@asperd I disagree with the influencer. The way the lats are attached to the humerus, if you internally rotate the shoulder that actually allows the lower fibers to pull in a straighter line and exert more force. The narrow handle also allows more activation of the stretch reflex in the lats.
One should also be driving with the elbows.
Ideally on a v-bar pulldown, one should pull the handle towards the sternum, and only go as far as maximum ELBOW range of motion. Flexing the arm to increase handle travel does not work the lats more-it simply works the arm flexors more.
Given the lats insertions and attachments, to work the majority of lat fibers, one would pull from a full stretch, then lean back to allow the handle to touch at about the xyphoid.
The elbow angle should not go much past 90 degrees.
If one wants to feel what a v bar pulldown should feel like, do a v-bar chin, and pull towards the sternum.
This minimizes arm flexion and maximizes the range of motion at the shoulder joint.
This isn't based on what the science says. This is the science explaining years of experience.
Regarding grip for lat work: If one analyzes, the same grip at different widths is more equivalent to other grips in terms of execution.
For example, a wide grip pronated pull up grip is the same functionally as a v-bar chin grip. In both cases, the hands are in a neutral position relative to the humerus. This is easily demonstrated by putting the hands in the position of a wide grip pronated pull up. Now move the elbows together as if you are doing a pec-dec flye, without changing the hand position. Your hands are parallel.
In the case of shoulder width parallel grip, this is actually the equivalent of a supinated grip with the hands close. This is the one that favors the biceps and will increase their recruitment.