What is LaBrum?

Boy or man who complains about his shoulders all the time. And says things like "I don't know about my shoulders"

I DONT KNOW ABOUT MY SHOULDERS MAN GUESS YOU CAN CALL ME A LABRUM BOY

LaBrum - meme gif

A muscle located on the shoulder that is often confused with the clavicle muscle

While playing swimming pool basketball, I received a devastating blow to the labrum!