Last modified: Friday, June 4, 2010
IU research at the American College of Sports Medicine annual meeting
Editors: More than 30 researchers from Indiana University participated in the annual meeting of the American College of Sports Medicine in Baltimore, June 2-5. Below is a sample of some of the research.
FOR IMMEDIATE RELEASE
June 4, 2010
Hip exercises reduce, eliminate common knee pain in runners
Dwelling interiors influence physical activity levels in middle aged African Americans
Stronger breathing muscles might leave more oxygen for other muscles during endurance sports
Making physical activity a vital sign to check during doctor visits
Compression clothes -- functional or fad?
Hip exercises found effective at reducing, eliminating common knee pain in runners. A twice weekly hip strengthening regimen performed for six weeks proved surprisingly effective at reducing -- and in some cases eliminating -- knee pain referred to as patellofemoral pain (PFP) in female runners. The study by Tracy Dierks, assistant professor in the Department of Physical Therapy at Indiana University-Purdue University Indianapolis, was based on the theory that stronger hips would correct running form errors that contribute to PFP, even though study participants were given no instruction in gait training. The study used a pain scale of 0 to 10, with 3 representing the onset of pain and 7 representing very strong pain -- the point at which the runners normally stop running because the pain is too great. The injured runners began the six-week trial registering pain of 7 when they ran on a treadmill and finished the study period registering pain levels of 2 or lower; i.e. no onset of pain. "I wasn't expecting such huge reductions, to be honest," Dierks said. "We've had a couple of runners who have been at level 2, but the overwhelming majority have been a 2 or below."
About PFP and the study:
- PFP, one of the most common running injuries, is caused when the thigh bone rubs against the back of the knee cap. Runners with PFP typically do not feel pain when they begin running, but once the pain begins, it gets increasingly worse. Once they stop running, the pain goes away almost immediately. Dierks said studies indicate PFP essentially wears away cartilage and can have the same effect as osteoarthritis. His study participants showed many of the classic signs of PFP, the most prominent being their knees collapsing inward when running or doing a squat exercise move.
- The pilot study thus far involved five runners and a control group that comprised another four runners. Hip strength measurements were taken before and after the runners in the control group maintained their normal running schedule for six weeks. Hip strength measurements were taken for all of the runners before and after the next six-week period in which they all performed the hip-strengthening exercises. The exercises, performed twice a week for around 30 to 45 minutes, involved single-leg squats and exercises with a resistance band, all exercises that can be performed at home. This study is part of an ongoing study involving hip exercises and PFP pain, with 11 runners successfully using the intervention. Dierks said he plans to seek funding to test the exercises on a larger group of runners.
- Earlier research had focused on the feet as a possible root of PFP, with studies only recently looking more closely at the hips. Dierks said studies have found an association between PFP in women and weak hips, but his study is the first to test a possible treatment. He noted that PFP is considered "multi-factorial," so his study is examining one of several possible causes of the pain.
Dierks will present the findings of his study, "The effect of hip muscle strengthening on pain when running in females with patellofemoral pain," on Friday, June 4, at 4:15 p.m. during the gait analysis II session. Co-investigators are Zachary H. Gergory, Rebecca L. Phipps and Peter A. Altenburger, all of IUPUI.
Tidy house, fitter body? An Indiana University study that examined the relationship between physical activity and a range of variables involving urban residents' homes and neighborhoods found that the inside of study subjects' homes had more to do with higher physical activity levels than the sidewalks, lighting and other elements considered. "At the end of the day, the interior condition of their house seemed to be the only thing affecting their physical activity," said NiCole Keith, associate professor in the Department of Physical Education at Indiana University-Purdue University Indianapolis. "It was not at all what we expected." The study involved 998 African Americans ages 49-65 who lived in St. Louis and participated in the African American Health longitudinal study, which began in 2000. African Americans, notes Keith, are disproportionally affected by risk factors for cardiovascular disease. Physical activity can reduce the likelihood that people will develop risk factors for cardiovascular disease and also reduce the effect of the risk factors when they exist. African Americans, however, have relatively low rates of physical activity. Keith said efforts to increase physical activity rates in city-dwellers might need to be taken inside. Much attention has been given to improving sidewalks and other aspects of the built environment outside, which Keith said is worthwhile, but if people already are active in their homes, researchers should look at ways to increase this. "If you spend your day dusting, cleaning, doing laundry, you're active," she said. "This will inform interventions. They won't take 30 minutes to go for a walk, but they'll take 30 minutes to clean."
