Do experts recommend the use of whole body vibrations?

I believe you are referring to whole body vibration or WBV.  While I believe the final verdict is still out there is a lot of evidence to support their use.  I use WBV with most of my clients to one degree or another with great success.  WBV has shown to benefit bone density, increase exercise intensity, increase caloric burn rate, plus reduce pain and inflammation.  WBV is a very effective tool when used appropriately.  There are contra-indications that you will want to be aware of so get proper instruction before using.

I have found the WBV to be very effective for flexibility, range of motion and recovery.  Many times holding a stretch on the WBV or applying a foam roller can deepen the stretch or increase the neural response increasing the range of motion.  This may not be wise before strenuous or performance activities but would be perfect post training for improving range of motion from tightened muscles and improved recovery.

As mentioned above it can be great for circulation so light use before exercise can help improve blood flow and prepare the body for exercise.

In addition it is very difficult to do movements while on the machine and in use.  Doing exercises (while monitored) can be extremely helpful because it increases the neural excitability and improves a persons proprioception.  Increased blood flow and range of motion can be very beneficial but in my opinion the improved proprioception is probably the biggest advantage.

What is proprioception?

It is the input to the central nervous system from the sensory receptors that are responsible for the input from the position and movement of limbs.  When you move or change position or the stabilization in your surroundings these receptors send signals to the central nervous system.

When proprioception is improved your are more efficient in changes in position or stabilization of surroundings.

i.e. - you improve your balance and stabilization.  

Whole body vibration is still very new and is not endorsed by all experts within the health, fitness, and medical fields. There are many researchers and studies currently being done on whole body vibration and its benefits for a variety of health, and fitness related issues and many experts who recommend it, but at this time the whole body vibration method is not universally recommended by all experts.