And what is the difference between the static hold and “pulling” yourself from dead hang to lever to inverted hang, all while keeping a straight body? I know it’s good for the abs, back, rear delts. Is it good for the arms? (IT IS straight arm work, isn’t it? 
)
Thanks, Vlad
(right now I do the advanced tuck for 10 seconds every 2 hours, and think of advancing by about 5 seconds per week. When I can hold for 30 I will straighten a leg)
I’d say it pretty much works the entire upper body. If you’ve read that gymnast article by Chris Sommer he states that his gymnasts build there arms thru static holds such as front levers, planches and iron crosses.