Consuming energy drinks during team sports could help young people perform better, a study suggests. Sports scientists found that 12-14 year olds can play for longer in team games when they drink an isotonic sports drink before and during games. Researchers at the University of Edinburgh measured the performance of 15 adolescents during exercise designed to simulate the physical demands of team games such as football, rugby and hockey.
They showed for the first time that sports drinks helped the young people continue high intensity, stop-start activity for up to 24 per cent longer -- compared with players who drank a non-carbohydrate placebo solution.
The study was conducted because there is increasing evidence of young people consuming commercially available energy drinks during team games and researchers wanted to assess their impact. The findings are published in the European Journal of Applied Physiology.
The findings showed that drinking a 6 per cent carbohydrate-electrolyte solution improved endurance capacity but did not make young people run faster during intermittent exercise in team sports. The solution -- containing carbohydrate, sodium, potassium, magnesium and calcium -- enhances hydration, helps prevent dehydration and provides a supply of energy to the body, thereby contributing to improved endurance capacity.
The researchers say the findings help to identify the importance of regular hydration and energy intake with a carbohydrate-electrolyte solution during games to replace fluids and provide energy in adolescent games players.
Dr John Sproule, Head of the Institute of Sport, Physical Education and Health Sciences of the University of Edinburgh's Moray House School of Education who led the research, said: "The importance of hydration to improve performance during exercise for adults is well known. This research helps us further understand how adolescents respond to hydration and energy supply during exercise. The consumption of a carbohydrate-electrolyte solution was found to significantly enhance endurance capacity during simulated games play, and this could contribute to improved performance in adolescents."
Researchers say that this is the first study to explore the effect of a 6 per cent carbohydrate-electrolyte solution, similar to the make-up of an isotonic sports drink, on the performance of young people in team games.
Anterior cruciate ligament injuries are a common and debilitating problem, especially for female athletes. A new study from UC Davis shows that changes in training can reduce shear forces on knee joints and could help cut the risk of developing ACL tears.
"We focused on an easy intervention, and we were amazed that we could reduce shear load in 100 percent of the volunteers," said David Hawkins, professor of neurobiology, physiology and behavior at UC Davis. Hawkins conducted the study at the UC Davis Human Performance Laboratory with graduate student Casey Myers.
The anterior cruciate ligament lies in the middle of the knee and provides stability to the joint. Most ACL injuries do not involve a collision between players or a noticeably bad landing, said Sandy Simpson, UC Davis women's basketball coach.
"It almost always happens coming down from a rebound, catching a pass or on a jump-stop lay-up," Simpson said. "It doesn't have to be a big jump."
Hawkins and Myers worked with 14 female basketball players from UC Davis and local high schools. They fitted them with instruments and used digital cameras to measure their movements and muscle activity, and calculated the forces acting on their knee joints as they practiced a jump-stop movement, similar to a basketball drill.
First, they recorded the athletes making their normal movement. Then they instructed them in a modified technique: Jumping higher to land more steeply; landing on their toes; and bending their knees more deeply before taking off again.
After learning the new technique, all 14 volunteers were able to reduce the force passed up to the knee joint through the leg bone (the tibial shear force) by an average of 56 percent. At the same time, the athletes in the study actually jumped an inch higher than before, without losing speed.
Hawkins recommends warm-ups that exercise the knee and focusing on landing on the toes and balls of the feet. The study does not definitively prove that these techniques will reduce ACL injuries, Hawkins said: that would require a full clinical trial and follow-up. But the anecdotal evidence suggests that high tibial shear forces are associated with blown knees.
Hawkins and Myers shared their findings with Simpson and other UC Davis women's basketball and soccer coaches, as well as with local youth soccer coaches. The research was published online Aug. 3 in the Journal of Biomechanics.
Simpson said that the team had tried implementing some changes during last year's preseason, but had found it difficult to continue the focus once the full regular season began. In live play, athletes quickly slip back to learned habits and "muscle memory" takes over, he noted. More intensive off-court training and practice would be needed to change those habits, he said.
"We will be talking about this again this season," Simpson said. Implementing the techniques in youth leagues, while children are still learning how to move, might have the most impact, he said.
Congratulations, you actually made it to the finish line after 26.2 miles of agony. You are exhausted and need some kind of recovery drink to pick you back up. Reach for the Gatorade? Chocolate milk? Water? No, your best bet is a big glass of tart cherry juice!
Dr Glyn Howatson, exercise physiologist and Laboratory Director in the School of Psychology and Sports Sciences at Northumbria University, examined the properties of Montmorency cherries in a study that found that athletes who drank the juice recovered faster after Marathon running than a placebo controlled group.
In the investigation, 20 marathon runners drank either a tart cherry blend juice or a placebo drink twice a day for five days before taking part in the London Marathon and for two days afterwards.
The findings indicated that the group who drank the cherry juice recovered their strength more rapidly than the control group over the 48-hour period following the marathon. Inflammation was also reduced in the cherry juice group, as was oxidative stress, a potentially damaging response that can be caused by strenuous physical activity, particularly long distance endurance exercise.
