On middle split pulls, I can only do 2-4 reps before my quads cramp like crazy. The way the video demonstrates the stretch, it seems to imply that my hips will be angled at 90 degrees and then I pull my legs off the wall before doing middle split pulls. One small problem, I can't even sit at a 90 degree with straight legs without massive assistance (like a wall) and easing into it. So to ask me to pull my legs off the wall and then pull them apart leads to massive cramping?
What's the best way to modify this? (modifications are not well explained for almost any stretch - took me weeks and months to figure these out for myself)