T Nation

Pulling Exercise, Biceps/Back?

On pressing movements, in lower phase is chest dominating and in upper phase triceps does more work. My question is about, pulling, lets take a chin-up/pull-up for example…

Lower Phase - From dead hang until elbows are at 90 degrees
Upper Phase - Elbows at 90 degrees until chin(head) over the bar.

when is biceps more working than back, when vice versa? And how does grip width and body angling change back/biceps involvement?

Interesting topic! I would venture to say that on pulling exercises it is about 50/50 in either range. Where on pressing movements it is more like 65/35.

I certainly feel my biceps at the beginning of a chin, because they are so stretched. But I feel them at the top of the movement too.

Interesting and difficult. On pressing, triceps works at top… the opposite of pressing is pulling. Biceps is the antagonist of triceps, maybe it works on the bottom part of movement? Makes that sense?

I was and am hoping for a exhaustive answer of this smart community here. I’m sure that the trainers, like CT and Poliquin can answer that, but I suppose they don’t hang in the forums…

The more elbow flexion you have, the more biceps activation you will have. That generally means that narrower grips will be biceps dominant whereas wide grips will utilize lats/rhomboids more.

On most exercises, once you get past the midpoint of the range of motion, you will begin to recruit more biceps due to the angle of elbow flexion. Your biceps continue to contract even after you have full lat/rhomboid contraction.

[quote]Mr.Y wrote:
I’m sure that the trainers, like CT and Poliquin can answer that, but I suppose they don’t hang in the forums…[/quote]

CT hangs out quite a bit from what I’ve seen. Some of the other authors are here a little less frequently.