How to fix the arms in one place?

So this is my code at the moment, and it works fine. However, the left arm isn't in a fixed position, it moves as the character walks. This is in a tool and local script.

Also, when unequipped, I can't seem to get the arms to go into their original position.

Thanks in advance.

local rs = char.Torso['Right Shoulder']

    rs.C1 = rs.C1 * CFrame.Angles(math.rad(-10), math.rad(-5), 0)
    rs.C1 = rs.C1 * CFrame.new(0,-0.7,0.2) --Y, X, Z

    local ls = char.Torso['Left Shoulder'] 
    ls.C1 = ls.C1 * CFrame.Angles(math.rad(-16), math.rad(0), math.rad(90))
    ls.C1 = ls.C1 * CFrame.new(0.5, 0, 1.3) -- x y z