The study, which was run in collaboration with PhD student Jess Hill of St Mary's University College, concluded that cherry juice appears to aid recovery following strenuous exercise by increasing total antioxidative capacity, reducing inflammation and oxidative stress, hence aiding in the recovery of muscle function.
Dr Glyn Howatson(Credit: Image courtesy of Northumbria University)
Dr Howatson said: "Participating in long-distance endurance events, such as the London Marathon, causes a degree of muscle damage and inflammation for the runners. It takes several days to recover and during that period the runner's ability to conduct physical activity can be vastly inhibited.
"The phytochemicals, in particular, anthocyanins found in Montmorency cherries have anti-inflammatory and antioxidating properties, which the research has shown to be effective in helping exercisers to recover from strenuous physical activity."
Although it remains to be examined, Dr Howatson believes that the findings will not only benefit marathon runners but could also have serious implications in the treatment of people living with inflammatory diseases, such as arthritis.
He said: "If funding can be secured to embark on a further study, we can determine whether the use of tart cherry juice has implications for the management of some clinical pathologies that display high levels of inflammation and oxidative stress, such as rheumatoid arthritis and fibromyalgia.
"People are increasingly looking at natural remedies, or neutraceuticals, to treat their conditions, and scientific studies, such as the research into tart cherries, examine the potentially untapped treatments held in natural resources, that can provide adjunct therapy for the management of disease, which can help reduce negative symptoms and improve quality of life."
Source: Northumbria University and Howatson et al. Influence of tart cherry juice on indices of recovery following marathon running. Scandinavian Journal of Medicine and Science in Sports, 2009; DOI: 10.1111/j.1600-0838.2009.01005.x
Highly fit multiple sclerosis patients perform significantly better on tests of cognitive function than similar less-fit patients, a new study shows. In addition, MRI scans of the patients showed that the fitter MS patients showed less damage in parts of the brain that show deterioration as a result of MS, as well as a greater volume of vital gray matter.
"We found that aerobic fitness has a protective effect on parts of the brain that are most affected by multiple sclerosis," said Ruchika Shaurya Prakash, lead author of the study and assistant professor of psychology at Ohio State University. "As a result, these fitter patients actually show better performance on tasks that measure processing speed."
The study, done with colleagues Robert Motl and Arthur Kramer of the University of Illinois and Erin Snook of the University of Massachusetts, Amherst, appears online in the journal Brain Research and will be published in a future print edition.
The study involved 21 women diagnosed with relapsing-remitting MS. They were compared with 15 age- and education-matched healthy female controls. The study assessed fitness, cognitive function, and structural changes in all participants. In order to measure fitness levels, the participants underwent a VO2 max test, in which they rode a stationary bicycle until they felt exhausted. During the test, they breathed into a mask which measured their oxygen consumption.
All the women also took a variety of tests designed to evaluate cognitive functions, such as processing speed and selective attention. In one test, for example, participants had to write down in one minute as many words as they could think of that began with the letter "F." MS patients generally perform poorly on these tests compared to healthy people. The third analysis involved MRIs of the participants, revealing any damage to their brains.
As expected, the MS patients did much worse than the healthy controls on the tests of brain functioning, and showed more deterioration in their brains as revealed through the MRIs. But what was interesting, Prakash said, was the significant differences between the more aerobically fit MS patients and those who were less fit.
Take, for instance, lesions, which are the characteristic feature of MS. Lesions are areas of inflammation in the central nervous system in which neurons have been stripped of myelin, an insulating protein.
"Physically fit MS patients had fewer lesions compared to those who weren't as fit and the lesions they did have tended to be smaller," Prakash said. "This is significant and can help explain why the higher-fit patients did better on tests of brain functioning."
Aerobic fitness was also associated with less-damaged brain tissue in MS patients, both the gray matter and white matter. Gray matter is the cell bodies in the brain tissue, while white matter is the fibers that connect the various gray matter areas.
The study found that fitness in MS patients was associated with larger volume of gray matter, accounting for about 20 percent of the volume in gray matter. That's important, Prakash said, because gray matter is linked to brain processing skills.
"Even in gray matter that appeared relatively healthy, we found a deterioration in the volume in MS patients," she said. "But for some of the highest fit MS patients, we found that their gray matter volume was nearly equivalent to that of healthy controls."
Another MRI analysis involved the integrity of the white matter in the brain. In MS patients, the white matter deteriorates as the myelin is stripped from neurons. Again, higher-fit MS patients showed less deterioration of white matter compared to those who were less fit.
Overall, the three MRI tests in this study showed that parts of the brain involved in processing speed are all negatively affected by MS -- but less so in patients who are aerobically fit.
Prakash noted that other researchers have found that exercise promotes the production of nerve growth factors, proteins which are important for the growth and maintenance of neurs in the brain. "Our hypothesis is that aerobic exercise enhances these nerve growth factors in MS patients, which increases the volume of the gray matter and increases the integrity of the white matter," she said. "As a result there is an improvement in cognitive function."
Prakash and her colleagues plan to extend this research by studying whether exercise interventions with MS patients can actually improve their cognition and have positive physical effects on the brain.
