Ankle flexibility study by Indiana State prof shows benefits last several weeks

March 1 2006

A study conducted by an Indiana State University professor shows ankle flexibility can be maintained without continuing vigorous exercises or the use of deep shortwave heating.

Jody Brucker, an assistant professor in ISU's department of Athletic Training, conducted the study with other key researchers in Provo, Utah.

The results of the study - "An 18-Day Stretching Regimen, With or Without Pulsed, Shortwave Diathermy, and Ankle Dorsiflexion After 3 Weeks" - were published in the winter 2005 issue of The Journal of Athletic Training, a quarterly, scientific publication from the National Athletic Trainers' Association.

The study examined the retention of ankle flexibility with 23 healthy, college-aged males or females. The participants were divided into two groups - one that stretched every day; and one that received shortwave diathermy, an instrument that heats deep tissue before and during stretching every day.

The stretching program lasted for 18 days with weekends off. Thereafter, the students returned after three weeks and were measured to see if there was a decrease in range of motion in their ankles.

The results of the study show flexibility of the ankle can be maintained even after a three-week period, without stretching.

Mack Rubley, graduate coordinator in the University of Nevada Las Vegas's department of Kinesiology, who helped with this research, said the study impacts everyday people and athletic trainers.

"For the general person, it may be that without regular stretching, we don't return to our 'inflexible' state quite as fast as we think," Rubley said. For athletic trainers, he said, this study will save time and money by not using therapeutic methods when stretching healthy people.

Brucker said this study also allows trainers to rest easy knowing their treatment with a patient will not go wasted as long as the patient stays active.

Another important finding is that adding shortwave diathermy to heat the targeted tissue does not increase flexibility or increase the time a person remains flexible.

"If you add this diathermy to this stretching regime, does it help you retain it? Does it help a person maintain the gains of range of motion?" Brucker said. "It didn't."

Another study showed that the use of shortwave diathermy helped the ankle gain range of motion and maintain it for seven days, over stretching alone. Brucker's study shows that this is still questionable.

Rubley points out that this study involved healthy, uninjured participants.

"We may see very different results with an injured population, like those returning from an Achilles injury," Rubley said. "Therefore, we need to be very cautious about saying diathermy is ineffective. It just does not appear to be of greater benefit than stretching alone when combined with stretching of uninjured healthy subjects."

Though the study found flexibility was maintained without rigorous stretching, the range of motion may naturally decrease over a longer period of time, but this has yet to be tested.

Brucker said, "Going based on the theory that trained effects will eventually be lost without some form of maintenance, I think the reason that these subjects were able to maintain what they gained was that they may have enjoyed the new range of motion."

Brucker said he saw a need for this study while working with patients to gain range of motion.

"What really motivated us was that we really want to know, if someone was treated, would it be maintained, or do they need to be continually treated?" he said.

There is still more to be learned on this subject, Brucker said.

"To extend this further, we'd have to have a much larger body of subjects and track them over a longer period of time," he said.

Rubley also said it would be important to study injured participants to further test the theory against shortwave diathermy.

Brucker earned his athletic therapy diploma from Mount Royal College in Calgary, Canada, before completing his bachelor's degree from Fort Hays State University in Kansas, and becoming a certified athletic trainer. His master's degree is from Ohio University; and he graduated with a Ph.D. in exercise science, specializing in physical medicine and rehabilitation, from Brigham Young University in Utah.


Contact/Interview: Jody Brucker, assistant professor of athletic training, Indiana State University, (812) 237-3962

Writer: Megan Anderson, ISU Communications & Marketing student intern, Indiana State University

Media Relations Contact: Katie Spanuello, media relations assistant director, Indiana State University, (812) 237-3790 or

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A study conducted by Indiana State University professor Jody Brucker shows ankle flexibility can be maintained without continuing vigorous exercises or the use of deep shortwave heating.

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