Mention vibration and fitness and most people conjure up those useless jiggle belts women wore decades ago to try to shake away their flab. That visual image may soon disappear.
The Power Plate, a device about the size of a medical upright scale, sends vibrations through the body, promising to improve flexibility, strength, bone density and help heal certain injuries. Those claims have made true believers of some people and raised the eyebrows of others who caution that vibration therapy could have widely varying results for different people, and that long-term effects are not known.
The machine, developed in the Netherlands and used in several European countries for about four years, sends vibrations into the body. This causes muscles to expand and contract about 30 to 50 times a second and that, according to the manufacturer, causes an increase in blood flow, an increase in the release of serotonin (a brain chemical which can affect mood and hunger) and a decrease in stress-inducing hormones.
Users can just stand on the machine or do a variety of moves such as stretches, squats, push-ups and triceps dips. All can be done with or without free weights.
Some who have used it -- including personal trainers, physical therapists and athletic trainers -- say they, their clients or patients have experienced an increased range of motion, muscle growth and faster recoveries from injuries such as sprains. Not every change has been dramatic; some describe gains as “subtle.”
The Power Plate is being used in many health clubs around the country, as well as in medical and rehab facilities, universities and by sports teams such as the Mighty Ducks, the Miami Dolphins and the Oakland Raiders. The cost: $10,000.
In the medical community, vibration therapy has long been used to increase bone density (particularly in astronauts), but little is known about it as a workout enhancer or a way to help speed the healing of certain injuries.
A recent 12-week study done in Belgium looked at 67 women who performed knee-extensor exercises while on the Power Plate. The results showed their increases in isometric and dynamic strength and jump height were similar to those of women who did regular resistance training using weight machines. The study was published in this month’s edition of the American College of Sports Medicine journal Medicine & Science in Sports & Exercise. Research in the U.S. is just getting underway.
“When I became aware of all the applications, I saw there were two sides to this,” says Jerry Beckman, chief executive of Culver City-based Power Plate North America. “There was the potential of the machine versus the knowledge in the U.S. about vibration technology. It was clear we had to establish awareness before we made it available on a mass basis.”
Among the first to use it were pro sports teams. Brian Nguyen, head athletic trainer for the L.A. Avengers football team, says about 70% of his 40 players have used the Power Plate since December for everything from hamstring stretches to helping heal sprains and tendonitis. He’s noticed fewer major injuries -- four this year compared with 12 the year before.
Physical therapist Jose Fojas of Kerlan-Jobe/HealthSouth in Westchester believes some of his patients being treated for sports or orthopedic injuries have benefited in “subtle, positive ways,” such as reducing limps and improving range of motion. “It’s not a replacement, but an augmentation of [treatments],” he says. “I’m putting about 15% to 20% of my patients on it and we’re still in the evaluation process. It gives us a little edge, and that’s what we’re looking for.”
Donald Chu, director of athletic training and rehabilitation at Stanford University, finds the machine “a useful device” that’s developed a following among many of the school’s athletes. “Most of them felt a little looser when they got off it,” he says. “When used as a warm-up there’s a kind of arousal going on in the muscles, and when they were asked to perform strength training exercises it was easier to do them.”
But some are more cautious about the Power Plate’s benefits. Danny A. Riley, professor of anatomy at the Medical College of Wisconsin, has researched the effects of vibration on arteries and muscle tissue. Although he hasn’t had firsthand experience with this machine, after reviewing the research he is “cautiously optimistic” about it.
“It could potentially help muscle and bone,” he says, “but there are a lot of unknowns here. It could be a very useful adjunct to training if used properly, but what needs to be known is how to use it safely, since there is no data on long-term effects. More studies need to be done to really define the mechanism to know that it’s not damaging.”
The Power Plate is not recommended for people with acute migraines, serious heart or vascular disease, epilepsy, severe diabetes, acute fractures or fresh wounds. Others who should avoid it are those with pacemakers, pregnant women and people with recently placed metal pins, bolts or plates.
Beckman plans to establish centers soon which will offer short, efficient workouts on the Power Plate. He also plans to introduce it into senior living facilities. A less expensive (about $2,000) home version of the Power Plate is due in early 2004.