Whole-body vibration is pitched as a solution to everything from low bone density in astronauts to a better golf swing for weekend duffers and as an aid to rehabilitating weakened muscles. But a small new study suggests that regular training using whole-body vibration does nothing to improve muscle strength or function in patients with multiple sclerosis (MS).

The technology has been increasingly used as a treatment for muscle-related diseases such as MS because the vibration is thought to stimulate muscles to become more efficient and to build bone.

In the U.S., an estimated 400,000 people have been diagnosed with MS, a condition affecting nerves and muscles that typically begins manifesting itself between the ages of 20 and 40. Characterized by progressive muscle weakness and loss of control, the course of the disease can vary widely between individuals but may eventually become debilitating.

In the first long-term investigation of whole-body vibration in MS sufferers, Belgian researchers looked for an effect on various measures of muscle capacity in the upper legs, including strength, function, endurance and speed of motion in 11 men and women with mildly to moderately disabling disease.

Volunteers performed leg exercises, such as squats and lunges, on the vibrating platform during five sessions every two weeks for 20 weeks. Meanwhile, another group of 14 MS patients was asked to go about their daily routines.

The two groups began the study with similar levels of weakness in their legs, and after 10 and 20 weeks of follow-up that hadn’t changed, according to the researchers. The lack of any effect of from the regular workouts was somewhat surprising, the scientists added, because studies have shown that MS patients benefit from regular exercise.

“Under the conditions of the present study long-term [whole-body vibration] probably does not improve upper leg muscle strength and functional capacity” in people with mildly or moderately disabling MS, the researchers wrote in the Journal of Rehabilitation Medicine.

Although the results found no benefit from vibration therapy, the researchers said their study might have missed such an effect for several reasons. It’s possible that the small number of patients prevented them from detecting improvements in muscle function. Similarly, every patient performed the same exercise routine, so it’s impossible to say if a customized regimen would not be effective.

Tom Broekmans, a doctoral student in physical therapy at Hasselt University in Diepenbeek, and leader of the study, added that the patients in the trial may not have been disabled enough to reap gains from the vibration treatment. However, patients who are too weak can’t perform the exercises, he said, creating a tricky paradox for researchers hoping to study the issue.

Dr. Nicholas LaRocca, vice president of health care delivery and policy research at the National Multiple Sclerosis Society, said his group does not endorse particular technologies but does stress the importance of exercise for people with the condition.

“Exercise is really considered to be very beneficial for people with MS, particularly if they can avoid overheating,” Dr. LaRocca said. Not only does aerobic exercise build strength, he said, but some evidence suggests that it may improve the immune system in MS patients.

Few effective treatments exist for MS, and none can cure the condition.

As for whole-body vibration and patients with MS, Dr. LaRocca said, “maybe additional research needs to take a closer look at who would be most likely to respond, if anyone,” to the treatment.

SOURCE:  Journal of Rehabilitation Medicine, October, 2010.