The reason why many people perform behind the neck lat pull downs is to bring the upper lat into play a little bit more, but whether this actually makes enough difference to warrant the extra risk of injury (specifically impingement) in the shoulder is debatable. I’d go as far to say that this variation of the lat pull down causes more damage than good, and shouldn’t be performed under any circumstances, and certainly not with a heavy weight!
Where’s the sense in doing them?
They look awkward when performed and reduce the weight you can pull despite attempting to recruit the same muscle as regular lat pull downs. Both behind the neck and front lat pull downs work your latissimus dorsi (lats), the back muscle that gives that classic ‘V’ shape in well muscled body builders and athletes. Therefore it makes little sense to increase your risk of impingement syndrome, a condition where the muscles or tendons of the rotator cuff become trapped in your shoulder joint.
Risk of injury
The shoulders are a relatively small muscle group which are not designed to lift the sort of loads the lats are capable of. The shoulders are a secondary muscle used during lat pulldowns, but the movement cannot be performed without them, consequently massive loads can be placed on the shoulders and rotator cuffs (stabalising muscles deep in the shoulder). By bringing the bar behind your neck you are opening the shoulder joint up slightly which exposes the muscle and tendons to becoming entrapped within the shoulder joint.
Target your back muscles in different ways
If you want to increase the width of your back i.e. the ‘V’ taper, then perform pull movements such as wide grip pull ups and in front of the head lat pull downs. Conversely should you want to increase the breadth of your back, then perform row movements such as the single and double armed seated rows. In order to target the middle back you should consider exercises such as bent over rows, these will bring the back into balance giving an overall improved aesthetic.
Don’t run the risk!
Play it safe guys and girls, stick to the regular lat pull downs bringing the bar down to between your clavicle and nipples (middle of the chest) in a smooth motion. Jerky movements at speed will increase your risk of injury, so avoid using momentum to thrust the bar down during the positive phase of the motion because one slight change in angle whilst at speed will significantly increase the risk of impingement, strains or misalignments. Whether you choose to perform behind the neck lat pull downs is of course your decision, many top athletes occasionally incorporate behind the neck lat pull downs into their routine. Steve Cook and Rob Riches have been known to perform these moves, but they have a solid foundation of muscle, are well conditioned to perform these moves, and will not be lifting anywhere near the weight they can when performing regular in front of the head lat pull downs. So perform them if you wish but do so with caution…and if you want my advice from experience, STEER CLEAR of them, they’re not worth the risk!