Welcome to TE.
Oakleaf makes an important point. Is the problem that you can't swing your leg over the back wheel and saddle so you want to try to step through? There are some tricks to get around this (to a certain degree) if that's the case.
Once you are straddling the bike are there any issues with flexing the hips while pedaling? If there are, it will effect how upright you will need to be on the bike.
Havign said that, the foldable bikes like the Bike Friday and Dahon mentioned above are good work arounds.
Living life like there's no tomorrow.
http://gorgebikefitter.com/
2007 Look Dura Ace
2010 Custom Tonic cross with discs, SRAM
2012 Moots YBB 2 x 10 Shimano XTR
2014 Soma B-Side SS