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Mild problem-solving task improves brain function after a concussion, new study suggests

A simple cognitive task as early as four days after a brain injury activates the region that improves memory function, and may guard against developing depression or anxiety

Concern is growing about the danger of sports-related concussions and their long-term impact on athletes. But physicians and healthcare providers acknowledge that the science is evolving, leaving questions about rehabilitation and treatment options.

Currently, guidelines recommend that traumatic brain injury patients get plenty of rest and avoid physical and cognitive activity until symptoms subside.

But a new pilot study looking at athletes with concussions suggests total inactivity may not be the best way to recover after all, say scientists at Southern Methodist University, Dallas, where the research was conducted.

The study found that a simple cognitive task as early as four days after a brain injury activated the region that improves memory function and can guard against two hallmarks of concussion — depression and anxiety.

“Right now, if you have a concussion the directive is to have complete physical and cognitive rest, no activities, no social interaction, to let your brain rest and recover from the energy crisis as a result of the injury,” said SMU physiologist Sushmita Purkayastha, who led the research, which was funded by the Texas Institute for Brain Injury and Repair at UT Southwestern Medical Center, Dallas.

“But what we saw, the student athletes came in on approximately the third day of their concussion and the test was not stressful for them. None of the patients complained about any symptom aggravation as a result of the task. Their parasympathetic nervous system — which regulates automatic responses such as heart rate when the body is at rest — was activated, which is a good sign,” said Purkayastha, an assistant professor in the Department of Applied Physiology and Wellness.

The parasympathetic nervous system is associated with better memory function and implicated in better cardiovascular function. It also helps to regulates stress, depression and anxiety — and those are very common symptoms after a concussion.

“People in the absolute rest phase after concussion often experience depression,” Purkayastha added. “In the case of concussion, cutting people off from their social circle when we say ‘no screen time’ — particularly the young generation with their cell phones and iPads — they will just get more depressed and anxious. So maybe we need to rethink current rehabilitation strategy.”

The new study addresses the lack of research upon which to develop science- and data-based treatment for concussion. The findings emerged when the research team measured variations in heart rate variability among athletes with concussions while responding to simple problem-solving and decision-making tasks.

While we normally think of our heart rate as a steady phenomenon, in actuality the interval varies and is somewhat irregular — and that is desirable and healthy. High heart rate variability is an indicator of sound cardiovascular health. Higher levels of variability indicate that physiological processes are better controlled and functioning as they should, such as during stressful (both physical and challenging mental tasks) or emotional situations.

Concussed athletes normally have lowered heart rate variability.

For the new study, Purkayastha and her team administered a fairly simple cognitive task to athletes with concussions. During the task, the athletes recorded a significant increase in heart rate variability.

The study is the first of its kind to examine heart rate variability in college athletes with concussions during a cognitive task.

The findings suggest that a small measure of brain work could be beneficial, said co-investigator and neuro-rehabilitation specialist Kathleen R. Bell, a physician at UT Southwestern.

“This type of research will change fundamentally the way that patients with sports and other concussions are treated,” said Bell, who works with brain injury patients and is Chair of Physical Medicine and Rehabilitation at UT Southwestern. “Understanding the basic physiology of brain injury and repair is the key to enhancing recovery for our young people after concussion.”

The researchers reported their findings in the peer-reviewed Journal of Head Trauma Rehabilitation, in the article “Reduced resting and increased elevation of heart rate variability with cognitive task performance in concussed athletes.”

Co-authors from SMU Simmons School include Mu Huang and Justin Frantz; Peter F. Davis and Scott L. Davis, from SMU’s Department of Applied Physiology and Wellness; Gilbert Moralez, Texas Health Presbyterian Hospital, Dallas; and Tonia Sabo, UT Southwestern.

Concussion symptom improved with simple brain activity
Volunteer subjects for the study were 46 NCAA Division I and recreational athletes who participate in contact-collision sports. Of those, 23 had a physician-diagnosed sports-related concussion in accordance with NCAA diagnostic criteria. Each of them underwent the research testing within approximately three to four days after their injury.