"For a long time, MS patients were told not to exercise because there was a fear it could exacerbate their symptoms," she said. "But we're finding that if MS patients exercise in a controlled setting, it can actually help them with their cognitive function."
The research was supported by a grant from the National Institute on Aging.
Olympic skeleton athletes will hit the ice this week in Vancouver, where one-hundredths of a second can dictate the difference between victory and defeat. Using state-of-the-art flow measurements, engineering professor Timothy Wei and students at Rensselaer Polytechnic Institute in Troy, N.Y., are employing science and technology to help the U.S. skeleton team trim track times and gain an edge over other sliders.
"Not much is known about the actual mechanics of skeleton, so we developed a unique suite of tools to help pull back the curtain a bit," said Wei, head of Rensselaer's Department of Mechanical, Aerospace, and Nuclear Engineering, who has previously worked with U.S. Olympic swimming coaches and athletes. "Even in the short time since developing the system, we have learned a whole lot more about how the athlete's suit, helmet, body movements, and positioning affect aerodynamics."
"The real-time aerodynamics work that Rensselaer has provided for us has helped to fine-tune our athletes' body positions and equipment in a way that we've never experienced before," said USA Skeleton Technology Coordinator Steve Peters. "These new concepts will give our athletes the data they need to remain competitive with the rest of the world."
Lying face-down, and hitting speeds of more than 70 mph (112 kph), skeleton athletes maneuver their sleds down an icy, mostly-covered track rife with twists and turns. Skeleton sleds feature no steering or braking mechanisms, so body control and balance are critical for navigating the tracks. A relatively young sport, skeleton was permanently added to the Olympic program in 2002. Skeleton is rigorous on an athlete's body -- the vibrations and bodily stress are so intense that even Olympic contenders usually cannot slide more than four times per day, making it difficult to collect data.
So Wei set out to build a system that accurately simulated an actual skeleton run, while collecting as much data as possible. The professor understood that the more drag, or wind resistance, an athlete creates, the slower he or she is going to slide, so Wei needed to find a way to examine all the different variables: the clothing, headgear, and body position of sliders, as well as the skeleton sled itself. Studying drag requires wind, and the skeleton sled was slightly too large to fit into either of Rensselaer's two wind tunnels. The jet of air exiting the exhaust vent of the wind tunnel, however, worked perfectly.
Wei and his students created a replica section of a skeleton track directly behind the wind tunnel. They built sensors into the floor of the replica, onto which they placed a skeleton sled. Each sensor was fit with an oscilloscope, and sent digital data to a nearby computer that calculated the sled's pitch, roll, and balance -- technical terms for indicating if the slider is leaning backward, forward, left, or right. The sensors also measured wind resistance, or drag.
With a skeleton athlete lying on a sled in the test track, Wei turned on the wind tunnel. The steady stream of air exiting the wind tunnel's exhaust replicated the conditions of an actual skeleton run. Wei and his team cut a hole in the bottom of the test track, slid in a computer monitor, and covered the hole with clear plastic. This allowed the athletes to view, in real time, data and graphs clearly illustrating the impact that every little lean or tilt had on wind resistance, and thus on their speed. One side wall of the track was also made from clear plastic, allowing coaches to observe the tests.
Wei and Peters brought 10 different skeleton athletes to Rensselaer for a test run on the new system. They tested a wide variety of skeleton suits and gear, some of which, Wei said, certainly created more drag than others. "This is more information than these athletes have ever had about the impact of what they're doing while sliding," Wei said. "It was a real eye-opener for them."
To further test the athletes, suits, and headgear, Wei also developed a state-of-the-art diagnostic tool using a video-based flow measurement technique known as Digital Particle Image Velocimetry (DPIV). He bounced a green pulse laser off a cylindrical lens to create a thin sheet of light, which he shined over the shoulders of athletes laying the test system. Wei then introduced theatrical fog into the front of the test bed.
Wei videotaped the fog as it was pushed around by the wind tunnel exhaust, and then used sophisticated mathematics, computer modeling, and stop-motion video to track the behavior of the swirly fog as it rolled off the bodies and heads of the athletes. This data, he said, can be used to identify vortices, pinpoint the movement of air, and hopefully identify new and more detailed methods for skeleton athletes to reduce their drag.
Meanwhile, a team of undergraduate students in the O.T. Swanson Multidisciplinary Design Lab (MDL) at Rensselaer looked at different engineering techniques to help improve the skeleton sleds. They developed a data acquisition system for the sleds, which measured specific mechanical properties of the sled in real-time as the athlete guided it down the track. One component of this system is a camera that attaches to the slider's helmet, providing athletes and coaches with a new proof-of-concept tool from which to learn.
Wei is no stranger to applying science and technology to the world of sports. He has been working with USA Swimming for several years, using DPIV and other techniques to better understand how swimmers interact with the water. He also created a robust training tool that reports the performance of a swimmer in real-time, measuring how much energy the swimmer exerts with each kick. The tool helped several top-tier athletes trim seconds from their lap times.
