Ultrasound-Guided Myofascial Trigger Point Injection Into Brachialis Muscle for Rotator Cuff Disease Patients With Upper Arm Pain: A Pilot Study

OBJECTIVE: To assess the efficacy of trigger point injection into brachialis muscle for rotator cuff disease patients with upper arm pain. METHODS: A prospective, randomized, and single-blinded clinical pilot trial was performed at university rehabilitation hospital. Twenty-one patients clinically diagnosed with rotator cuff disease suspected of having brachialis myofascial pain syndrome (MPS) were randomly allocated into two groups. Effect of ultrasound (US)-guided trigger point injection (n=11) and oral non-steroidal anti-inflammatory drug (NSAID) (n=10) was compared by visual analog scale (VAS). RESULTS: US-guided trigger point injection of brachialis muscle resulted in excellent outcome compared to the oral NSAID group. Mean VAS scores decreased significantly after 2 weeks of treatment compared to the baseline in both groups (7.3 vs. 4.5 in the injection group and 7.4 vs. 5.9 in the oral group). The decrease of the VAS score caused by injection (ДVAS=-2.8) was significantly larger than caused by oral NSAID (ДVAS=-1.5) (p<0.05). CONCLUSION: In patients with rotator cuff disease, US-guided trigger point injection of the brachialis muscle is safe and effective for both diagnosis and treatment when the cause of pain is suspected to be originated from the muscle.