Mine don't kick. My evaluation dr looked shocked. Tried second leg. Then looked puzzled. Then hit me harder 3 more times. Told him that was painful enough and he quit trying. Told him 3 hr car ride to get there fucks up my back. Guess I made a believer out of him, he told me I needed to get a desk job. ( I am retired)! Sitting is what fucks you up with bad back and hips.