I have had my piriformis pummelled so much I actually swore really loudly, much to the amusement of the physio staff who could hear me outside the treatment room.
I remember shouting "I want my mum!" as well at one point. 

I have has lots of problems with it from numbness in my foot, sciatica, once its seized so badly I was bent double and couldn't straighten up. All stems from a weak core and hip. I always found that as they treated (proper) sports people, their main priority was to get you back up and running quickly and I never felt (like I had previously with some physios) that they were getting me back to gain more money from me.