Animation won't stop when the player isn't moving?

I'm trying to get an animation to not play when the player is standing still, but I can't seem to get it to work.

spawn(function()
    local Event = Human.Running:Connect(function(speed)
        if speed < 0 then
            RunningAnimation:Stop()
        elseif speed > 0 and not RunningAnimation.IsPlaying and Running then
            RunningAnimation:Play()
            print(speed)
        end
    end)
end)