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Effects of Long Duration Low Intensity Ultrasound for Active Trapezius Trigger Points: A Randomized Clinical Trial
Justin H Rigby1, David O Draper2
11 Department of Health & Human Performance, Texas State University , 601 University Drive, San Marcos, TX 78666, USA.
Context:
Upper trapezius trigger points can be debilitating and often lead to chronic pain.
Objective:
To determine if long duration low intensity therapeutic ultrasound is effective at treating upper trapezius trigger point pain compared to an inactive placebo treatment.
Design:
Randomized control trial.
Setting:
Research laboratory.
Patients Or Other Participants:
Fifty-one participants (19 males, 32 females, age = 31.8 ± 12.5 y, ht = 168.6 ± 15.9 cm, mass = 77.1 ± 16.1 kg) diagnosed with chronic upper trapezius pain.
Interventions:
Participants were randomly assigned into an active (n = 32) or sham (n = 19) treatment group. Treatments were applied at least 3 times a week for 4 weeks and each ultrasound treatment lasted 4 h.
Main Outcome Measures:
Participants completed a daily numeric rating scale (NRS) pain diary. Pain pressure threshold was assessed via a pressure algometer. Repeated-measures ANCOVAs were used to examine differences over time and between groups.
Results:
Pain on the NRS was significantly reduced from baseline (5.4 ± 1.7) to the conclusion of the study (4.2 ± 1.6) (F4,254 = 7.747, P < 0.001); however, the reduction did not significantly differ between the two groups (F4,254 = 1.096, P = 0.359). There was an average reduction in pain of 1.1 ± 1.8 points over the course of a 4 h treatment (F4,254 = 18.67, P = 0.001), but this reduction did not differ between groups, (F4,254 = 0.701, P = 0.592). Pain pressure threshold improved by 0.46 ± 1.29 and 0.44 ± 1.73 kg for active and sham groups, respectively, but was not different between groups (F2,142 = 1.168, P = 0.314).
Conclusions:
Four-weeks of low intensity long duration ultrasound reduced upper trapezius trigger point pain, but the improvement is attributed to a placebo effect.