More about the study:
- The study used a combination of self-assessments and objective assessments to gauge study participants' perceptions of their neighborhood and residences. Researchers based in St. Louis rated the interior and exterior of the dwellings and immediate vicinity, including such things as cleanliness, furnishings, noise, air quality and conditions of the dwelling and those of nearby buildings.
- The seasonally adjusted Yale Physical Activity Scale was used to assess physical activity. The YPAS was adjusted to take into consideration the self-assessments and object assessments along with demographic, socioeconomic, health conditions and physical measures involving subjects.
Keith said the findings were unexpected and raise more questions. They suggest that something about the condition of someone's residence drives physical activity, she said, or that people are being physically active while they keep their homes tidy. "Are the types of people who take care of their bodies the same types of people who take care of their homes?" she asked.
Keith is presenting her findings on Wednesday from 11 a.m.-12:30 p.m. in Hall C during the Environment, Policy and Physical Activity session. Co-authors of the study are Daniel O. Clark, IU Center for Aging Research and the Regenstrief Institute; Douglas K. Miller, M.D., IU Center for Aging Research,the Regenstrief Institute, and director of the African American Health Project.
Inspiratory muscle training and endurance sports. An Indiana University study found that strengthening inspiratory muscles by performing daily breathing exercises for six weeks significantly reduced the amount of oxygen these same breathing muscles required during exercise, possibly making more oxygen available for other muscles. Louise Turner, a researcher in the Department of Kinesiology, said just the act of breathing during an endurance activity, such as running, swimming or cycling performed at maximum intensity, can account for 10 to 15 percent of an athlete's total oxygen consumption. While inspiratory muscle training (IMT) has been shown to improve performance in endurance sports, Turner's study sought to shed light on how IMT does this. "This study helps to provide further insight into the potential mechanisms responsible for the improved whole-body endurance performance previously reported following IMT," she said.
About the study:
- The double blind, placebo-controlled study involved 16 male cyclists ages 18 to 40.
- IMT involves the use of a hand-held device that provides resistance as one inhales through it, requiring greater use of inspiratory muscles. For half of the study participants, the IMT device was set to a level that provided resistance as the subjects took a fast forceful breath in. For six weeks they took 30 breaths at this setting twice a day. The cyclists in the control group did the same exercises with the IMT adjusted to a minimal level.
- After six weeks, when the study participants mimicked the breathing required for low, moderate and maximum intensity activities, the inspiratory muscles required around 1 percent less oxygen during the low intensity exercise and required 3 to 4 percent less during the high intensity exercise.
Muscles need oxygen to produce energy. Turner's research also is looking at the next component of this equation, whether more oxygen is actually available to other muscles, particularly those in the legs, because less oxygen is being used by the breathing muscles. IMT has been used as an intervention in pulmonary diseases and conditions, such as asthma, COPD and cystic fibrosis, and also is marketed as a means for improving athletic performance in cyclists, runners and swimmers.
Turner is presenting her study, "Inspiratory Muscle Training reduces the Oxygen Cost of Breathing during Exercise," on Thursday, June 03, from 9-10:30 a.m. in Hall C. Co-authors are Timothy D. Mickleborough, Joel M. Stager and Robert F. Chapman from Indiana University; and Sandy Tecklenburg-Lund, Nebraska Wesleyan University.
