Sustained acoustic medicine: wearable, long duration ultrasonic therapy for the treatment of tendinopathy

Objectives: The effectiveness of sustained acoustic medicine to alleviate pain and improve function in subjects with elbow or Achilles tendinopathy was evaluated through a level IV case series study. Subjects were trained to self-apply the wearable, long-duration, low-intensity ultrasonic device on their affected body part at home for 4hours a day, at least 5 times per week over 6 weeks. Twenty-five subjects with clinician-diagnosed tendinopathy of the elbow (medial or lateral epicondyle) or Achilles tendon were enrolled. Methods: Pain measurements were recorded before, during, and after daily intervention using an 11-point numeric rating scale (NRS). Function of the injured limb was assessed biweekly using dynamometry. Repeated measures ANOVAs and paired-samples t-tests were used to examine the effect of treatment over time. Results: Among subjects with elbow tendinopathy (n=20), a 3.94 +/- 2.15 point reduction in pain (p=0.002) was observed over the 6-week study and a 2.83 +/- 5.52kg improvement in grip strength (p=0.04) was observed over the first two weeks. In addition, a significant reduction in pain was observed within the 4-h treatment sessions (p<0.001). Among 5 subjects with Achilles tendinopathy, a reduction in pain and improvement in strength was also observed. Conclusions: Daily multi-hour ultrasonic therapy was associated with improved pain and increased function in subjects with chronic tendon injuries. This trial showed the safety and feasibility of self-administration of sustained acoustic medicine, and suggests that this therapy may be clinically beneficial in the treatment of tendinopathies of the elbow and Achilles tendon. A randomized controlled trial appears warranted to more definitively investigate the therapeutic potential of this treatment modality.