamcinolone 1 ml of 10mg/1mL with 1% lidocaine is injected) by a physiatrist. This injection is performed only once. 3. The combined treatment group will receive myofascial trigger point therapy and corticosteroid injection (Triamcinolone 1 ml of 10mg/1mL with 1% lidocaine) into the subacromial bursa. The injection administered immediately before myofascial trigger point therapy. These procedures/injection are performed only once. 4. Since only one treatment is administered, fidelity issue is not applicable. CONDITION: Patients with unilateral shoulder impingement syndrome PRIMARY OUTCOME: Pain intensity assessed by numeric rating scale (NRS). ; ; Pressure pain threshold assessed by digital algometer ; ; Shoulder motor control ability by kinetic shoulder motor control test ; ; ; ; SECONDARY OUTCOME: Disabilities of Arm, Shoulder and Hand (DASH) questionnaire ; Functional activity assessed by patient specific‐functional scale (PSFS) ; ; Global rating of change scale ; Shoulder range of motion assessed by goniometer and inclinometer ; INCLUSION CRITERIA: 1. Aged 20‐65 patients with chronic unilateral nontraumatic shoulder pain 2. Meet at least 1 following 3 clinical diagnostic test: Neer tests (pain during passive abduction) / Hawkins test / painful arc sign 3. Numerical pain rating scale (NRS): >3/10 points during shoulder movement 4. Diagnosis of SIS by physiatrists