Not surprisingly, compared to the athletes in the control group who didn’t have concussions, the athletes with concussions entered answers that were largely incorrect.

More importantly, though, the researchers observed a positive physiological response to the task in the form of increased heart rate variability, said Purkayastha.

“It’s true that the concussed group gave wrong answers for the most part. More important, however, is the fact that during the task their heart rate variability improved,” she said. “That was most likely due to the enhancement of their brain activity, which led to better regulation. It seems that engaging in a cognitive task is crucial for recovery.”

Heart rate variability is a normal physiological process of the heart. It makes possible a testing method as noninvasive as taking a patient’s blood pressure, pulse or temperature. In the clinical field, measuring heart rate variability is an increasingly common screening tool to see if involuntary responses in the body are functioning and being regulated properly by the autonomic nervous system.

The parasympathetic is blunted or dampened by concussion
Abnormal fluctuations in heart rate variability are associated with certain conditions before symptoms are otherwise noticeable.

Monitoring heart rate variability measures the normal synchronized contractions of the heart’s atriums and ventricles in response to natural electrical impulses that rhythmically move across the muscles of the heart.

After a concussion, an abnormal and unhealthy decline in heart rate variability is observed in the parasympathetic nervous system, a branch of the autonomic nervous system. The parasympathetic is in effect blunted or dampened after a concussion, said Purkayastha.

As expected, in the current study, heart rate variability was lower among the athletes with concussions than those without.

New findings add evidence suggesting experts rethink rehab
But that changed during the simple cognitive task. For the athletes with concussions, their heart rate variability increased, indicating the parasympathetic nervous system was activated by the task.

Heart rate variability between the concussed and the controls was comparable during the cognitive task, the researchers said in their study.

“This suggests that maybe we need to rethink rehabilitation after someone has a concussion,” Purkayastha said. — Margaret Allen, SMU

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Study: Impoverished students and black students suffer greater impact from closure of Houston schools

“It is particularly troubling that not only are economically disadvantaged and black students more likely to experience closures, but they are the least likely to subsequently transfer to the types of high-performing schools that are critical to their future academic success,” — Meredith Richards, SMU

School closures disproportionately displace impoverished and black students, according to a new study from researchers at Southern Methodist University and Rice University’s Houston Education Research Consortium.

In a look at the Houston Independent School District’s school closures between 2003 and 2010, researchers found that schools with a higher proportion of black students were particularly likely to be targeted by closures, said education policy researcher Meredith Richards, co-author of the study and assistant professor in the Department of Education Policy and Leadership at SMU, Dallas.

“This is particularly concerning,” Richards said, “given the pernicious history of inequity and structural racism and the already problematic achievement gaps between blacks and whites in Houston and nationally.”

Also, more than 90 percent of students were economically disadvantaged, qualifying for free or reduced meals under the federal school lunch program.

School closures in the face of tight budgets are a challenge nationwide — for both urban and rural districts.

The researchers note that students displaced by school closures in Houston did generally transfer to schools that were better performing than those that closed. However, there were concerning racial differences in transfer patterns.

White and Asian students displaced by closure are twice as likely as black and Hispanic students to transfer to high-performing schools, while most black and Hispanic students transferred to low-quality schools.

“Unfortunately, the negative effects of closures are disproportionately borne by Houston’s most disadvantaged students,” Richards said. “It’s also important to note that, despite going to higher quality schools on average, we find that students generally have slower achievement growth after closures — even students who transfer to high-quality schools. This suggests that although school closures may be necessary for budgetary reasons, they are not likely to be a successful reform strategy for improving student achievement.”

Findings of the study are presented by HERC as a research brief. For the study’s data, Richards and her colleague Kori Stroub, a researcher at Rice’s HERC, examined 4,168 students displaced by 27 of HISD’s 55 school closures between 2003 and 2010 and compared them with a matched group of students that did not experience closures during the same time period.