Wei said he's confident that the United States will have a strong showing in skeleton in Vancouver, and that he's looking at ways to improve his technology to be even more effective when training swimmers to compete in the 2012 London Olympics and skeleton athletes to compete in the 2014 Winter Olympics in Sochi, Russia.
Switzerland has a long tradition of bobsledding and the Swiss Bobsleigh Federation has a remarkable record at international competitions. Currently, Switzerland even boasts two reigning world champions: Ivo Rüegg in the two-man bob and junior world champion Sabina Hafner. Moreover, pilot Beat Hefti won last year’s world cup season – also in the two-man bob.
To be better than the rest, the athletes not only need talent and experience, but also a fast bobsled. No one knows this better than former bobsledder and leader of the “CITIUS” project, Christian Reich: “for a pilot, being able to rely on a strong team and fast equipment is the key to good performance.”
Consequently, three years ago a joint venture between the Swiss Bobsleigh Federation (SBSV), researchers from ETH Zurich and Swiss industrial companies set about building a high-speed bobsled from scratch. “We wanted to build a bobsled that was faster than the competition because in bobsledding you can’t afford to sit back”, explains Peter J. Schmid, Central President of the SBSV.
The project was named “CITIUS” after the motto of the Olympic Games, “Citius, altius, fortius” (faster, higher, stronger). Last Fall, after thousands of hours of development and numerous trials in the wind tunnel and on the ice track, the developers and federation representatives handed over the new high-tech sled to the Olympic bobsled squad in front of the media.
Eliminating brake sources
As far as ETH Zurich was concerned, about two dozen researchers from the Departments of Mechanical Engineering, Process Engineering and Materials Science were involved in the development of the bobsled. It was their job to refine the material whilst keeping to the specifications of the International Bobsleigh Federation and optimize the runners, aerodynamics, stability and vibrations.
Professor Ueli Suter, Program Coordinator at ETH Zurich, said that, “For a vehicle without an engine that hurtles down an ice track at 150 km/h, finding all the important brake sources, then eliminating them and still producing a safe piece of equipment for the athletes is a complex interdisciplinary undertaking.”
Extensive industrial expertise sought The results of the research conducted at ETH Zurich were passed on to project supervisor Christian Reich, who in turn passed them on to the development, training and production workshops of the specialist industrial companies (see box). Dr. Jürg Werner, the head of V-Zug AG’s development department, said, “The industrial partners involved contributed their expertise to the project because they feel an affinity to Swiss bobsledding. The collaboration with ETH Zurich and among industrial partners resulted in a welcome transfer of knowledge. CITIUS stands for innovation, as do the industrial partners involved.”
The countdown is on!
A total of six two-man bobsleds and three four-man bobsleds of the “CITIUS” model have been constructed and are ready to compete for hundredths of a second. The final test runs are scheduled for the second half of October in Cesana/Turin before the Swiss pilots are given their first and only opportunity to train with the new bobsleds on Whistler’s Olympic bobsled track. Shortly afterwards, the world cup season gets underway with the first race in Park City.
The bobsled competition at the Winter Olympics in Vancouver will be held from February 20 – 27 2010. By then at the latest, we should know whether the big efforts of all those involved in the “CITIUS” project have paid off and whether Switzerland can add to its medal collection as a bobsledding nation.
In this World Cup year, when football (soccer) passions are running high, supporters might be forgiven for objecting to every decision to award a foul against their team, made by referees. But they might also have a point. Researchers at Rotterdam School of Management, Erasmus University have researched all recorded fouls in three major football competitions over seven years. They discovered an ambiguous foul is more likely to be attributed to the taller of two players.
Dr. Niels van Quaquebeke and Dr. Steffen Giessner, scientists at Rotterdam School of Management, Erasmus University began their research by transferring their insights from decision making in business into the arena of sports. Specifically, they wanted to investigate whether people consider the available information in such ambiguous foul situations in an unbiased, i.e. subconsciously unprejudiced, way.
Based on evolutionary and linguistic research which has revealed that people associate the size of others with concepts such as aggression and dominance, Van Quaquebeke and Giessner speculated that ambiguous fouls are more likely to be attributed to the taller of two involved players. Results indicate that respectively taller people are more likely to be perceived by referees (and fans!) as foul perpetrators and their respectively smaller opponents as foul victims.
To put their assumption to a test, the scientists analysed all fouls recorded by Impire AG in seven seasons of UEFA Champions League (32,142 fouls) and German Bundesliga (85,262 fouls), the last three FIFA World Cups (6,440 fouls) as well as data from two additional perceptual experiments with football fans. For all seasons, leagues, and data collection methods, their analyses revealed the same picture confirming their initial assumption: taller people are indeed more often held accountable for fouls than shorter ones -- even when no actual foul was committed.
An article based on their research will be published in the Journal of Sport & Exercise Psychology in February 2010.
Van Quaquebeke said, "We chose football as the context of our studies because the sport often yields ambiguous foul situations in which it is difficult to determine the perpetrator. In such situations, people must rely on their 'instincts' to make a call, which should increase the use and thus the detectability of a player's height as an additional decision cue. Furthermore, the use of referee assistance technology and adequate referee training is frequently debated in association football. Thus, by providing scientific insights on potential biases in refereeing, our work might help officials weigh the options."
