Script that makes the player's right arm not correctly positioned after animated. How to fix?

This script is for a animation and I want to make it so it returns to the normal character's look rather then the arm getting more twisted for a weird reason.

player = game:GetService("Players").LocalPlayer
mouse = player:GetMouse()
character = player.Character
debounce = false
mouse.KeyDown:connect(function(k)
	local key = k:lower()
	if key == "e" and debounce == false then
		local torso = character:WaitForChild("Torso")
		local rs = torso["Right Shoulder"]
		debounce = true
		for i = 1,10 do
			rs.C0 = rs.C0 * CFrame.Angles(0, 0, 0.18)
			rs.C0 = rs.C0 * CFrame.Angles(0, 0.15, 0)
			wait(0.025)
		end
		for i = 1,10 do
			rs.C0 = rs.C0 * CFrame.Angles(0, 0, -0.18)
			rs.C0 = rs.C0 * CFrame.Angles(0, -0.15, 0)
			wait(0.025)
		end
		debounce = false
	end
end)

Should I substitute something? Use another instance? Also if you could give me a related wiki reference page associated with your answer, that would be nice!