A doctor's referral for better fitness. People visit physicians to get or stay healthy, but should questions about physical activity be a part of these visits, too -- every time? The American College of Sports Medicine and its Exercise is Medicine program think so. So does Indiana University physical activity expert NiCole Keith. "Doctors ask their patients about cigarette smoking, alcohol consumption and dietary habits, because those behaviors habits all affect health," said Keith, associate professor in the Department of Physical Education at Indiana University-Purdue University Indianapolis. "Failure to exercise or be physically active also is linked to several chronic diseases, and a discussion about those habits also must be part of a general medical visit. One of the goals of Exercise is Medicine is for physicians to consider physical activity levels a vital sign that should be checked during office visits, similar to height, weight, blood pressure and other vital signs. If health care providers take just one minute, Keith said, to ask about physical activity levels and counsel patients, if necessary, they could then refer them to an appropriate program in the community or healthcare system for additional help. "Hearing from a provider that you need to be more physically active or need to exercise will reduce the stigma associated with exercise and physical activity," said Keith.
Keith was invited to discuss her research on this topic at a special workshop during the American College of Sports Medicine's annual meeting. "The extension of Exercise is Medicine Model: Clinical Interventions for Promoting Physical Activity and Reducing Health Disparities in Medically Underserved Populations," will take place on Wednesday from 3:15-4:05 p.m. in Holiday Ballroom 4. Also speaking will be John Duperly, professor at the Universidad del Rosario School of Medicine in Columbia.
- Keith said physicians are reluctant to prescribe exercise for many reasons, including a general lack of training in exercise, uncertainty about how receptive patients will be to the suggestions, a reluctance to add to the patients' health care 'to do' lists, and the pragmatic fact that they can't bill for the counseling. She notes, however, that physicians frequently refer patients to specialists when the physicians lack the necessary expertise. She also said many fitness experts are interested in seeing physical activity screenings added to HEDIS guidelines. HEDIS stands for Healthcare Effectiveness Data and Information Set, a standardized set of performance measures developed by the National Committee for Quality Assurance to evaluate consumer health care.
- Keith will discuss findings from her research involving Take Charge Lite (TCL), a weight management program offered at an urban community health center in Indianapolis that primarily serves low-income and disadvantaged populations. Participants are referred to the program by their doctors. Keith will discuss referral rates and outcomes of the 4-year-old program. She and her colleagues are finding that the more contact participants have with the program, the more successful they are at losing weight. When patients contact the program once a month, they maintain their weight, rather than losing or gaining weight, Keith said. When they have six or more contacts, which can include exercising, getting weighed, attending a group meeting or other activities, they lose weight. She also will discuss what she and her colleagues have learned about people who are eligible for TCL but choose not to participate.
- Keith will discuss the need to identify community resources that underserved populations might use to become physically active. In addition to TCL, patients who want to workout at a gym are referred to PARCS Fit for Life, a collaborative effort involving IUPUI, ACSM, the Indianapolis Public Schools and the Indianapolis Housing Agency. The Physically Active Residential Communities and Schools (PARCS) partnership brings exercise and other opportunities for physical activity and health promotion to public housing communities and to high school fitness centers where students, staff and community members exercise. Keith said these underserved individuals represent some of greatest health disparate groups; these groups can't typically afford health clubs and have little knowledge about what it means to become and stay physically fit.
Study shows that calf compression does not improve running mechanics or running economy. The Indiana University study "Lower Leg Compression Sleeves: Influence on Running Mechanics and Economy in Highly Trained Distance Runners" found that lower leg compression garments did not impact a runner's oxygen consumption, which meant there was no change in running economy or efficiency. The study also found that calf compression garments did not have an effect on running mechanics. Abigail Laymon, researcher in the Department of Kinesiology, examined the impact a lower leg compression garment -- basically, a more compressive tall sock that begins just above the ankle and goes a little below the knee -- had on a runner's running mechanics and running economy. Lower leg compression garments have gained popularity in the professional field of distance running, despite a lack of solid research supporting their use. "Distance runners may try them out initially, because they see other runners using them with success," Laymon said. "Since some runners are somewhat superstitious, they may continue to use them if they happen to have a good race and attribute it to the compression."
About the study:
- Sixteen highly trained male distance runners were the subjects of this study. Each subject had to complete two 12-minute running tests -- one with lower leg compression and one without. During each test, the subjects had to run at three speeds: a 6.55 minute per mile pace, a 6 minute per mile pace, and a 5.21 per mile pace. During the tests, the runners spent four minutes at each speed.
