Comparison of Upper Trapezius and Infraspinatus Myofascial Trigger Point Therapy by Dry Needling in Overhead Athletes With Unilateral Shoulder Impingement Syndrome

Context: Chronic musculoskeletal disorders in the shoulder joint are often associated with myofascial trigger points (MTrPs), particularly in the upper trapezius (UT) muscle. Dry needling (DN) is a treatment of choice for myofascial pain syndrome. However, local lesions and severe postneedle soreness sometimes hamper the direct application of DN in the UT. Therefore, finding an alternative point of treatment seems useful in this regard. Objective: To compare the efficacy of UT versus infraspinatus (ISP) DN on pain and disability of subjects with shoulder pain. The authors hypothesized that ISP DN could be as effective as the direct application of DN in UT MTrP. Design: Single-blind randomized clinical trial. Setting: Sports medicine physical therapy clinic. Participants: A total of 40 overhead athletes (age = 36 [16] y; 20 females and 20 males) with unilateral shoulder impingement syndrome were randomly assigned to the UT DN (n = 21) and ISP DN (n = 19) groups. Intervention: An acupuncture needle was directly inserted into the trigger point of UT muscle in the UT DN group and of ISP muscle in the ISP DN group. DN was applied in 3 sessions (2-day interval between each sessions) for each group. Main Outcome Measures: Pain intensity (visual analog scale), pain pressure threshold, and disability in the arm, shoulder, and hand were assessed before and after the interventions. Results: Pain and disability decreased significantly in both groups (P < .001) and pain pressure threshold increased significantly only in the ISP group (P = .02). However, none of the outcome measures showed a significant intergroup difference after treatments (P > .05). Conclusions: Application of DN for active MTrPs in the ISP can be as effective as direct DN of active MTrPs in the UT in improving pain and disability in athletes with shoulder pain, and may be preferred due to greater patient comfort in comparison with direct UT needling.