[goodside]

I can do 50 push-ups. I'm not an athlete but I'm in shape enough to be healthy. I'm by no means "underdeveloped". I appreciate your concern -- thanks.

[Empact]

Great, but how much can you squat or deadlift relative to your bodyweight? Your posterior chain, from your mid-back down to your ankles, is far more important to your long-term stability and comfort.

It's key to your complaint of discomfort standing up, and it's key to avoiding back or knee problems long-term.

[antihero]

Pushups do use core strength to maintain your posture, but are mostly about upper body. How much can you squat or deadlift?