Wednesday, March 2, 2011

“Magic” Wristbands Exposed

Many professional soccer, baseball and basketball players can now be seen competing while wearing small, multicolored wristbands. These bands are advertised to improve performance by improving the body’s balance. At the heart of these wrist bands is a small disk of Mylar that is supposedly embedded with naturally occluding frequencies that resonate and align the body’s energy flow. Commercials litter television and the internet advertising how balance and strength are improved by wearing the Power Balance®, iRenew®and Q-Ray® wristbands. The demonstrations are convincing. Celebrity endorsements also claim that athletic performance is increased. Do these wristbands actually work? A new study from the RMIT University in Australia is one of the first to critically examine if they have any effect on balance. Using a tightly controlled research design, the researchers show that the effects of Mylar holographic wristbands may not live up to their hype.

The study enrolled 42 subjects (19 men and 23 women). Each subject reported to the laboratory on two occasions for a series of balance tests. On one occasion (Trial 1), the subjects first performed the tests using the Power Balance® wristband which contained two Mylar holograms. The tests were repeated a second time without a wristband and a third time with a placebo wristband. On a separate occasion (Trial 2), the order of treatments was reversed – placebo, no device, followed by Power Balance®. The order of the trials was randomized so that some subjects performed Trial 1 on day one and the others Trial 2 on day one.

The placebo band was designed where the two Mylar holograms from a Power Balance® were removed and replaced by stainless steel disk with the same dimensions and weight. Both wristbands were then covered with tape and turned inside out. This insured that the subjects could not distinguish which band, the placebo or Power Balance® was being used on which day (a concept referred to as “blinding”).

The results showed that there was no improvement in balance when using either the Power Balance® wristband or the placebo band. In fact, the trend was for the Power Balance® band to decease balance in one of the tests. However, the statistical analyses used limited how confident the researchers were in making this claim. Thus, when he Power Balance® wristband was used in a tightly controlled, blinded study, there was no effect on balance whatsoever. This finding also brings into question any claims that athletic performance is improved by wearing this device.

So why do these wristbands work on the commercials? The demonstrations shown on TV or the internet are classic examples of what researchers call an order effect. An order effect occurs when performance is improved from one test to the next simply because he subject is more familiar with the task during the second trial. For example, if a math teacher gave the exact same test two consecutive days, scores on the second day would almost assuredly be higher than on the first. In the product demonstrations, the tester first tugs on the subjects arm while he is not wearing the wristband. This disrupts his balance and causes him to stumble. During this initial trial, the subject is unaware as to what to expect or how to react. For the second trial, the wristband is used. The tester again tugs on the subjects arm. This time, the subject is aware of what will happen and is prepared to stabilize himself. As a result, the wristband miraculously improves the subject’s balance! This approach is no different than re-taking a math test while wearing a hat. The improved score could be attributed to the hat somehow aligning the body’s analytical brain waves and mysteriously improving math skills. In reality, the effect is simply repeating the test.

There is no doubt that if the wristband was worn during the first trial of the demonstrations, the result would be the exact opposite – the subjects balance would be improved by removing the band from the wrist.

Many of the strength tests used demonstrate how torque affects one’s ability to resist a force. Torque is defined as a force multiplied by a distance. In another version of the test, the subject stands with her arm extended and the tester applies a downward force on the arm. Here torque is calculated as the amount of force applied times the distance from the shoulder. The further along the arm the force is applied, the greater the torque. In the first trial, the tester applies force near the wrist. The subject has a difficult time resisting the applied torque and the arm is pulled down. In the second trial, with the wristband in place, the same force is used but it is applied nearer to the elbow. The positioning of the force closer to the elbow results in less torque being applied. As a result, the subject is able to resist and keep the arm extended. Thus, the wristband has miraculously improved strength. In this case, simple physics has demonstrated an effect.

In both demonstrations, the effects of the wristbands on balance result from design of the tests. By manipulating the order of the trials and applying some simple physics, the demonstrators are able to show that balance is improved. Unfortunately, the results have little to do with aligning the body’s energy flow or correcting its natural frequency.

What about the Mylar disk embedded with natural frequencies? Mylar is a polyester film that is used in a number of products. The most obvious is the security hologram on many credit cards. From a physics perspective one cannot embed a piece of material such as Mylar with a frequency. Add to that, that the “body’s natural frequency” is a concept that really has no meaning. To put it bluntly, the body does not resonate, vibrate or oscillate in any manner that can be corrected. Membranes like eardrums do vibrate with sound but the body, as a whole does not. So the entire concept of these wristbands aligning the body’s frequency has no basis whatsoever in either biology or physics. It’s no wonder that the Australian study showed that they had no effect on balance.

What about the testimonials? Many athletes claim that they work. Are they wrong? The “placebo effect” can be very strong. If you truly believe something helps you play better, it might. Wearing a wristband might give you an added boost of confidence. Play well in a few games with one on your wrist and you might be convinced you that it is truly special. Leave it at home one day, doubt creeps into your mind and you play poorly. This aspect of human psychology effect can be very powerful in some athletes. However, the placebo effect has no basis in human biology and wearing a Mylar embedded wristband is no different than carrying a lucky rabbit’s foot.

The marketing of these devices is also filled with a lot of pseudoscientific jargon and half-truths. One manufacturer states their wristband “will not make you stronger than you are but as strong as you should be...” It’s not clear what this means but it sounds impressive. Terms like frequency, resonate and energy flow also sound scientific but in the context of the product ads, their meaning is very vague. In fact, one website writes that some of the statements made by these companies “are so incoherent, so at odds with scientific knowledge, that they aren’t even wrong.” A strong indictment. In fact, the Australian Competition and Consumer Commission found Power Balance mislead consumers. Power Balance was forced to place on its Australian website the following statement: “We admit that there is no credible scientific evidence that supports our claims and therefore we engaged in misleading conduct in breach of s52 of the Trade Practices Act 1974” and offer refunds to purchasers.

In the end, once one cuts through the jargon and pseudoscience, it’s easy to see that the “science” behind these wristbands have little to do with improve athletic performance.

While the commercials and celebrity endorsements are impressive, claims of increased balance and improved performance are not. Using the principles of physics and biology, it is not possible for these wristbands to work. Add to that the study from RMIT University and it’s easy to see that performance is better improved through training and diet than through some mysterious Mylar disk.

Reference:

Brice SR, Jaroz BS, Ames RA, Baglin J, Da Costa C (2011) The effect of close proximity holographic wristbands on human balance and limits of stability: A randomized, placebo-controlled trial. Journal of Bodywork and Movement Therapies. DOI: 10.1016/j.jbmt.2011.01.020

Hall H, Power Balance products: A skeptical look. Device Watch. Downloaded, February 17, 2011. http://www.devicewatch.org/reports/power_balance.shtml

Power Balance Wristbands, http://www.powerbalance.com/austrailia/ca