Both researchers say, however, that it is not their call how to derive conclusions for football practice.
The maximum time an athlete is able to continue climbing to exhaustion may be the only determinant of his/her performance. A new European study, led by researchers from the University of Granada, the objective of which is to help trainers and climbers design training programmes for this type of sport, shows this to be the case.
Until now, performance indicators for climbing have been low body fat percentage and grip strength. Furthermore, existing research was based on the comparison of amateur and expert climbers. Now, a new study carried out with 16 high-level climbers breaks with this approach and reveals that the time it takes for an athlete to become exhausted is the only indicator of his/her performance.
Vanesa España Romero was the first author of the work and is a researcher at the University of Granada.
The study, published in the European Journal of Applied Physiology, analyses the physiological parameters that determine performance in this sport at its highest level. The participants, eight women with an average rating of 7a (the scale of difficulty of a climbing route is graded from 5 to 9, with sub-grades of a, b and c) and eight men with an average rating of 8a, were divided into an "expert group" and an "elite group."
The researchers assessed the climbers with body composition tests (weight, height, body mass index, body fat %, bone mineral density, and bone mineral content), kinanthropometry (length of arms, hands and fingers, bone mineral density and bone mineral content of the forearm), and physical fitness tests (flexibility, strength of the upper and lower body and aerobic capacity measured at a climbing centre).
The results show there to be no significant differences between expert and elite climbers in any of the tests performed, except in climbing time to exhaustion and in bone mineral density, both of which were higher in the elite group. "Therefore, the maximum climbing time to exhaustion of an athlete is the sole determinant of performance," the researcher confirms.
Sport climbing began as a form of traditional climbing in the mid 80s, and is now a sport in its own right. The International Federation of Sport Climbing is currently requesting its inclusion as an Olympic sport.
The increase in the number of climbers and the proliferation of climbing centres and competitions have contributed to its interest in recent years, although there is limited scientific literature on climbing effort.
The most important research relates to energy consumption (ergospirometry, heart rate and lactic acid blood concentrations), the designation of maximum strength and local muscular resistance of climbers (dynamometry and electromyography), and to establishing anthropometric characteristics.
According to experts, a fundamental characteristic of sport climbing is its "vertical dimension," making it unique given its postural organisation in space, and from a physiological point of view, the effect a gravitational load has on movements.
In short, to complete a climb successfully, athletes should maintain their effort for as long as possible to improve their chances of reaching the ultimate goal.
While baseball fans still rank "The Catch" by Willie Mays in the 1954 World Series as one of the greatest baseball moments of all times, scientists see the feat as more of a puzzle: How does an outfielder get to the right place at the right time to catch a fly ball?
Thousands of fans (and hundreds of thousands of YouTube viewers) saw Mays turn his back on a fly ball, race to the center field fence and catch the ball over his shoulder, seemingly a precise prediction of a fly ball's path that led his team to victory. According to a recent article in the Journal of Vision ("Catching Flyballs in Virtual Reality: A Critical Test of the Outfielder Problem"), the "outfielder problem" represents the definitive question of visual-motor control. How does the brain use visual information to guide action?
To test three theories that might explain an outfielder's ability to catch a fly ball, researcher Philip Fink, PhD, from Massey University in New Zealand and Patrick Foo, PhD, from the University of North Carolina at Ashville programmed Brown University's virtual reality lab, the VENLab, to produce realistic balls and simulate catches. The team then lobbed virtual fly balls to a dozen experienced ball players.
"The three existing theories all predict the same thing: successful catches with very similar behavior," said Brown researcher William Warren, PhD. "We realized that we could pull them apart by using virtual reality to create physically impossible fly ball trajectories."
Warren said their results support the idea that the ball players do not necessarily predict a ball's landing point based on the first part of its flight, a theory described as trajectory prediction. "Rather than predicting the landing point, the fielder might continuously track the visual motion of the ball, letting it lead him to the right place at the right time," Warren said.
Because the researchers were able to use the virtual reality lab to perturb the balls' vertical motion in ways that would not happen in reality, they were able to isolate different characteristics of each theory. The subjects tended to adjust their forward-backward movements depending on the perceived elevation angle of the incoming ball, and separately move from side to side to keep the ball at a constant bearing, consistent with the theory of optical acceleration cancellation (OAC). The third theory, linear optical trajectory (LOT), predicted that the outfielder will run in a direction that makes the visual image of the ball appear to travel in a straight line, adjusting both forward-backward and side-to-side movements together.
Fink said these results focus on the visual information a ball player receives, and that future studies could bring in other variables, such as the effect of the batter's movements or sound.
"As a first step we chose to concentrate on what seemed likely to be the most important factor," Fink said. "Fielders might also use information such as the batter's swing or the sound of the bat hitting the ball to help guide their movements."
