Medically reviewed by Amy Kwan, PT Your latissimus dorsi (your "lats") is a broad, flat, triangle-shaped muscle that spans ...
Just like you shouldn't skip leg day, you shouldn't totally ignore focused arm training in a misguided effort to avoid looking vain. Training your arm muscles ... the movement. Lower the weight ...
It plays a role in many arm movements and supports respiratory ... and tight over time. As the muscle fatigues, you may feel pain in your lower back or under or around your shoulder blades.