For a few weeks now, if I’ve been sitting with bent legs (I.e. curled up on sofa or sitting on heels, or crossed legs etc), when I get up, the backs of my legs (behind knees) basically cannot support my weight for a few moments/steps (I hobble as cant take real steps) but then I can sort of walk it off.
I haven’t injured my legs, doesn’t feel skeletal or muscular, so was wondering if it could be ligaments or tendons or whatever?