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In the News, Sleep, Sports, Stanford News

Sleep = one of the keys to Golden State Warriors’ success

Sleep = one of the keys to Golden State Warriors' success

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All-Star shooting guard Klay Thompson loves to take three pointers, and he’s good at it – he’s second in the league in made threes this season. (His teammate and fellow “Splash Brother” Stephen Curry holds the number one spot.) Thompson also loves to sleep, and perhaps the two aren’t unrelated. The Associated Press was there when Stanford sleep researcher Cheri Mah paid a visit to the Golden State Warriors’ locker room last week, sharing some tips with the team.

Much of Mah’s work focuses on sleep and athletic performance, and she says sleep is something that’s often put on the back burner, especially with elite teams who have grueling  schedules. From the piece:

“It’s one of the first things we sacrifice but one of the most important,” Mah said Thursday. “Changing time zones frequently, that can affect circadian rhythms. Really, it was addressing improving and optimizing sleep and recovery.”

Getting more sleep is something Thompson has no problems with. “I know how important recovery is,” he said in the article. “We play such a long season. And I love to sleep, so it was good hearing that if you want to be at optimal peak performance you’ve got to get your eight hours, or at least try to. You can’t be hanging out long hours at night.”

Previously: Superathletes sleep more, says Stanford researcherAsk Stanford Med: Cheri Mah responds to questions on sleep and athletic performance, Expert argues that for athletes, “sleep could mean the difference between winning and losing,” Why your sleeping habits may be preventing you from sticking to a fitness routine and A slam dunk for sleep: Study shows benefits of slumber on athletic performance
Photo by Chilli Head

Neuroscience, Research, Sports, Stanford News

Forces at work in concussions more complicated than previously thought, new Stanford study reveals

Forces at work in concussions more complicated than previously thought, new Stanford study reveals

640px-Hischool_football_sunsetThe college bowls of New Year’s Day are behind us, and many football fans are already looking forward to next month’s Super Bowl. But they’re also talking more about the traumatic head injuries that plague football players, which scientists and clinicians still don’t understand fully.

One Stanford team is measuring the physical forces that an athlete’s head undergoes in a much more detailed way than in past studies, using a specially-outfitted mouthguard that we wrote about last year. Just before Christmas, Stanford bioengineer David Camarillo, PhD, and his team published a paper in the Annals of Biomedical Engineering that provides a much more complete picture of head injuries among athletes.

Helmets used in football and other sports are only evaluated on how well they protect in three directions of movement: front/back, up/down, and left/right. But, as a press release from the university notes, researchers suspect that rotational accelerations (roll, pitch, yaw) play an important role in serious injuries.

The team customized a commercially available mouthguard to measure movement in all six directions, and they recorded 500 impacts on Stanford football players, local boxers and mixed martial arts athletes. Two of the impacts resulted in concussions. The researchers analyzed the impacts and found that using six degree-of-freedom data proved to be more predictive of injuries than the current three degree-of-freedom standard. They also found that one particular part of the brain is more likely involved in concussion injuries. The release details these findings:

The current work… has helped identify a brain structure that bears closer scrutiny for its potential role in concussion symptoms. While the two concussion impacts inflicted very different magnitude and directional forces on the head, computer models indicated that they both put strain on a particular part of the brain, the corpus callosum. Previous concussion studies have identified the corpus callosum as a potential injury site.

“One of the things the corpus callosum does is manage depth perception and visual judgment by communicating and integrating information from each eye across the left and right hemisphere of the brain,” said lead author Fidel Hernandez, a mechanical engineering graduate student in Camarillo’s lab. “If your eyes can’t communicate, your ability to perceive objects in three dimensions may be impaired and you may feel out of balance, which is a classic concussion symptom.”

At the beginning of this year, a new law went into effect in California limiting the time high school football players’ full-contact practice time to just two 90 minute sessions per week; the new law also bans out-of-season full-contact practice. Texas has had a similar law on the books since 2013. The laws indicate the growing concern over head injuries, and more accurate information from studies like Camarillo’s can help coaches and parents decide when a player needs to step off the field.

