Could there be a connection between extreme flexibility and the inability to land jumps on a consistent basis? I think that Emily's falls are due to her inexperience (MK was not doing a lot of clean performances on her first year on the senior international circuit; Tara had at least one fall per event; etc.), but I think Sasha's problems are physical. If they are connected to her earlier back injuries (Sasha's tendency to fall pre-dates any reports of groin injuries), then Alissa should be OK (in that correcting her technique should help with the jumps), but if it is connected to flexibility, then Alissa might share the problems.