The paper used data from the state of Texas supplied by the Texas Education Research Center at the University of Texas at Austin.

School closures impact students as well as the wider community
Richards — whose research generally concerns the impact of a broad range of policies, particularly their unintended consequences for disadvantaged groups — first witnessed the impact of school closures while a post-doctoral researcher at the University of Pennsylvania. Philadelphia’s school district proposed closing 37 schools, she recalls.

“The response of the local community and the media was overwhelming — a number of people were even arrested in protesting the closures,” she said. “I became interested in the effect of closures on not only students, but on the local communities in which schools are such important cultural institutions.”

Closures in Philadelphia, Chicago, Detroit and other major cities in the Midwest and Northeast have received considerable attention.

“Kori and I realized that districts like Houston were more quietly shuttering urban schools with much less attention,” Richards said. “Thus, we applied for and received a $50,000 grant from the Spencer Foundation to allow us to study the effects of closures in this understudied context.”

Vast majority of students in closed schools are economically disadvantaged
The researchers found that 91 percent of students in HISD schools that were closed were economically disadvantaged, meaning they qualified for free or reduced meals under the National School Lunch and Child Nutrition Program, compared with 80 percent in HISD as a whole.

Also, 43 percent of students affected by those school closures were black, even though only 27 percent of HISD’s students were black.

Stroub, who is lead author on the study, and Richards, the grant’s principal investigator, also examined whether students from the closed schools transferred to high-performing schools (those in the top third of HISD schools based on Texas Assessment of Knowledge and Skills, or TAKS, test scores) or low-performing schools (those in the bottom third of HISD schools based on TAKS scores).

High-achieving students were more likely to transfer to high-performing schools
Fifty-two percent of displaced students transferred to schools in the bottom third of the district in math achievement and 43 percent of displaced students transferred to schools in the bottom third of HISD in reading achievement.

Only 21 percent of displaced students transferred to high-performing schools in terms of math achievement and 18 percent transferred to schools with high reading achievement.

In addition, high-achieving students (those in the top third of HISD students) were 1.6 times more likely to transfer to high-performing schools than low-achieving students (those in the bottom third of HISD students).

However, low- and high-achieving students were about equally likely to transfer to low-performing schools (55 percent and 49 percent, respectively).

Students of color transferred disproportionately to low-achieving schools
Breaking things down by race, the researchers found that 51 percent of displaced white students transferred to schools that ranked in the top third of schools in terms of achievement and only 28 percent of black students and 20 percent of Hispanic students transferred to high-achieving campuses. By comparison, 26 percent of displaced white students, 42 percent of displaced black students and 53 percent of displaced Hispanic students transferred to low-achieving schools.

“It is particularly troubling that not only are economically disadvantaged and black students more likely to experience closures, but they are the least likely to subsequently transfer to the types of high-performing schools that are critical to their future academic success,” Richards said.

School closures and transfers take a toll on student achievement over time
The researchers also focused on the impact of school closures on student achievement over time, as measured by the math and reading TAKS scores of the displaced students and the type of schools to which they transferred.

Overall:
During their first year at a new school, displaced students got 1.3 more questions correct on their math TAKS compared with nondisplaced students. There was no significant change in their reading TAKS results.

In the years following closure, displaced students had slower academic progress than their nondisplaced peers. By their fourth year at a new school, displaced students got 0.3 fewer questions correct on their math TAKS and one fewer question correct on their reading TAKS compared with nondisplaced students.

Students transferred to low-performing schools:
During their first year at a new school, there was no effect on the math TAKS scores of displaced students, but the same students got two fewer questions correct on their reading TAKS compared with nondisplaced students.

In the years following closure, displaced students who transferred to low-performing schools had slower academic achievement than their nondisplaced peers. By their fourth year at a new school, displaced students got 4.1 fewer questions correct on their math TAKS and 3.6 fewer questions correct on their reading TAKS than nondisplaced students.

