Asymmetrical bench grip

[CSilv2016]

I am helping a friend get started with linear progression. He is 62 years old, and he had been lifting on his own (not SS) for about a year. He asked me for help with form because he was having some shoulder pain when benching and pressing, and because he was stuck at relatively light weights.

I got his press straightened out without anything too unusual. (He was pressing with an almost bench-wide grip on the bar, among other things.)

But I ran into something that I haven't seen before on the bench (and I couldn't find anything in the search of the forums).

At the bottom of his bench, with the center-knurl dead center of his chest, with the appropriate elbow angles (65-ish degrees), and with perfectly vertical forearms from the front and side view, his hands are at asymmetrical distances from the center of the bar. His right hand is at what I would consider to be a normal bench width for his build, but his left hand is closer to the center of the bar by about an inch. If he uses the same grip width for his left hand as his right, the left forearm is angled out towards the weights from the front view, and the elbow angle decreases as the elbow is closer to the body.

The pain he was experiencing was in his left shoulder, and it went away completely when I had him use the asymmetrical grip width, so I told him to do that for now.

My questions -

1. What would cause this?
2. Should he continue to use the asymmetrical width, or should we be working to make it more uniform?

[Nick Delgadillo]

Maybe a shorter humerus or some weirdness in the shoulder. Without seeing him, my pulled out of my ass advice would be to have him do that which causes less pain and gradually work him toward a more symmetrical grip. If his back/shoulder/arm is sufficiently messed up that strengthening whatever is messed up doesn't fix it, he'll just have an asymmetrical grip.

Or he can just press if it's a major concern. I'm quick to dump the bench on older folks whose joints get pissy from benching.