Currently I don’t do any bicep work but my biceps have grown from just doing back work. I thought about adding bicep work but I don’t want to hurt my back development.

“Pull from the elbows when training back.”

Also, at the perceived far end of the movement ie when your elbows lock straight, the movement has figuratively “just begun” as far as building your back goes. The pivot point shifts from your shoulder joint to the sternum-clavicle joint and then the shorter range higher torque muscles are awaiting. EG during lat pulldowns (which actually hit the teres muscles more), as you allow the bar(also dadgumit if you’re going to do wide grip pulldowns, get your pinkies all the way out to the end of the bar!) as you allow the bar to move toward the ceiling, when your elbows lock straight, look at exactly where the weight stack is and relax your back  while pushing your neck backwards. The weight stack Will move some more downward X inches.  Eventually X increases and that’s what really hits the back.   Be sure to warm up thoroughly for this by doing this at lighter weight higher reps first. Min reps on the heavy sets should be 12. Any less than this and you’ll tear tissue. Warmup with 1/4th weight for forty eight, and then 1/2 weight for 24 then 2-3 sets of “the weight” 12-15 reps.

hope this helps.

train lower abs not upper. upper ab training induces kyphosis, pulling your upper rib cage forward and leaving airspace between the shoulderblades under your shirt. get the clavicles forward and keep them forward, ok maybe not 100% like captain America, he looks like he fell off a clothesline, but keep the clavicles forward. Grab two pencils end to end – max width is achieved by those pencils being in a straight line, Not back and up like most guys clavicles.  forward and down forward and down to     straight across for max width.

Wide grip low cable rows, period. Do Them.