Assessment of Effectiveness of Dry Needling for Treating Shoulder Pain
Condition: Chronic Shoulder Pain
MeSH terms: Shoulder Pain
Study type: Interventional

Summary: 
      The aim of the study is to evaluate the effects of active dry needling (aDN) in the treatment
      of myofascial trigger points of the infraspinatus muscle (MTP). For this purpose, this
      technique was compared to placebo dry needling (pDN) for short-term pain relief and increased
      glenohumeral internal rotation range. The second objective is to explore whether improvements
      in perceived pain and functional capacity correlate with changes in electromyographic
      activity.
    

Detailed description: 
      This study is a randomized, double-blind, placebo-controlled clinical trial comprising a
      sample of 30 volunteers with unilateral shoulder pain of both sexes, aged 18 to 35 years.
      They were clinically evaluated to assess inclusion and exclusion criteria. For inclusion in
      the study, volunteers had unilateral shoulder pain for more than 3 months and were
      symptomatic at the time of evaluation. The volunteers were randomized into two groups (G1:
      active dry needling) versus (G2: placebo dry needling). The procedure was performed by one
      investigator, while outcome measures (pressure pain thresholds, VAS, glenohumeral internal
      rotation deficit, and muscle activity) were assessed by other investigators, ensuring a
      double-blinded evaluation of the experiment. Volunteers were recruited through social
      networks and emails. The study was conducted in two experimental sessions on separate days,
      at least 48-72 hours apart to avoid carry-over effects. Primary and secondary outcomes were
      assessed at baseline, immediately after and 48-72 hours after dry needling.

      Assessment of infraspinatus and middle deltoid muscle activity was performed by
      electromyography (EMG). For the EMG protocol, the patient remained standing while holding a
      distal load, the magnitude of which depended on the patient's weight. In patients weighting
      less than 68 kg, a load of 1.5 kg was used; those weighting more than 68 kg lifted 2.5 kg.
      After a brief familiarization period, patients were asked to perform 5 repetitions of
      shoulder elevation in a scapular plane with external rotation and elbow extended, ranging
      from 30° to 90°. EMG recordings were taken during the ascent and descent, with a duration of
      3 seconds at each stage. The movement was synchronized using a metronome so that there was as
      little variability as possible between participants.

      The study is original and there are no previously published data available. Thus, data
      obtained from the pilot study were used for sample size calculation. The variable with the
      lowest coefficient of determination (R-squared) was considered as a primary outcome (pain
      perceived by visual analog scale), and applied as input for the calculation. The analysis was
      performed with an effect size of 0.76, an alpha of 5% and a power of 95%. The results
      indicated that a total of 22 volunteers were needed. Assuming a loss of 20%, each group
      consists of 14 volunteers (with a total sample of 28 volunteers). The sample calculation was
      performed using the G-Power 3.1.9.7 software.

      The study was pre registered in the brazilian database (www.ensaiosclinicos.gov.br) before
      starting data collection, although identifier were not provided.
    

Intervention name(s): Active Dry Needling; Sham Dry needling
Intervention type(s): Other; Other
Intervention description(s): All participants in this group received an ADN session with an intramuscular insertion of a 25 mm X 0.22 mm acupuncture needle into the infraspinatus muscle. The dry needling was performed with the rapid entry and exit technique.; All participants in this group received one session of SDN with a 25 mm X 0.22 mm acupuncture needle over the infraspinatus region. To ensure that the blunt needles did not puncture the skin during the experimental session (and for patient comfort), each needle was individually cut and polished and checked for sharpness against the investigator's fingertip. As a precaution against infection, each patient was treated with a separate dummy needle.
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Active Dry Needling Sham Dry Needling
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Treatment