My game lags on iOS devices and not android

My game has a 2D character on which Sprite Animations are there which are player by Animation Controller. When a hindrace approches the character and we hit it, the hindrance which is a combination of various cubical pieces breaks down into pieces using AddForceAtPosition() in OnCollissionEnter. I have around 20 sprites in each animation of the controller.The hindrances are pooled, so there is no instantiation. My game works absolutely fine on Android device, but on IOS devices, I encounter frequent glitches, small but noticable. I am using Unity 4.6.6. What can be the possible reason of the lag?