Knee osteoarthritis (OA) accounts for more disability in the elderly than any other disease. Running, although it has proven cardiovascular and other health benefits, can increase stresses on the joints of the leg. In a study published in the December 2009 issue of PM&R: The journal of injury, function and rehabilitation, researchers compared the effects on knee, hip and ankle joint motions of running barefoot versus running in modern running shoes. They concluded that running shoes exerted more stress on these joints compared to running barefoot or walking in high-heeled shoes.
Sixty-eight healthy young adult runners (37 women), who run in typical, currently available running shoes, were selected from the general population. None had any history of musculoskeletal injury and each ran at least 15 miles per week. A running shoe, selected for its neutral classification and design characteristics typical of most running footwear, was provided to all runners. Using a treadmill and a motion analysis system, each subject was observed running barefoot and with shoes. Data were collected at each runner's comfortable running pace after a warm-up period.
The researchers observed increased joint torques at the hip, knee and ankle with running shoes compared with running barefoot. Disproportionately large increases were observed in the hip internal rotation torque and in the knee flexion and knee varus torques. An average 54% increase in the hip internal rotation torque, a 36% increase in knee flexion torque, and a 38% increase in knee varus torque were measured when running in running shoes compared with barefoot.
These findings confirm that while the typical construction of modern-day running shoes provides good support and protection of the foot itself, one negative effect is the increased stress on each of the 3 lower extremity joints. These increases are likely caused in large part by an elevated heel and increased material under the medial arch, both characteristic of today's running shoes.
Writing in the article, lead author D. Casey Kerrigan, MD, JKM Technologies LLC, Charlottesville, VA, and co-investigators state, "Remarkably, the effect of running shoes on knee joint torques during running (36%-38% increase) that the authors observed here is even greater than the effect that was reported earlier of high-heeled shoes during walking (20%-26% increase). Considering that lower extremity joint loading is of a significantly greater magnitude during running than is experienced during walking, the current findings indeed represent substantial biomechanical changes."
Dr. Kerrigan concludes, "Reducing joint torques with footwear completely to that of barefoot running, while providing meaningful footwear functions, especially compliance, should be the goal of new footwear designs."
Source: Elsevier Health Sciences "The Effect of Running Shoes on Lower Extremity Joint Torques" by D. Casey Kerrigan, MD, Jason R. Franz, MS, Geoffrey S. Keenan, MD, Jay Dicharry, MPT, Ugo Della Croce, PhD, and Robert P. Wilder, MD. It appears in PM&R: The journal of injury, function and rehabilitation, Volume 1, Issue 12 (December 2009), published by Elsevier. The article has been made freely available and may be accessed at: http://www.pmrjournal.org/article/S1934-1482(09)01367-7/fulltext
Wow, what are the odds that I lead off this week's Gym Bag with a Tiger Woods story? Don't worry, this article has no mention of Escalades, golddiggers or mothers-in-law. Plus, plenty of other great stuff from the sports science world.
Success is intimidating. When we compete against someone who's supposed to be better than us, we start to get nervous, and then we start to worry, and then we start to make stupid mistakes. That, at least, is the lesson of a new working paper by Jennifer Brown, a professor at the Kellogg school.
Brown demonstrated this psychological flaw by analyzing data from every player in every PGA tournament from 1999 to 2006. The reason she chose golf is that Tiger Woods is an undisputed superstar, the most intimidating competitor in modern sports. (In 2007, Golf Digest noted that Woods finished with 19.62 points in the World Golf Ranking, more than twice as many as his closest rival. This meant that "he had enough points to be both No. 1 and No. 2.") Brown also notes that "golf is an excellent setting in which to examine tournament theory and superstars in rank-order events, since effort relates relatively directly to scores and performance measures are not confounded by team dynamics." In other words, every golfer golfs alone...
Vince Young
The underlying assumption of the Wonderlic test is that players who are better at math and logic problems will make better decisions in the pocket. At first glance, this seems like a reasonable conjecture. No other position in sports requires such extreme cognitive talents. A successful quarterback will need to memorize hundreds of offensive plays and dozens of different defensive formations. They'll need to spend hours studying game tape of their opponents so that, when they're on the field, they can put that knowledge to use. In many instances, quarterbacks are even responsible for changing the play at the line of scrimmage. They are like a coach with shoulder pads...
UN calls for football tax to fund education for poor children The United Nations today launches an appeal to FIFA football leagues, including the Premier League, to place a small levy on sponsorship revenues that would help get 2 million children in poor countries into school over the next five years...
Pushing Past the Pain of Exertion
LAST November, Kara Goucher ran the ING New York City Marathon, her first 26.2-mile race. Even though she was an Olympian who had placed 10th in the 10,000 meter race in 2008 in Beijing — running the equivalent of 6.2 miles — she felt fear. “I was really scared I wouldn’t be able to handle the pain for that long,” said Ms. Goucher, 31, who had never run more than 18 miles at a time before training for the marathon. “Now I was asking myself to run eight miles farther, a lot faster. It was daunting.”
Coaching and science: What's the big deal and who cares for the science?
