In the study-group, a device powered by a piezoelectric generator (PIEZOSON 100PLUS, Richard Wolf) was used . At the beginning of each treatment session, the enthesis of the gluteal tendons at the greater trochanter (at the anterior half of its lateral facet) was targeted through a non-inline sonographic focusing, using a linear probe (7.5-12 MHz) connected to an ultrasound scanner (ESAOTE MYLAB FIVE, Genova and Florence, Italy). All patients received 1800 pulses (frequency=4Hz) of an energy flux density of 0.15 mJ/mm2 once a week for three consecutive weeks. At the first treatment session, the energy flux density was gradually increased from 0.05 to 0.15 mJ/mm2 during the first 500 pulses.

In the control-group, we used a mono-frequency device (ROLAND, RT-20 series, frequency=1MHz). We treated an area of 5cm2, softly moving the US-probe around the most painful point of the greater trochanter at the clinical palpation. UST was supplied in a continuous modality, with an intensity of 1.5 W/cm2, for ten consecutive daily sessions of ten minutes each.

Change from baseline p-NRS (pain-on-movement numeric rating scale) at 2 months and at 6 months.

Change from baseline LEFS (Lower extremity functional scale) total score at 2 months and at 6 months