I can go really heavy on deadlifts or shrugs and get my traps destroyed for the next day or two. But my anterior, later, and posterior deltoids have never been sore to the best of my knowledge. My anterior deltoids are pretty big, and my posteriors are decent, but my laterals are like small bumps that are dwarfed by my anteriors. I've been doing heavy upright rows supersetted with light sets, lots of lateral raises, lots of experimental lightweight lateral deltoid isolation, but to absolutely no avail. I've even done 3 sets of lateral raises with 50 lb dumbbells started off with a jump and doing forced negative reps, but never even felt like I worked them the next day. I even did clean and presses with 160 for the first time ever in attempt to annihilate my shoulders, but of course no soreness and also no real growth. All other bodyparts I can make sore if I really try, and have no real problems forcing them to grow, but my lateral deltoids in particular are very stubborn. Any ideas? I've basically done all shoulder exercises I've ever heard of with high and low weight...