Beyond influencing possible changes to industry standards, another possible implications for Camarillo’s research is that it will allow coaches to remotely monitor impact forces that players undergo. Many players under-report impact injuries, something that complicates understanding the phenomena. Accurate measurements can help clarify the picture.

Previously: Mouthguard technology by Stanford bioengineers could improve concussion measurementStanford undergrad studies cellular effects of concussionsKids and concussions: What to keep in mindDeveloping a computer model to better diagnose brain damage, concussions and Study suggests football-related concussions caused by series of hits, not a single blow.
Photo by  Jacoplane

Bioengineering, Neuroscience, Sports, Stanford News

Mouthguard technology by Stanford bioengineers could improve concussion measurement

Mouthguard technology by Stanford bioengineers could improve concussion measurement

mouthguard on helmetPerhaps you’ve heard of helmet sensors to alert emergency contacts if a rider falls from a bicycle. Now, Stanford bioengineers are working with mouthguards that measure and report head impacts in football players in real time, and the research could have implications for understanding the forces of head traumas from more common accidents.

Stanford News reports:

For the past few years, David Camarillo, an assistant professor of bioengineering, and his colleagues have been supplying Stanford football players with special mouthguards equipped with accelerometers that measure the impacts players sustain during a practice or game. Previous studies have suggested a correlation between the severity of brain injuries and the biomechanics associated with skull movement from an impact.

Camarillo’s group uses a sensor-laden mouthguard because it can directly measure skull accelerations – by attaching to the top row of teeth – which is difficult to achieve with sensors attached to the skin or other tissues. So far, the researchers have recorded thousands of these impacts, and have found that players’ heads frequently sustain accelerations of 10 g forces, and, in rarer instances, as much as 100 g forces. By comparison, space shuttle astronauts experience a maximum of 3 g forces on launch and reentry.

Camarillo, PhD, and colleagues including bioengindeering doctoral student Lyndia Wu are enhancing the technology and refining the data collected, detecting head impacts in a lab test-dummy with 99 percent accuracy.  They’ve recently published a paper on their work in IEEE Transactions on Biomedical Engineering.

“Our football team has been extremely cooperative and interested in helping solve this problem,” Camarillo told writer Bjorn Carey. “What we are learning from them will help lead to technologies that will one day make bike riding and driving in your car safer too.”

Previously: Is repetitive heading in soccer a health hazard?Now that’s using your head: Bike-helmet monitor alerts emergency contacts after a crash and Stanford researchers working to combat concussions in football
Photo by Linda A. Cicero/Stanford News Service

Neuroscience, Research, Science, Sports

World Cup debut of robotic exoskeleton grounded in more than two decades of scientific research

World Cup debut of robotic exoskeleton grounded in more than two decades of scientific research

Neuroscience took center stage at the World Cup as a young man who was paralyzed from the waist down wearing an exoskeleton suit controlled by his brain waves kicked a soccer ball to open the tournament.

A post on the NIH Director’s Blog notes that the dramatic debut of the robotic exoskeleton was “was grounded in more than 20 years of scientific studies” and offers “an inspiring glimpse of just one of the many things that can be achieved when science is supported over the long haul.” The piece goes on to explain the evolution of the research and a detailed look at the exoskeleton’s design and function:

The leader of the team, Miguel Nicolelis, a Brazilian who co-directs the Duke University Center for Neuroengineering in Durham, N.C., has been working on brain-machine interfaces in various animal models for decades. In a pioneering experiment involving a monkey equipped with brain sensors that sent real-time commands associated with leg movements, Nicolelis showed that the animal could spur a computer-controlled robot located thousands of miles away to walk by simply thinking about walking.

Now, Nicolelis has shown that a similar feat is possible with humans, using a robotic exoskeleton system built in conjunction with German colleagues who are part of the non-profit Walk Again Project. The paralyzed person wears a special cap that contains electrodes that read their brainwaves. To move the plastic-and-aluminum exoskeleton, a person needs to imagine actually doing each phase of his or her desired movements; for example, “start walking,” “turn right,” “kick the ball,” “sit down,” and so on. These brain signals are sent to a computer inside a backpack worn by the person, where they are translated to commands that control the exoskeleton.

