Shoulder pain cleared up by push-ups.

I climb a lot. I never do push-ups. Recently my shoulder started hurting. At the suggestion of my friend, I started throwing in between 2 sets of 20 push-ups after a work-out. Miraculously, the pain cleared after two days of doing this. I'm just wondering if anyone knows what the source of the initial pain would be in the shoulder that can be rectified by push-ups. Is it arthritis? Is it a muscle imbalance? Obviously, I'm going to keep up with the push-ups, but if this can be the sign of worse things to come, I'd prefer to deal with it now than waiting until it really manifests.

Probably muscle inbalance in the shoulder. I'd add some scapular exercises and rotator cuff exercises using a theraband or similar. Nothing crazy, just a session or 2 per week. Maybe some general shoulder exercises also, making sure you hit all 3 deltoid regions. Push-ups help but they don't specifically target the correct muscles as well as these more specific exercises do. I'm not a doctor or anything but I've had some serious shoulder issues over the last few years.