Question for the biomechanics gurus -
Which muscles are more active during the first portion of the pull-up (from arms extended to 90 degrees), and which are more activated during the finish (from 90 degress to chin over bar)?
By 90 degress, I mean the angle between upper arms and forearms. That's been a sticking point for me when going for personal best.
To many variables to give a definate blanket statement. grip width, bodhy lean, the individaul, how you pull etc.
In general id say the first half until the arms are at a 90 degree angle is largely biceps, then if you are to pull through the elbows squeeze those lats etc its largely your upper back musculature. etc..
Is that what your looking for??
Yeah, I think so. My biceps are decent, my lats are not very wide. Guess that means I should do partials at the top of the pull-ups to build my lats.
Well I wouls stick to the full ROM and just aim to use the back musculature. Make sure you are using the back to pull not the arms. squeeze that back. Things that help are thumbless grips, a bit wider grip maybe. pull through the elbows, really get a squeese at the top and push that chest Through your back toward the bar.
Maybe king O' pull up will stop by and add a bit more, ZEB????
Yes, grab the bar, look up and lean back. Try to imagine you are attached to the bar at the elbows and pull to the chest.
contrary to popular beleif, it is your biceps. at 90deg your body is furthest from the bar ( if you look sideways) loading maximally the biceps (physics leverage) which are more active in the chin up at that position. It's the same thing is bicep curls usually you'll stick at 90.
So altho you think your biceps are strong, they aren't as strong as your lats in this movement. So use pauses or oscilating techniques or whatever else to strengthen the biceps at that sticking point.