Previously: Support for robots that assist people with disabilities and Custom-made exoskeleton helps young girl with muscle disease use her arms

Nutrition, Research, Sports

Elite rugby players may have more diverse gut microbiota, study shows

Elite rugby players may have more diverse gut microbiota, study shows

Andrew TrimbleThe Irish national rugby team might seem like a uniform study population, but it turns out their gut landscapes are highly diverse territories. That’s according to a new study published in BMJ’s Gut. Scientists from the Alimentary Pharmabiotic Centre at University College Cork and Teagasc Food Research Centre, Moorepark, in conjunction with the Irish Rugby Football Union studied forty male professional rugby players with a mean age of 29 in training leading up to the last Rugby World Cup and two male control groups. The researchers found that the rugby players, whose exercise and dietary habits tended to be more extreme than those of the Irish general public, also had gut microbiota that were more diverse.

From a release:

The athletes are an exceptional group in terms of their dietary intake, fitness/endurance and now we know, in relation to their gut microbiota! This high diversity is particularly linked with exercise and protein consumption and suggests that eating specific proteins and/or exercise can provide a means of increasing microbial diversity in the gut.

This is the first report that exercise increases microbial diversity in humans. While we and others have previously shown that diet influences microbial diversity, we can now report that protein consumption, in particular, positively correlates with microbial diversity.

According to the study, “The results provide evidence for a beneficial impact of exercise on gut microbiota diversity but also indicate that the relationship is complex and is related to accompanying dietary extremes.”

Previously: Stanford team awarded NIH Human Microbiome Project grant, How exercise may affect gut hormones, weight loss and Researchers manipulate microbes in gut
Photo by ASSOCIATED PRESS

Complementary Medicine, Health and Fitness, In the News, Sports

How do you get through the NBA Finals? Practice, practice, practice (yoga)

How do you get through the NBA Finals? Practice, practice, practice (yoga)

LeBron JamesA student in a yoga class I attended in Berkeley, Calif. last Saturday asked the teacher about the origin of the Sanskrit chant we had just repeated. He explained that the words were the lyrics from the theme song to Battlestar Galactica. Inviting pop-culture references into the sometimes-serious space of the studio is a terrific way to normalize the complementary medicine practice. So is welcoming 6’8″, 250-pound athletes to an activity often stereotyped as being for the petite, female and flexible.

That is to say that LeBron James takes yoga. In case you somehow missed it, the Miami Heat star got sidelined by cramps near the end of Game 1 of the NBA Finals. A piece on Sports Illustrated‘s Point Forward describes how yoga played a role in James’ recovery and preparation for the next game of the series:

[Readying his body for Game 2] included, among a more extensive hydration regimen, James’ decision to attend a Sunday morning yoga class at the Heat’s team hotel in San Antonio.

“Yoga isn’t just about the body, it’s also about the mind and it’s a technique that has really helped me,” James told Brian Windhorst (then of the Cleveland Plain-Dealer) in 2009. “You do have to focus because there’s some positions that can really hurt you at times if you aren’t focused and breathing right.”

Upon his arrival in Miami, James also credited yoga for his supernatural level of endurance. Only Kevin Durant has logged more total minutes since James joined the Heat in 2011.

The piece notes that James’ teammate Dwayne Wade and the Heat’s playoffs opponents, the San Antonio Spurs, are among the other NBA affiliates who stand in Mountain Pose.

Previously: Third down and ommm: How an NFL team uses yoga and other tools to enhance players’ well-beingNIH to host Twitter chat on science of yoga and Expert argues that for athletes, “sleep could mean the difference between winning and losing”
Via Tiffany Russo Yoga
Photo by ASSOCIATED PRESS

Ethics, Research, Sexual Health, Sports, Stanford News, Women's Health

"Drastic, unnecessary and irreversible medical interventions" imposed upon some female athletes

"Drastic, unnecessary and irreversible medical interventions" imposed upon some female athletes

Four female athletes were required to undergo “partial clitorectomies” and gonadectomies (removal of gonads) as a result of the current gender-policing polices of major sports governing bodies, according to an article published this week in the British Medical Journal.

