Unusual Chest Pain

A long time ago I tried a muscle up on rings for the first time and my sternum "popped", there was no pain at the time or afterwards. It felt like it was just the joint moving some and reaching some new places in its motion. Maybe even a rib moving in its acceptable tolerance. From that day on my chest has popped every so often. Then, some time later I was doing weighted ring dips and did not keep good tension at the bottom of a rep and went to far down in a big chest-stretching sort of motion. That hurt. It hurt to do any kind of non-overhead pressing (hspu, btw got my first ugly full rom rep the other day). Pushups, dips, leaning forward on my arms would all give me some small pain in my chest. There was no bruising and maybe even no tenderness. Eventually, I saw my chiropractor and he gave me a rib adjustment and I felt better, he examined me and said at worst it was a micro-tear where my muscle connects to my sternum; and that it was the worst injury I could have that rest would fix. Fast forward to today. I no longer have the pain when pressing. It still pops often, maybe feels like a rib. I can just "feel it", no pain or anything when in a handstand or anything like that. I have been rehabbing it with ring pushup variations and ring dips and have never stopped doing any kind of hspu this whole time as they never caused me pain, though I could "feel it".

Anyhow-here is the thing: Imagine you are holding a kettlebell (or whatever) with both hands on the horns, arms flexed, in front of your chest, just like you are holding something, anything really. That is when I get the most pain or tightness. Now, it really is when the object is close to the chest that hurts the most, like a front plate raise does not seem like it would stress it as much as just a close to the body hold.

Does anyone have any insight as to why this is and what exactly is going on in my chest? And, perhaps so rehab suggestions? Does this seem unusual to anyone? I have not seen my chiropractor since my wife quit working there, perhaps I should return...

You actually have a pec strain at the sternum. Not terribly common, but it can happen. Massage, working with weights and exercises that don't hurt, and slowly scaling back up to pre-injury levels. Cable flyes will definitely help but start LIGHT! Chiro will help if some ART is done somewhat gently. You can do cross friction massage on the area as well, but not more than 2 minutes at a time and not more than 2x per day, spread out morning and evening.

Plate raises don't hurt because that's much more deltoid than pec, and the pec fibers that ARE working are mostly attaching to the collarbone and not the sternum. Try that bent arm hold with like a 5 lb kettlebell, dumbbell or plate, pressing in some with the hands. Slowly add weight as you continue to do isometric holds for 20-30s.

My sternum pops occasionally but it is completely pain free and fairly infrequent. Usually happens when I take a super deep breath and arch my upper back. Not the same as yours I don't think!

Edit: with cable flyes you need to have your hands more or less in line with the pulleys. This means you will start out between or behind the pulleys slightly. Don't stand in front like you see everyone do... that's going to make it easy where you need it to be difficult, at the end of ROM near your chest. Try to keep straight arms. Upper arms need to be parallel with each other at the end of each rep, more ROM is fine but less is not.