Despite the widespread use of therapeutic ultrasound as one of the most popular and commonly used modalities in the field of physiotherapy for LBP patients, there is still limited evidence of its effectiveness. Only a few RCTs have investigated the effect of ultrasound in treating patients with chronic LBP; often with varying methodology qualities and very small sample sizes, and have not been able to provide evidence regarding its usefulness.
The RCT we have described will evaluate the effectiveness of therapeutic ultrasound in addition to exercise therapy in patients with chronic LBP. The advantages of this study would be comparing the ultrasound with pla- cebo ultrasound, which would clarify the value of adding ultrasound to a semisupervised exercise program. Limited possibilities for double blinding can be a potential limitation to this study. Meanwhile we will evaluate potential bias by asking the patients whether they think they received real or sham ultrasound on the last treat- ment session. Recruiting a sufficient number of patients will be one of the most challenging elements of this study since it will be conducted without substantial funding.