The article, co-written by Stanford bioethicist Katrina Karkazis, PhD, raises concerns that new policies that use testosterone testing to determine eligibility for elite female athletes accused of having “male-like attributes” have resulted in unnecessary interventions that are both “invasive and irreversible.” The paper was timed to coincide with an editorial that she and Barnard College’s Rebecca Jordan-Young, PhD, wrote for the New York Times, which was previously discussed here.

Karkazis told me that both the journal article and the editorial were written in response to a case study published last year in the Journal of Clinical Endocrinology and Metabolism by physicians who conducted the medical procedures on the four female athletes. The athletes, ages 18-21 and all from developing countries, had tested high for naturally occurring testosterone levels. Their identities remain confidential, but the physicians who performed the surgeries and wrote the report acknowledged that there was no medical need for the procedures, which have been used as treatments for intersex conditions. Karkazis and colleagues argue that not only is there no medical benefit to such procedures, they also make no difference to athletic ability. From the journal article:

Clitoridectomy is not medically indicated, does not relate to real or perceived athletic “advantage,” and is beyond the policies’ mandate. Moreover, this technique is long eschewed because it has poor cosmetic outcomes and damages sexual sensation and function. Clitoral surgery should have no role in interventions undertaken for athletes’ eligibility or health.

Karkazis and her colleagues go on to refute the logic of using testosterone level testing in women as grounds for exclusion from competition as having no scientific grounds, and quote sports officials as saying that female athletes with unusually high naturally occurring testosterone levels have no more competitive advantage that other elite athletes. Karkazis and Jordan-Young wrote in the Times:

Sports officials (the report does not identify their governing-body affiliation) sent the young women to a medical center in France, where they were put through examinations that included blood tests, genital inspections, magnetic resonance imaging, X-rays and psychosexual history… Since the athletes were all born as girls but also had internal testes that produce unusually high levels of testosterone for a woman, doctors proposed removing the women’s gonads and partially removing their clitorises. All four agreed to undergo both procedures; a year later, they were allowed to return to competition.

Quite simply, these young female athletes were required to have drastic, unnecessary and irreversible medical interventions if they wished to continue in their sports.

Previously: Arguing against sex testing in athletes, Is the International Olympic Committee’s policy governing sex verification fair? and Researchers challenge proposed testosterone testing in select female Olympic athletes

In the News, Orthopedics, Research, Sports

Helping to prevent ACL tears in young athletes

Helping to prevent ACL tears in young athletes

Luke RichessonA clinical report recently released by the American Academy of Pediatrics provides 14 recommendations for doctors who work with children in school or sports programs to reduce the risk of knee injuries such as anterior cruciate ligament (ACL) injuries, which are increasingly common in that demographic. A Reuters piece notes, “The ACL can tear when athletes quickly change direction, land on their leg incorrectly, stop suddenly or collide with each other” and that injury to this key knee-stabilizing ligament is especially common in college-aged women.

More from the article:

The report says neuromuscular training programs that strengthen leg muscles, improve stability and teach people how to safely move should be encouraged.

The authors write that the components of training programs that have effectively reduced the risk of ACL tears include plyometric or jump training and tailored feedback for individual athletes.

Programs that also include strength training have been among the most successful in reducing ACL injury rates, they add.

I connected with orthopedic surgeon Jason Dragoo, MD, head team physician for Stanford Football and a Stanford Athletics team physician, who said each day his clinic sees an average of four new ACL tears, approximately 25 percent of those in adolescents.

Dragoo noted that numerous programs for ACL prevention are being distributed in athletic programs, including those at Stanford. Working with the University’s strength and conditioning program and using research from the Human Performance Lab and methods such as the Oslo 11+ program, physicians and trainers integrate ACL-prevention exercises into athletes’ warm-up and conditioning routines, teaching the body to move with healthy alignment. “A lot of ACL tears occur during fatigue,” Dragoo said. “We’re training [athletes] to move correctly even when they’re tired.”