"As promised, today begins a series of posts on coaching and science, and how the science can be, should be, and sometimes is, and often is not, applied to athlete preparation. Obviously, it comes with an endurance focus, but there's no reason why sprint coaches and team sport coaches can also not glean some information from this.
This is a series that was inspired by my visit to the US Olympic Center in Colorado Springs. I was lucky enough to be invited there by Prof Randy Wilber of the USOC, who had organized a symposium on altitude training. The symposium brought together scientists, coaches, athletes and mangers from 22 different countries, and included 32 Olympic athletes, and numerous sporting codes, Summer and Winter Olympics among them..."
Belichick had the numbers on his side Among the countless criticisms hurled at Patriots coach Bill Belichick for his decision to go for it on fourth down Sunday night, former Colts coach Tony Dungy summed up the most popular when, speaking on NBC, he said, “You have got to play the percentages and punt the ball.’’ What Dungy did not realize, though, is that “the percentages’’ dictated that Belichick do exactly what he did...
Short Heels and Long Toes: A Surprising Recipe for Speed
Track coaches have long claimed that the best sprinters are born, not made. Now, new research on the biomechanics of sprinting suggests that at least part of elite athletes’ impressive speed comes from the natural shape of their foot and ankle bones.
Using ultrasound imaging, researchers compared the feet of 12 top college sprinters with those of 12 mere mortals. Surprisingly, the athletes had particularly short heels and longer-than-average toes — features that actually put them at a mechanical disadvantage when running.
“What we found is that sprinters actually had less mechanical advantage than the non-sprinter subjects that we tested,” said biomechanics researcher Stephen Piazza of Penn State University, co-author of the study published Friday in the Journal of Experimental Biology. “This was surprising to us because we expected that sprinters needed all the help they could get.”
In an ironic twist, Oscar Pistorius' disability has now been shown to be an unfair advantage. The South African sprinter, who races with two prosthetic lower legs, has been the subject of a see-saw legal battle trying to determine if his carbon fiber, crescent-shaped manufactured legs give him an unfair advantage.
Now, two sports scientists have published new research showing that the legs, known as "Cheetahs," make him 15-20 percent faster, equal to 10 seconds over a 400 meter race, then he otherwise would be with natural legs.
In 2008, the Court of Arbitration for Sport (CAS) overturned a competition ban placed on Pistorius from the International Association of Athletics Federations (IAAF), track and field's governing body. Seven scientists produced research that refuted the IAAF's contentions and Pistorius was cleared in time to try for a spot on the Beijing Olympic squad. He just missed making that team by .7 seconds, but is now training for the 2012 London games. He did go on the win three gold medals in the 2008 Paralympics.
Pistorius, known as the Blade Runner, was born without fibula bones in his lower legs, resulting in a double amputation at the age of 11 months. At age 18, he won the 200m race at the 2004 Summer Paralympics, followed by a gold medal in the 2005 South African championships against able-bodied competitors.
Of course, when the discussion is about steroids, blood doping or even corked bats, the athlete becomes the villian. For the "fastest man on no legs," as Pistorius is often called, there are mixed opinions, ranging from those that champion the rights and progress of disabled athletes to those that want to preserve the perceived "level playing field" and integrity of the sport.
Supporting the CAS appeal, seven scientists showed that the IAAF's research (which held that Pistorius should not compete) was not valid. However, according to two of the scientists, Peter Weyand of Southern Methodist University in Dallas and Matthew Bundle of the University of Wyoming, they were careful not to imply that there was no advantage. "We are pleased to finally be able to go public with conclusions that the publishing process has required us to keep confidential until now. We recognized that the blades provide a major advantage as soon as we analyzed the critical data more than a year and a half ago," said Weyand and Bundle in a statement.
They explain that all of the group's research did not become public at the CAS hearing because, first, the CAS only asked them to refute the earlier research based on different logic and, second, the long timeline of the peer-review process of academic research just now made it possible to publish.
Specifically, what Weyand and Bundle found was that the lightweight blades weigh less than half of what a comparable human lower leg would, allowing Pistorius to swing his leg 15.7 percent faster than the average of five former 100m world record holders. They used high-speed motion cameras to compare leg speed and gait. "Even in comparison to those male sprinters with the most extreme adaptations for speed in recorded human history, Oscar Pistorius has limb repositioning times that are literally off the charts," Bundle said. "Usain Bolt is considered somewhat freakish because he outruns his opponents by 2-4 percent. At top speed, Oscar Pistorius repositions his limbs 15 percent more rapidly than six of the most recent world record holders in the 100 meter dash, including Usain Bolt."
In addition, because of how the Cheetahs, from Icelandic manufacturer Ossur, position his upper body, he can leave each "foot" on the ground longer, generating more force with each stride. "He repositions his limbs so fast that he doesn't need to get his body back up into the air so high like other sprinters, and that lowers the force he needs to generate," Weyand told Sports Illustrated. "The muscular forces he has to generate are less than half of what an intact sprinter has to generate to go the same speed."
