Wide Grip Lat-Pulldowns or Wide Grip Pull-ups
will focus on the rear delts, teres major, middle traps, and other mid-back muscles more than other grips. *This will get your mid-back more defined.
A Wide Grip Lat-Pulldown where the bar slants upward at the end (imagine an upside-down lat-pulldown bar that does not rotate) will focus even more on the mid-back and the external rotators/rotator cuff area.
A Palms-in Grip or Chin ups will focus more on the Lats than wider grips. It will also focus more on the biceps than the teres major. *This will get your lats bigger.
A Neutral, Palms Facing Grip with a moderate grip length (about the length you bench with) will allow you to use the most weight. I would recommend using this kind of attachment or pull-up bar whenever possible.
A Close-Grip (the kind that’s usually found on the Low Cable Row) will focus mostly on the lats not so much on any other mid-back or arm muscles. It won’t allow you to use as much weight as a wider neutral grip, but it focuses on the Lats the most.
I think for Lat-Pulldowns or Pull-ups you should usually use the grip that allows you to use the most weight. If you do your rear-delt work and your curls, you don’t really need to worry about it too much.
I also think that the Hammer Strength High-Row Machine is superior to the Lat-Pulldown as it isn’t very demanding on grip strength and I think it works the lats through a fuller range of motion because it makes the elbow come closer to the torso than lat-pulldowns or chins. Sure, you can bring the elbows almost as close to the torso if you touch the chinning bar or the pulldown bar to your chest, but if you’re doing that then you probably aren’t using enough weight and you’re one of those tiny people whose just training for the “pump” and the “feel.”
Chins, Dumbbell Rows, and Barbell Rows are still superior to the High-Row.[/quote]
FightingScott, very well put. Mike Mentzer had been saying for years that close grip pull ups are superior for lat width because of the stretch even though the trend was always to grip wide. I think people assumed the wider the grip, the wider you will become.