Hi Delta,
there are some movements that one simply can not do after fusion. I am fused T8-sacrum, and I can not bend in the middle at all. I can of course still bend from the hips, and can bend a little in my upper back, but if I try to bend in my actual middle I simply can't. I doesn't hurt, you just can't move that way. Same thing for twisting. If you try to do it you just can't. I don't think there is much risk of hurting your spine/fusion once fusion is complete by trying these things, but you will just be unable to. Surprisingly I have gained back a fair amount of flexibility 2 years after surgery. By this I mean I can now bend against my fusion and manage to clip my toenails, something which seemed and was impossible in the first year after surgery. You should check out TiEd's signature which has photos of his ability to bend and twist after a full spine fusion. Amazing how the body can accommodate such a major surgical alteration to the spine!
Best of luck,
Gayle, age 50
Oct 2010 fusion T8-sacrum w/ pelvic fixation
Feb 2012 lumbar revision for broken rods @ L2-3-4
Sept 2015 major lumbar A/P revision for broken rods @ L5-S1
mom of Leah, 15 y/o, Diagnosed '08 with 26* T JIS (age 6)
2010 VBS Dr Luhmann Shriners St Louis
2017 curves stable/skeletely mature
also mom of Torrey, 12 y/o son, 16* T, stable