- Running economy is the amount of energy one expends on a given workload. Mechanics and economy are linked -- the more unnecessary motion that is exerted while running will usually result in a greater waste of energy resulting in a worse economy. To study a runner's economy, Laymon measured the runner's oxygen consumption at three different running speeds. Lower oxygen consumption indicated better economy. The subjects ran at each speed with and without lower leg compression. However, the study found that the runners' economy did not change when wearing the garment.
- The runners' mechanics were not affected as well. Laymon found no differences in ground contact time, stride length or stride frequency. "Highly trained runners have an ingrained running style, so changing it is difficult," Laymon said. "Typically they have already selected the best running style for themselves. An intervention like compression may not affect them, especially a commercially available grade of compression that is slightly more compressive than a sock."
Although overall the study found that the compression garment had no effect on running mechanics and economy, there was some variation. Four subjects had an average of greater than one percent increase in oxygen consumption -- their economy worsened -- while wearing the compression garment. However, four other subjects experienced a greater than one percent decrease in oxygen consumption -- their economy improved -- while wearing the compression garment. Laymon had her subjects complete a subjective questionnaire about their feelings toward compression garments before completing their tests. It turned out that the subjects who experienced improvement in their economy were more likely to have a favorable attitude toward compressive wear and believed that by wearing the compressive garment their racing would improve. "Overall, with these compressive sleeves and the level of compression that they exert, they don't seem to really do much," Laymon said. "However, there may be a psychological component to compression's effects. Maybe if you have this positive feeling about it and you like them then it may work for you. It is a very individual response."
The study, "Lower Leg Compression Sleeves: Influence on Running Mechanics and Economy in Highly Trained Distance Runners" will be presented on Wednesday, June 2, during the Human Performance I session. Co-authors include Robert F. Chapman, Joel M. Stager, S. Lee Hong and Jeanne D. Johnston, all faculty members in the Department of Kinesiology in IU's School of Health, Physical Education and Recreation.
Study shows that compression garments do not improve one's level of performance. An Indiana University study, "Limb Compression Does Not Alter Jump Height Variability During The Vertical Jump," found that compression garments -- compressing specifically the upper thigh -- did not improve one's jump height during the vertical jump. Many compression garments come with manufacture claims that their product will increase a consumer's performance. "I didn't buy into that," said Nathan Eckert, a human performance doctoral student at Indiana University and lead researcher of this study. "To think there is something you can just put on and immediately you are better at what you do, just seemed too good to be true." The vertical jump was used in the study, because it is an assessment that correlates to other anaerobic measures such as sprints. If someone wears a compressive short while performing a vertical jump and they don't jump any higher, then that suggests that they will not perform better in other anaerobic events, Eckert said. Eckert said that he hopes from this study, consumers will be weary before they purchase a compression garment based off a company's manufacture claims. "Consumers need to keep in mind that this is a business, and that they are trying to sell you their product," Eckert said. However, consumers are not the only ones that believe these claims of performance improvement. Swimming's governing body, Federation Internationale De Natation, has banned full body compression swimsuits from being worn by male swimmers in the 2012 Olympics.
More about the study:
- The study involved 25 males who were around the age of 23 years old and weighed between 160 to 190 pounds. The subjects completed vertical jumps while wearing a compression garment that covers a person from their waist to the knee. Participants had to wear three different levels of compression: one made to fit the individual, one that was a size smaller and one that was a size larger.
- The study examined if there was a difference in the height of the participants' vertical jumps depending on the level of compression a participant was wearing. Participants had to wear each of the three different levels of compression and they performed the vertical jump while wearing each one. Their vertical jumps were then measured to see if their performance had changed in any way. "We looked at various different angles to see if the variability changed and nothing significant happened," Eckert said. "This basically states that at all three different levels of compression did absolutely nothing for them."
The study "Limb Compression Does Not Alter Jump Height Variability During The Vertical Jump," is being presented during the D-34-Neural Control of Movement and Balance session on Thursday, June 3. Co-authors include David Koceja, Timothy Mickleborough and Joel Stager, faculty members in the Department of Kinesiology in IU's School of Health, Physical Education and Receation.
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