Effects of Low-Load Exercise on Postneedling-Induced Pain After Dry Needling of Active Trigger Point in Individuals With Subacromial Pain Syndrome

Abstract

Background: The application of dry needling usually is associated with postneedling-induced pain. A postneedling intervention to reduce this adverse event is needed.

Objective: To determine the effectiveness of low-load exercise on reducing postneedling-induced pain after dry needling of active trigger points (TrPs) in the infraspinatus muscle in subacromial pain syndrome.

Design: A 72-hour follow-up, single-blind randomized controlled trial.

Setting: Urban hospitals.

Participants: Individuals with subacromial pain syndrome (n = 90, 52% female, mean age: 35 ± 13 years) with active TrPs in the infraspinatus muscle.

Interventions: All individuals received dry needling into the infraspinatus active TrP. Then, they were divided randomly into an experimental group, which received a single bout of low-load exercise of shoulder muscles; a placebo group, which received inactive ultrasound for 10 minutes; and a control group, which did not receive any intervention.

Outcome measures: Numerical Pain Rating Scale (0-10 point) was administered postneedling, immediately postintervention (2 minutes), and 24, 48, and 72 hours after needling. Shoulder pain (Numerical Pain Rating Scale, 0-10) and disability (Disabilities of the Arm, Shoulder and Hand; Shoulder Pain and Disability Index) were assessed before and 72 hour after needling.

Results: The 5 × 3 analysis of covariance showed that the exercise group demonstrated a larger decrease in postneedling-induced pain immediately after (P = .001), 24 hours (P = .001), and 48 hours after (P = .006) than placebo or control groups. No differences were found at 72 hours (P = .03). Similar improvements in shoulder pain (P < .001) and related disability (Disabilities of the Arm, Shoulder and Hand: P < .001; Shoulder Pain and Disability Index: P < .001) were observed 72 hours after needling, irrespective of the treatment group.

Conclusions: Low-load exercise was effective for reducing postneedling-induced pain on active TrPs in the infraspinatus muscle 24 and 48 hours after needling. The application of a postneedling intervention did not influence short-term pain and disability changes.

Level of evidence: I.