Original sentence: Effects described in the studies include: muscle strength and toning, cellulite reduction, improved bone density, heightened secretion of hormones associated with exercise, and depressed response of hormones associated with stress.One difficulty is that there are no recognized systems to rate whole-body vibration machines.Several hundred peer-reviewed papers have been published on the effects of WBV, and the number of research studies conducted every year is accelerating.Several inventions regarding whole body vibration devices have also been patented.Some machines are able to provide the benefits that are described in the studies, others do not.The effects are used in sports, fitness, aesthetics, rehabilitation and medical therapies.There are currently many whole body vibration brands on the market, and the quality may vary.Whole-body vibration platforms enable the user to train various skeletal muscles, and trigger other body reactions
Edited sentence: Currently there are few rating systems for whole body vibration machines.In 1996 the first whole body vibration device was patented on which the user could stand.One of the most well known systems is the Koehler rating system that takes into account the motor power, frame strength, integration of the control system and durabilty over number of uses.Research is still continuing all over the world in this still rather young but very active field of research.Since 1996 more than 100 peer-reviewed papers have been published on the effects of WBV.Some machines are very good and provide many beneficial results including muscle toning, cellulite reduction, improving bone density, and increasing muscle strength.There are also many cheap imitations sold on ebay that do not provide these benefits.There are currently many whole body vibration machines on the market.These devices enable the user to train almost every muscle of the muscle chain used for walking and are currently widely used in sports, fitness and beauty, and also for rehabilitation and medical applications