Students that transferred to high-performing schools:
During their first year at a new school, displaced students got 3.1 more questions correct on their math TAKS and 1.9 more questions correct on their reading TAKS than nondisplaced students.

In the years following closure, displaced students who transferred to high-performing schools had slower growth in academic achievement than their nondisplaced peers. By their fourth year at a new school, the initial bump in achievement after closure had narrowed to 2.2 questions on the math TAKS and 1.3 questions on the reading TAKS.

Findings imply closure policies should mitigate impact on students
“To help minimize the negative effects of closures, the district must be judicious in closing only the lowest-performing schools,” the authors said.

“In addition, students must be offered high-performing transfer options to the extent feasible. We recommend that displaced students are reassigned to schools that are significantly higher-performing than the schools from which they came,” they note. “We also suggest that displaced students be given preferential admissions or reserved slots in several high-performing campuses across the district.”

Stroub said this was especially important because low-performing schools tend to cluster geographically.

“The bulk of displaced students may not live near a meaningfully higher-performing school to which they can be re-zoned,” he said.

“However, HISD can leverage its well-developed choice programs to provide displaced students increased access to higher-performing schools.”

The study and research brief are Part 1 of a larger project, “Evaluating the impact of school closures in Houston ISD.” — Rice University, Houston, and SMU

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Inverse: There is no limit to human speed — Fast, faster, fastest, and fastest-er.

“Weyand doesn’t see a future where records stop being broken; there are just too many different ways to legally influence performance through better training and better technology.”

Science writer Jacqueline Ronson tapped the expertise of SMU biomechanics expert Peter Weyand for an article on the news web site Inverse.com that examines the possibility for humans to continue running faster and faster — and faster.

Ronson cites physiologist Weyand’s numerous research findings, which have explored the mechanics of how sprinters like Usain Bolt and other world-class athletes are able to run so fast that they continually break speed records. The article “There is no limit to human speed” published Aug. 11, 2016.

Weyand, director of the SMU Locomotor Performance Laboratory, is one of the world’s leading scholars on the scientific basis of human performance. His research on runners, specifically world-class sprinters, looks at the importance of ground forces for running speed, and has established a contemporary understanding that spans the scientific and athletic communities.

In particular, Weyand’s finding that speed athletes are not able to reposition their legs more rapidly than non-athletes debunked a widespread belief. Rather, Weyand and his colleagues have demonstrated sprinting performance is largely set by the force with which one presses against the ground and how long one applies that force.

Weyand is Glenn Simmons Centennial Chair in Applied Physiology and professor of biomechanics in the Department of Applied Physiology & Wellness in SMU’s Annette Caldwell Simmons School of Education and Human Development.

Read the full story.

EXCERPT:

By Jacqueline Ronson
Inverse.com

Usain Bolt seems to run impossibly fast: His record time of 9.58 seconds in the 100-meter sprint seems unbeatable — yet that’s what was said about so many of the record holders before.

But surely there must be a hard limit to human speed, after which no more records will be broken? Humans, after all, cannot run infinitely fast.

Peter Weyand, a physiologist who has studied the biomechanics of running for two decades, says no.

“You can always be confident, no matter how fast somebody runs, it’s possible to go faster,” he tells Inverse. “You’re never going to have absolutely perfect conditions and an absolutely perfect person and an absolutely perfect race all come together at the same time.”

Here’s a neat fact: If you can sprint, you can be as fast as Usain Bolt. Back in the late 1990s, Weyand and a team of researchers measured a bunch of different people running at their top speed, and they had something in common: Within a very small margin, they all took the same amount of time to swing a leg through the stride from back to front. “Whether you’re fast, slow, or in between, the repositioning time for the limb at top speed is basically the same,” he says.

Read the full story.

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Scientific American: Blade Runners — Do High-Tech Prostheses Give Runners an Unfair Advantage?