Previously: How much for those healthy knees?Exploring the use of yoga to improve the health and strength of bones and Researchers call for improvements to health screenings for female college athletes
Photo by ASSOCIATED PRESS

Ethics, In the News, Sports, Stanford News, Women's Health

Arguing against sex testing in athletes

Arguing against sex testing in athletes

Testosterone does not a man – nor a woman – make. So argues Stanford medical anthropologist Katrina Karkazis, PhD, in a New York Times op-ed today. She cites evidence against the scientific and ethical soundness of sex-testing policies used since 2011 by sports governing organizations including the International Olympic Committee, the Fédération Internationale de Football Association and the International Association of Athletics Federations.

From the piece:

Rather than trying to decide whether an athlete is “really” female, as decades of mandatory sex tests did, the current policy targets women whose bodies produce more testosterone than is typical. If a female athlete’s T level is deemed too high, a medical team selected by the sport’s governing bodies develops a “therapeutic proposal.” This involves either surgery or drugs to lower the hormone level. If doctors can lower the athlete’s testosterone to what the governing bodies consider an appropriate level, she may return to competition. If she refuses to cooperate with the investigation or the medical procedures, she is placed under a permanent ban from elite women’s sports.

Sports authorities argue that screening for high T levels is needed to keep women’s athletics fair, reasoning that testosterone improves performance. Elite male athletes generally outperform women, and this difference has been attributed to men’s higher testosterone levels. Ergo, women with naturally high testosterone are thought to have an unfair advantage over other women.

But these assumptions do not match the science. A new study in Clinical Endocrinology fits with other emerging research on the relationship between natural testosterone and performance, especially in elite athletes, which shows that T levels can’t predict who will run faster, lift more weight or fight harder to win. The study, of a sample of 693 elite athletes, revealed a significant overlap in testosterone levels among men and women: 16.5 percent of the elite male athletes had testosterone in the so-called female range; nearly 14 percent of the women were above the “female” range.

Karkazis concludes, “Barring female athletes with high testosterone levels from competition is a solution to a problem that doesn’t exist. Worse, it is pushing young women into a choice they shouldn’t have to make: either to accept medically unnecessary interventions with harmful side effects or to give up their future in sports.”

Previously: Is the International Olympic Committee’s policy governing sex verification fair?, Researchers challenge proposed testosterone testing in select female Olympic athletes and Gender ambiguity gets attention

Health and Fitness, Public Health, Research, Sports

Lingering effects of injuries sideline many former college athletes later in life

Lingering effects of injuries sideline many former college athletes later in life

basketball playerWhile playing sports in college, it wasn’t uncommon to see medical trainers tape up teammates’ bruised ribs or administer cortisone shots so that athletes wouldn’t have to sit out a game. I always felt fortunate that I suffered only a series of sprained ankles, but concern for my health grew after reading about new research showing that many college athletes are inactive later in late due to the long-term consequences of past injuries.

The study, which appears in the American Journal of Sports Medicine, examined more than 230 men and women who were former Division I athletes and 225 who didn’t play high-level sports in college. Individuals ranged from 40-65 years old. As reported in a recent Health Day story, the Indiana University researchers’ findings showed:

Former Division I athletes were more than twice as likely to have physical problems that limited their daily activities and exercise. Sixty-seven percent of these former athletes said they had suffered a major injury and 50 percent said they had chronic injuries during college, compared with 28 percent and 26 percent, respectively, among non-athletes.

The study also found that 70 percent of athletes said they had practiced or played with an injury, compared with 33 percent of non-athletes. Forty percent of athletes were diagnosed with osteoarthritis after college, compared with 24 percent of non-athletes.

Previous joint injuries may increase the risk of developing osteoarthritis, the study authors said.

The former college athletes also had higher levels of depression, fatigue and poor sleep than non-athletes, according to the study, which was published recently in the American Journal of Sports Medicine.

Previously: Is repetitive heading in soccer a health hazard?, Study shows men, rather than women, may be more prone to ACL injuries and Researchers call for improvements to health screenings for female college athletes
Photo by K.M. Klemencic

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