High-power pain threshold ultrasound technique in the treatment of active myofascial trigger points:: A randomized, double-blind, case-control study

Objective: To study what effects a high-power, pain-threshold, static ultrasound technique applied to acute myofascial trigger points of the upper trapezius has on pain and on active cervical lateral bending. Design: Double-blind randomized trial. Setting: Physical therapy unit of a private general hospital. Participants: Seventy-two adults with acute pain on I side of the neck, admitted to the outpatient unit during 1999 and 2000. Interventions: Not applicable. Main Outcome Measures: Visual analog scale and gonio-metric measurement of active lateral bending of the neck performed daily after treatment sessions and length of treatment (number of therapy sessions). Results: High-power ultrasound applied to the trigger points before stretching the muscle was more effective (P<.05) than conventional ultrasound, and it also significantly (P<.001) decreased the length of therapy. Conclusions: High-power, pain-threshold, static ultrasound technique may be considered in the treatment of patients with acute myofascial pain syndrome, with the understanding that this technique demands more concentration and communication between the patient and the therapist.