Greater trochanteric pain syndrome (GTPS) is characterized by pain over the greater trochanter, which can refer down the lateral aspect of the hip. Historically, conservative treatments such as rest/activity modification, anti-inflammatory medication, physiotherapy and local corticosteroid injection, are employed as first-line management, with some refractory cases requiring surgical intervention.

Acknowledging the unpredictable response and frequent recurrences associated with traditional non operative treatment, the risks and prolonged rehabilitation associated with surgery, and the favorable results from prior studies involving radial pressure waves as a treatment for GTPS, the aim of this study is to investigate the dose-related effect of focalized shockwave treatment at different total energy influx in patients with chronic GTPS.

Shockwave therapy (SWT) has been used successfully since the late 1980s for the management of various musculoskeletal disorders including plantar fasciopathy, achilles tendinopathy, shoulder calcific tendinopathy, and lateral epicondylitis. Although there are some negative trials, there are now many randomized, double-blinded, clinical trials that support the use of SWT for the above conditions. Acknowledging the unpredictable response and frequent recurrences associated with traditional non operative treatment, the risks and prolonged rehabilitation associated with surgery, the recognition of gluteal tendinopathy as a potential source of pain, and the favorable results from prior studies involving radial pressure waves as a treatment for GTPS, the aim of this study is to investigate the dose-related effect of shockwave treatment at different total energy by adjusting the energy flux density (EFD) in patients with chronic GTPS. The shockwave has been widely recognized in literature as a biological regulator, currently the biological effects of shockwaves can be obtained using lower energy than in the past.

While the intensity or delivered energy is considered by some researchers to be a key factor for successful treatment, in current literature reviews, debate continues over the appropriate energy intensity and the total delivered energy that should be applied to the tissue.

Therefore, higher intensity treatments usually require local anesthesia, which is known to reduce the efficacy of the treatment. Furthermore, some animal tests reported that an influx of energy of over 0.60 mJ/mm2 can cause permanent damage on the tendon. On the other hand, low-intensity energy is safer but has the disadvantage of lower treatment effects.

The investigators hypothesize that a very low intensity protocol of ESWT has different effects on pain and function than a conventional protocol in a patient with GTPS syndrome.

Inclusion Criteria:

1. Patients of either sex, aged oved 18 years, complaining of pain located anterior, lateral or posterior to the great trochanter for more than 3 months.
2. Pain while lying on the affected side.
3. Local tenderness on palpation of the area of the great trochanter of patients with this symptom as the reason for the consultation.

Exclusion Criteria:

1. Presence of signs and symptoms of another cause of regional hip pain.
2. Presence of hip internal rotation 20° and extension deficit or other range of motion limitation 10º
3. Previous hip surgery or use of ESWT for GTPS.
4. Acute low back pain
5. Vascular, neurologic, rheumatic diseases.
6. Tumor in the area or local infection to the hip joint region.
7. Pregnancy.
8. Severe coagulation disorders.

The participants will be blinded to the type of ESWT treatment and the assessor, data managers, statistician and study monitors will be blinded to the allocation. All participants who receive ESWT treatment will be treated using the same device (Duolith SD1, STORZ Medical, Switzerland) regardless of what group they are included in. The participants will not be able to predict the allocated group based on the appearance of the ESWT treatment. The blinding will be maintained until the data are locked. For blinding evaluation, allocation guessing will be assessed immediately after the final treatment. Practitioners and assessors will be instructed to treat the participants according to predefined standard operating procedures during the trial to maintain blinding.