videos.bodybuilding.com/video/6892/the-fit-show-season-one-episode-3-milos-sarcev-chest-trainingWith the elbows closer to the body, you put emphasis on triceps
With the elbows further from the body (90degrees), you put emphasis on Chest
With chest/back flat on bench, you put emphasis on shoulders
With chest raised/back Arched, you put emphasis on chest
With wider grip, you put more and more emphasis on outer chest.
With closer grip, you put more emphasis on inner chest and triceps
Lowering the bar to the stomach, stimulate lower chest
Lowering bar to towards the neck, stimulate upper chest.
As you can see, there are loads of combination to put more stress on specific muscle.
Of course, naturally if you have a close grip, your elbows will also be closer to the body, therefore Tricep stimulation.
To simplify the information, I will just talk about Standard (forearm parallel to floor) grip in the following comments:
In the MuscleTech DVD "The Trilogy", Charles glass explained that the difference between POWERLIFTING benchpress and BODYBUILDING Benchpress is that
Powerlifting: slightly closer grip(still standard grip), lower bar to lower chest
Bodybuildin: slightly wider grip(still standardgrip), lower bar to upper chest (around clavicles)
So if you're going to do a "45degree" arm benchpress, it would simulate "powerlifting style". The wider you start to grip the bar, the more your upper arm will head towards "90degrees". At the same time, once you grip wider, you will also be forced to lower the bar higher up the chest, therefore changing which area of the chest you will stimulate more (upper, middle, lower).
This explanation is in agreement to what Charles Glass said in the MuscleTech Dvd. Bodybuildin style: Wide grip, lower to upperchest.
However, the higher up your chest you lower the bar to, the more stretch overload you can give your pecs. I personally believe this is not safeReason is because i heard stories about pectorals tearing, or shoulder joints giving out because of the "extra range of motion" you're allowed.
Because of this, I personally lower the bar either right above the nipples (being the highest i go on flat benchpress), or below my pectoral line ( the lowest i go on flat benchpress). If I Arch my back and expand my chest (which you should be doing to allow chest to work instead of Front delts), I noticed that my arm bend degree is about 90 once the bar actually touches my chest. I believe i have about 15degrees more to go before my maximum range of motion for pulling my arms back is reached.
Also, according to International Powerlifting Federation (IPF) rules:
2. The lifter must lie on his back with
head, shoulders and buttocks in contact with the bench surface. The feet must be flat on the floor (as flat as the shape of the shoe will allow). His hands and fingers must grip the bar positioned in the rack stands with a thumbs around grip. This position shall be maintained throughout the lift.
So 4 points of contact (head, shoulders, butt, feet)
I hope this helps.
