Fire Kid

[Hoeloe]

That wasn't what I was saying.

For one thing, hugging the arms close to your body DOES work for this kind of running, you just didn't animate it well. You're treating the animation as existing in 2D space as a cardboard cut-out. That is not the way you should animate. Notice that the forearm in Metas example shortens during the animation, to simulate it bending away from the player. The reason yours looks wrong is because you've tried to replicate that by simply sticking it out in front. That's not how it works.

As for the shoulder, it's not to do with colour and shading. The fact is, your character's chest as it currently stands is stretching due to the fact that you have moved one shoulder and not the other. You don't have to show your character's back during the animation. You can quite easily get away with only a little bit of twisting, but you've put a lot into one shoulder, and none at all into the other. Try doing that yourself. Move one shoulder back while keeping the other one completely still. Now tell me that's a natural thing to do while running.

Honestly, the best way to animate a human is to act out the poses yourself, and pay very close attention to the position of all your joints.