Please describe a hammer chin.
Please describe a hammer chin.
Think hammer curl type grip, except on a bar you pull yourself to rather than on a dumbbell.
Why does a chinup with a half prone grip work better than either a pullup or a regular chinup? If you want to leave out your biceps to work your lats more, you do prone grip regular pullups, and if you want to add biceps to the exercise you do supine grip chinups. Why is an intermediate form better? It may be easier because of your elbow lever arm length, but easier is not necessarily better.
I do them occasionally because of my choice of sport (jiu-jitsu). Pulling and grip/forearm strength (and endurance, for holding), is absolutely essential. I consider standard chins a "staple" movement, while I sometimes do hammer grip chins on the side. They put some of the forearm element of hammer curls into a far more useful movement.
Not something to be done to the exclusion of "real" chins, though, IMO.
Mainly it depends on your goals. I think it's worthwhile for many of us to train as many grips/variations as possible, like thickbar pull-ups, rotating bar pull-ups, ring pull-ups, towel pull-ups, kipping pull-ups, L-sit pull-ups, prone/supine/nuetral grip pull-ups, one arm pull-ups, wide, narrow, etc! I don't believe there is any one "best way" to pull our bodies up from a hanging position given the variety of physical obstacles that could fit the bill. These range from tree climbing, to wall climbing, to rope climbing, to sport climbing, to anything climbable. I relate this to the variety of ways that an object can be picked up off of the ground. Sure it would be nice to always lift things up with a straight back, but that isn't always practical, so it makes sense to train with a rounded back too. Ultimatley it needs to meet your goals though. So if you just want big strong biceps, do chins, but if you want to compete in Ninja Warrior or scale the Eiffel Tower, better train them all. And if you never have any ambition of climbing a tree or using gymnastic rings there's nothing wrong with that either.
The most important thing is identifying exactly what you want and then training to get it.
If you really want to work your grip, do chins and pull up using your belt (gi) or a towel.