Comparison of high-power pain threshold ultrasound therapy with local injection in the treatment of active myofascial trigger points of the upper trapezius muscle.

OBJECTIVE: To compare the effects of high-power pain threshold ultrasound (HPPTUS) therapy and local anesthetic injection on pain and active cervical lateral bending in patients with active myofascial trigger points (MTrPs) of the upper trapezius muscle.

DESIGN: Randomized single-blinded controlled trial.

SETTING: Physical medicine and rehabilitation department of university hospital.

PARTICIPANTS: Subjects (N=49) who had active MTrPs of the upper trapezius muscle.

INTERVENTIONS: HPPTUS or trigger point injection (TrP).

MAIN OUTCOME MEASURES: Visual analog scale, range of motion (ROM) of the cervical spine, and total length of treatments.

RESULTS: All patients in both groups improved significantly in terms of pain and ROM, but there was no statistically significant difference between groups. Mean numbers of therapy sessions were 1 and 1.5 in the local injection and HPPTUS groups, respectively.

CONCLUSIONS: We failed to show differences between the HPPTUS technique and TrP injection in the treatment of active MTrPs of the upper trapezius muscle. The HPPTUS technique can be used as an effective alternative to TrP injection in the treatment of myofascial pain syndrome.