All about the linear vibration technology
Power Plate, one of the pioneers of the vibration technology, had introduced a strictly up and down motion among vibration machines. This up-and-down motion is what is known as linear vibration.
With passing time, there have been more modern technologies, that have surpassed and subsumed the capabilities offered by the linear vibration machines. Even Power Plate no longer has a true linear vibration machine model, to the best of my knowledge. They have replaced by a more modern and wholesome technology, named tri-planar. However, there are still some machines found in the market that are truly linear in nature.
As I mentioned earlier, the linear machine will be a strictly vertical one. The vibration plate will move up and down, and will help you get exercises accordingly. The impact is high on the body, and will be great if you are doing muscle building. On the flip side, if you are not too healthy, it will have a jarring effect and will be hard on the body.
Note that if the machine is set on the lower frequencies and amplitudes, it ought not be a problem. The stress becomes higher at the higher vibration frequencies (but may be a good idea for body building). In fact, as you go all the way up from the lower range of 2 mm of vibration amplitude to the higher range of 12-14 mm, it will exert a lot of pressure on the muscles and knees, and in general may get a bit too hard on the body. I have explained amplitude and frequency on this and this page respectively. Essentially, frequency is how hard you vibrate (how many times you go up and down per second) and amplitude is the amount you vibrate (in case of linear, how much you go up and down every time).
Linear machines are ideal for those who want to do body building, and budding athletes who would want to make large muscle gains at the fastest possible rate. These machines, though, can be somewhat hard on the body, and can be counter-productive at times (do more harm than good) if used too hard or used without limiting oneself to the purpose that it was meant to be used for.
So if you have already chosen a machine with this technology, double-check that you really want it, or would be better with a tri-planar vibration machine. Clearly, those machines are the future and linear technology is generally more on the back seat now. I don't see that changing, and in my experience, this is all for a good reason.
I promise to have the lowest prices anywhere, for all brands and models. If you find a machine listed at a lower price within 30 days of purchase from me, I shall refund what you paid extra. Call me before you buy (1-888-228-4387) and ask for the lowest prices. You will save at least $200-$600, if not more. I am not permitted to advertise those prices online, not even with coupons, so call me up or write me an email.