Exactly! Many moons ago my pitching coach, an active major-league pitcher, told me that the slider, when thrown correctly, is actually easier on the arm and shoulder than almost any other pitch. And unless you have a large hand and long fingers you should steer clear of the splitter---the grip puts too much of a strain on the muscles of the forearm. You could, however, if you want to add that pitch to your repertoire, use a modified grip---as for a two-seam fast ball, but spread the index and middle fingers enough so that they're just on the outside of the seams, and throw it like a fast ball. As for the slider, here's what my pitching coach told me: "Throw it like a curve, but roll your wrist, don"t snap it."
The grip he showed me, and which I used, was off-center---neither two-seam nor four-seam, but in between, with the index and middle fingers close together, the thumb on the bottom and the other two fingers on the side of the ball. As to how he threw it, and what he showed me---you know how you throw a curve ball, like a karate chop or pulling down a window shade? You do that, but you don't snap your wrist; you just turn it over. It's a lot easier on the arm, and if you still have a problem you'd better have a doctor check it out. I believe the problem is unrelated to what you're throwing.
Good luck. 8)