The article of Peng and Tumber nicely reviewed current knowledge about ultrasound-guided interventional procedures for patients with piriformis syndrome, border nerve syndrome, and pudendal neuralgia. In the case of pudendal neuralgia, they stated that pudendal nerve entrapment syndrome might be caused either by the pudendal nerve entrapment between the sacrotuberous and the sacrospinous ligament or inside the Alcock s canal.