<b>Effectiveness of Low-Level Laser Therapy Versus Ischemic Compression on Pressure Pain Threshold Using Algometry in Upper Trapezius Myofascial Pain Syndrome: A Randomized Controlled Trial</b>

Background: Upper-trapezius myofascial pain syndrome is characterized by trigger-point tenderness and reduced pressure pain threshold. Low-level laser therapy and ischemic compression are commonly used interventions, but their comparative effects remain uncertain. Objective: To compare the effects of low-level laser therapy and ischemic compression on pressure pain threshold in individuals with upper-trapezius myofascial pain syndrome. Methods: This randomized controlled trial included 40 adults allocated equally to low-level laser therapy or ischemic compression. Both interventions were administered three times weekly for four weeks. Pressure pain threshold was measured using a pressure algometer at baseline and after treatment. Within-group changes were assessed using paired-samples t tests, and changes between groups were compared using an independent-samples t test. Results: Pressure pain threshold increased from 2.15 ± 0.42 to 3.85 ± 0.55 kg/cm² in the low-level laser therapy group and from 2.20 ± 0.45 to 3.40 ± 0.60 kg/cm² in the ischemic-compression group. Mean improvements were 1.70 ± 0.48 and 1.20 ± 0.52 kg/cm², respectively. The between-group difference was 0.50 kg/cm² (95% CI: 0.18–0.82; p=0.003; Hedges’ g=0.98). Conclusion: Both interventions improved pressure pain threshold, but low-level laser therapy produced a greater short-term increase in mechanical pain tolerance. Keywords: Algometry; Ischemic compression; Low-level laser therapy