Jo and Sarah -- there could be a few reasons for why it's difficult to sit up straight and/or why someone may have difficulties. One could be weakness in the core musculature of the body (spine and abdominals) -- all of which will get stronger in time. Another could be weak/tight hips (same, will get stronger in time), a person could have joint structure that limits the ease. My overall feeling, however, is that in time and with practice, a person will gain the strength needed!!! Pilates is a practice!
Thank you for addressing this very common problem. Yoga block is another great prop to assist here. My go to reason for this issue is tight Jammie's. Yes? I notice that bent legs usually gets that back tall. Thank you Amy & thank you PA
C-C-L ...yes a wedge would work too. We wanted to keep this tutorial short in length so I didn't go in as much depth as I could have . There are many options for assisting this issue, a wedge is certainly an option too.