Aye Michael,
I have to admit I don’t know what a piriformis is.
It's the deep muscle beneath your buttock muscles that controls the rotation of the pelvis and the sciatic nerve runs through it. So, when the piriformis spasms, it grips your sciatic nerve!
Trying to kickstart the bikes, or bend, to do maintanence is a
NO! As the muscle spasms, as it does after sitting down, turning over in bed etc.
It's a pain in the arse!
Good health, Bill