Therapeutic Ultrasound
Limited evidence supports that therapeutic ultrasound might be effective compared to placebo.

One high quality study (Ebenbichler 1998) evaluated the use of ultrasound in treating carpal tunnel syndrome.  In a randomized controlled trial, Ebenbichler 1998 evaluated the efficacy of ultrasound (20 sessions of 15 minute interventions of 1MHz, 1.0 W/cm, pulse mode 1:4 at 5 sessions/week for 2 weeks followed by 2 sessions/week) versus placebo ultrasound on the treatment of carpal tunnel syndrome.  Multiple measures showed significant improvement in the ultrasound group: grip strength, motor distal latency (p<0.001), and pinch strength.