Why do they do that?
I have waited sooooo long for a pain clinic appt for back pain and severe leg pain due to sciatica. I have been fortunate that for whatever reason my pain levels have reduced over the last few weeks, probably because it knew it was going to be knocked into touch at pain clinic and also because it knows I have a neurosurgery appt next week and nothing like walking into those appts looking like nowt is wrong 
anyway, whatever is going on, pain levels are ok (3-4/10).
Saw back specialist (senior clinical physiotherapist) who examined by back and leg, which involved getting me to move in different ways, then podding, poking my spine and muscles around my lumbar area, prodding, poking, and pulling my legs about, getting me to push his hands, reflex tests etc.
And even as he did it I could feel the sciatic pain increasing, as it aggravated it. And now my back is really sore and my feet are numb and tingling and my sciatic pain is shooting through my hips and butt.
I know he didn't mean it. But, I really didn't think the pain clinic would make it WORSE!
And he didn't DO anything to help with the pain levels/pain management today.