Been lifting for 20+yrs have always touched my chest but with strong firm control. Never bounce did that once when i was 16 thought i broke my sternum. To those of you that have pain did you try a closer grip (shoulder width)? I will not go any wider than this for obvious risk of injury. 20 years and counting so far so good.
I make my elbows at 90 degrees and then go back up. on flat benching i watch it closely that's where most shoulder injuries happen I've read in relation to the bench. I don't incline much, I use dumbbells there. on decline it's the same thing with my 90 elbows. I feel my chest the most without a lockout or pause at the bottom and that's what is important to me.
Shoulder injuries on bench are not a result of depth, rather the angle of the humerus in relation to the body. If your humerus is 90 degrees with your rib cage, the shoulder joint is compressed and more prone to injury. For a BB, about 45 degrees is optimal and for most PL's the humerus stays adjacent to the rib cage for minimal strain on the shoulder joint. With that said, I always touch my chest. Touch, never bounce. If you have an injury, then train how you must. But off the chest is the full measure of bench strength. That's why I fucking hate listening to guys talk about how much they bench and then they pull some "elbows at 90" horseshit. Maybe we should only squat to 45 too. My 2c
With chest, before i even pull the bar off, I make sure my shoulders a back, then i always move the bar slow and controlled coming down to about 1/2 in above my chest. I find if i bring it all the way down, i relax the muscles, then use to much shoulder for the push back up.
i touch in the beginning and at the end to get a good stretch --once the weight climbs i stop short as i feel it puts to much emphasis on the shoulders and takes it away from the chest ... i dont bench very often i mainly stick to incline movements but do the same for them aswell -- first couple sets i touch to get a good stretch .. go heavy then pull for one more stretch set