Straddle Up & Jefferson Curl

Hello, I have moved on to the straddle up and Jefferson curl portion of core. I do not have a very good straddle but have no problem with the up part. Any suggestions?

Also, I have ben doing the Jefferson curls without weight. Is that recommended when starting out? With straight legs and no weight I barely touch the floor. 

Thanks!

Begin with a minimum of 1-2kg which is the minimum for a decent benefit on the spine.

Ideally with IM you should have a minimum of groin mobility, can you post a video of iM1? have you ever considered to get the middle split series?

Thanks Alessandro. I will add a dumbell the next time I do the Jefferson curls.

I need to get better about posting videos. I have not done that yet. I am, however, the proud owner of all three stretch series and they humble me every time I do them.