I have this same condition which started some 8 weeks ago now. Firstly misdiagnosed as a urinary infection but upon proper testing was pronounced as SPD.
At its worst I could stand or walk for no more that 10-20 minutes. Doing the weekly shop would render me useless for days.
I was however refered to a "back clinic" at my local hospital and of the 8 women there only three of us had SPD problems in varying degrees. Unfortunatly this clinic, run by the physiotherapy department was none too helpful. I was told in no uncertain terms that the only remedy was to remain as imobile as possible.
"dont do anything that agravates it dear"
so thats standing, walking, sitting and lying in bed then? sign me up for a floatation tank for the next 15 weeks maybe?
Fortunatly the very next day I managed to get a cancelation for a one to one session with an actual phisotherapist at another hospital.
This was a revelation. Firstly she actually examined me and with the help of some manipulation from her and some exersizes to be done at home, I am in a stable state now. Yes I have to be very careful about how I move but at least I can move without feeling like I am being ripped in two.
So my advise would be if you do get fobbed off with crutches and a corset and are told to sit still for three months like I was. Then make yourself a nuisance and get a one to one session. I am not saying it will work for everyone but I am now back at work and able to live a realtivly normal life. As opposed to sitting or lying in pain for months.
Also as a final note you have to make sure that your midwives understand the implications of this condition during labour. A close friend of mine has recently had to undergo 10 weeks of intensive physio after the birth of her daughter because she was positioned in stirrups during labour despite having explained about the SPD problems that she had.
So keep those legs together ladies!
Good luck everyone