A scapula is the flat, triangular bone in your upper back, one on each side of your spine. You probably know it better as your shoulder blade: if you reach over your opposite shoulder and feel that broad, flat bone under your skin, that's your scapula.

Each scapula helps connect your arm to your body. When you reach up high, throw a ball, or do a push-up, your scapula glides smoothly across your back, working with seventeen different muscles to give your shoulder its incredible range of motion. Your shoulder is actually one of the most flexible joints in your body, and the scapula makes much of that movement possible.

Doctors, physical therapists, and coaches use this anatomical term because it's precise: saying “scapula” means exactly that specific bone, while “shoulder” could refer to several different parts. If you've ever done an exercise like a scapular push-up, you were specifically working the muscles that control how your shoulder blades move.