prime mover in a barbell row is the rhomboids. i'm not a huge fan, despite dorian and Ronnie's endorsements. methinks they would've grown off of jumping jacks. I don't see how the angle you see bbers do it (70deg's) engages the "lats". it defies physics... or the bbing equivalent of 'physics'. lol.
you're basically doing a 45-70deg bent over powershrug/quarter-deadlift .
try sitting up in your chair and putting your right arm overhead with a reverse grip and pulling down/flexing while holding your fingers/hand of your left hand on your right lat... fell it contract? now stand up and lean forward in the same angle you would with a bend row and do the same thing... feel your lat contract? I don't... I the other muscles in the upper back contracting, but not the lat.
disagree..... it's a big MMC lift in my opinion. If you do it right, the upper arm moves exactly like it would in the last 1/3 ROM of a nautilus pullover. Going too heavy ensures every muscle BUT the lats move the weight. Lee Haney knew what was up, he wouldn't go over 185 or so.
Anabolic, stand up straight holding a bar loaded w 1plate/side w an underhand shoulderwidth grip (overhand is safer, but it's easier to"feel" the lasts w underhand). Slowly bend over until you feel a stretch in the lats. Keeping elbows tucked, pull the bar somewhere between your navel and sternum. Stop an inch or so shy of actually touching your stomach.
Keep your hands as loose as you can and think not of pulling the bar up, but pulling your elbows back.
Start light, you've mastered the form/feel, only then go up in weight.