Their research was part of a Point-Counterpoint feature in the current online edition of the Journal of Applied Physiology. In the Counterpoint reply, led by Hugh Herr of MIT, the remaining five scientists contend that studying just one double amputee does not provide enough evidence that the Cheetah legs will consistently provide an advantage. "The notion that lightweight prostheses are the only reason for Pistorius' rapid swing times ignores that he has had many years to train and adapt his neuromuscular system to using prostheses," the authors write.
The published research should not cause the CAS to reconsider and, as of now, Pistorius is still eligible to compete for a spot in London. He seems to be keeping all of this debate in perspective, "When people ask me what it's like having artificial legs, I reply, 'I don't know. What's it like having real legs?'" He adds, "Some people view themselves as disabled because they have one or two disabilities. But what about the millions and millions of abilities they have?"
Welcome to a World Series edition of the Weekly Sports Science Gym Bag, a collection of some of the best stuff I've found in the last week. A few more baseball stories are included, while you watch the Yankees lose in 6 games!
The Overmanager: Why the New York Yankees' Joe Girardi is too smart for his own good
To play in the NFL, you have to make a show of going to college. To play in the NBA, you have to get through high school. To sign a contract with a major league baseball team, all you have to do is convince someone you're 16, provided you weren't born in a country with inconvenient labor laws.Perhaps this goes some way toward explaining both the high reverence in which the intellectual is held in baseball and the low standards necessary to qualify as one...
Running To The Right Beat With the Fall marathon season in full swing, thousands of runners are gearing up for the big day. Just as important as their broken-in shoes and heart rate monitor is their source of motivation, inspiration and distraction: their tunes. Several recent studies try to chase down the connection between our ears and our feet...
Phys Ed: Do More Bicyclists Lead to More Injuries? Recently, surgeons and emergency room physicians at the Rocky Mountain Regional Trauma Center in Denver noticed a troubling trend. They seemed to be seeing cyclists with more serious injuries than in years past. Since many of the physicians at the hospital, a Level I trauma center serving the Denver metropolitan area, were themselves cyclists, they wondered if their sense of things was accurate. So the doctors began gathering data on all cycling-related trauma admittances at the hospital and dividing them into two blocks, one covering 1995-2000 and the other 2001-6...
Football In light of a recent post on the difficulty of changing our decision-making habits - even when we're aware that our habits are biased and flawed - I thought it might be interesting to look at two examples from professional football. Why sports? Given the intense competitive pressure in the NFL - there's a thin line between victory and ignominy - you'd expect head coaches to have corrected many of their decision-making mistakes, especially once those mistakes have been empirically demonstrated. But you'd be wrong.
Consider some research done by David Romer, an economist at UC Berkeley, who published a 2001 paper entitled "Do Firms Maximize? Evidence From Professional Football". The question Romer was trying to answer is familiar to every NFL fan: what to do on 4th down? Is it better to bring on the kicking team for a punt or field-goal attempt? Under what conditions should coaches risk going for it?
Missed Kicks Make Brain See Smaller Goal Post Flubbing a field goal kick doesn’t just bruise your ego — new research shows it may actually change how your brain sees the goal posts. In a study of 23 non-football athletes who each kicked 10 field goals, researchers found that players’ performance directly affected their perception of the size of the goal: After a series of missed kicks, athletes perceived the post to be taller and more narrow than before, while successful kicks made the post appear larger-than-life. Professional athletes have long claimed that their perception changes when they’re playing well — they start hitting baseballs as large as grapefruits, or aiming at golf holes the size of a bucket — but many scientists have been slow to accept that performance can alter visual perception...
Baseball: Head-first Slide Is Quicker
Base running and base stealing would appear to be arts driven solely by a runner's speed, but there's more than mere gristle, bone and lung power to this facet of baseball -- lots of mathematics and physics are at play. Who gets there faster, the head-first slider or the feet-first?
Pump your arms to speed up your legs, thanks to “neural coupling” “Keep pumping your arms!” That’s one of those canonical pieces of advice that it seems every coach gives to his or her runners. The idea is that, late in a run or race when your legs are burning and you’re starting to slow down, if you keep moving arms briskly, your legs will follow. It’s a nice idea — it’s always good to have some concrete piece of advice that you can hang onto when it seems like the world is about to explode. But does it work? Unfortunately, I don’t know. But in the course of researching a completely different topic today, I stumbled on an interesting piece of research by Daniel Ferris, a University of Michigan researcher who’s best known for his research into assisted movement using robotic exoskeletons. The paper, which appeared in the journal Exercise and Sport Science Reviews back in 2006, is called “Moving the arms to activate the legs.” The full text is available here...
The Human Body Is Built for Distance Does running a marathon push the body further than it is meant to go? The conventional wisdom is that distance running leads to debilitating wear and tear, especially on the joints. But that hasn’t stopped runners from flocking to starting lines in record numbers. Last year in the United States, 425,000 marathoners crossed the finish line, an increase of 20 percent from the beginning of the decade, Running USA says. Next week about 40,000 people will take part in the New York City Marathon. Injury rates have also climbed, with some studies reporting that 90 percent of those who train for the 26.2-mile race sustain injuries in the process...
The Playmaker’s Decisions
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