I've been working through HLL progression with surprising difficulty.
In general once I start to lift my legs above horizontal there is a huge amount of pressure on my shoulder joint and I just can't get all the way up.
Today experimenting with the Undergrip Grip HLL, which is the final HLL in the sequence, I found I could completely relax my shoulders, sinking a few inches lower, and to my surprise and joy, the feet easily went to the bar.
My best guess is undergrip totally disengages the lats and on the normal grip my lats are fighting my abs keeping me from lifting.
Any advice on how to improve the normal grip would be appreciated, or is it best just to be happy with the Undergrip HLL?
FWIW the same holds for Circular HLL.