On the plus side it does pass, but man I know how frustrating it is.
I have used various opions as offered above, but sometimes I just have to sit on the floor and put my ankles on his shoulders and hold him between my legs, or otherwise hold his shoulders down (gently) with my knees and change him upside down. I'm pretty good at lightening speed now but he's my second wriggler....and my hands are nice and strong after years of wrangling with crooks in handcuffs ()