Four years after Oscar Pistorius made history at the London Olympics, the question remains unanswered

Science writer Larry Greenemeier cited the research of SMU biomechanics expert Peter Weyand for an article in Scientific American that examines the pros and cons of carbon-fiber blade prosthetics used by athlete amputees.

Greenemeier cites Weyand’s research findings from a study of Olympic blade-runner Oscar Pistorius to determine whether the double-amputee had a competitive advantage from his carbon-fiber prosthetic legs. The article “Blade Runners: Do High-Tech Prostheses Give Runners an Unfair Advantage?” published Aug. 5, 2016.

Weyand, director of the SMU Locomotor Performance Laboratory, is one of the world’s leading scholars on the scientific basis of human performance. His research on runners, specifically world-class sprinters, looks at the importance of ground forces for running speed, and has established a contemporary understanding that spans the scientific and athletic communities.

In particular, Weyand’s finding that speed athletes are not able to reposition their legs more rapidly than non-athletes debunked a widespread belief. Rather, Weyand and his colleagues have demonstrated sprinting performance is largely set by the force with which one presses against the ground and how long one applies that force.

Weyand is Glenn Simmons Centennial Chair in Applied Physiology and professor of biomechanics in the Department of Applied Physiology and Wellness in SMU’s Annette Caldwell Simmons School of Education and Human Development.

Read the full story.

EXCERPT:

By Larry Greenemeier
Scientific American

Paralympic long jump champ Markus Rehm’s bid to compete in the 2016 Rio de Janeiro Olympics fell short in July when he could not prove that his carbon-fiber “blade” prosthesis didn’t give him an advantage. His baffling case serves as a reminder that four years after South African sprinter Oscar Pistorius propelled himself into history as the first amputee Olympic athlete to compete using blade prostheses, the technology’s impact on performance remains unclear despite ongoing research.

Blade prostheses, like Rehm uses on his right leg and Pistorius used on both, share some characteristics with biological limbs. The blades store energy as they bear the runner’s weight and then release it as the runner pushes off the ground, much the way a leg’s calf muscles and Achilles’ tendons spring and recoil. But an important difference is the foot, which on a blade prosthetic does not pivot or generate its own energy. A biological foot has muscle fibers that help it push off the ground in a way that creates “metabolic efficiency so your muscles don’t have to put all of the work back in with every step as you’re running,” says David Morgenroth, an assistant professor in the University of Washington’s Department of Rehabilitation Medicine…

…Shortly after track and field’s governing body, the International Association of Athletics Federations (IAAF), banned Pistorius in 2008 from competing against so-called “able-bodied” competitors, he underwent a series of tests at Rice University’s Locomotion Laboratory in an attempt to be reinstated. The researchers concluded that Pistorius used 17 percent less energy than that of elite sprinters on intact limbs. The tests also revealed that it took the South African 21 percent less time to reposition, or swing, his legs between strides. Big disagreements arose over how to interpret the research.

Southern Methodist University’s Peter Weyand and Matt Bundle from the University of Montana saw a clear overall advantage in Pistorius’s faster leg swings and more energy-efficient stride, which they said could create up to a seven-second advantage in the 400-meter race. “The more mass you have closer to the axis—in this case, your hips—the easier it is to stop the rotation and then turn it around,” Bundle says. “Whereas if you had that same amount of mass located a long way away from the axis—in your lower legs and feet—it becomes much more difficult to stop it and get it going in the opposite direction.”

Read the full story.

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Scientific American: Have We Reached the Athletic Limits of the Human Body?

Record-breaking has slowed, but science could find new ways to make us keep getting stronger and faster

Science writer Bret Stetka tapped the expertise of SMU biomechanics expert Peter Weyand for an article in Scientific American examining the potential for humans to continue improving strength and speed beyond what has already been achieved.

Stetka quotes Weyand for his expertise on the mechanics of running and speed of world-class sprinters like Usain Bolt. The article “Have We Reached the Athletic Limits of the Human Body?” published Aug. 5, 2016.

Weyand, director of the SMU Locomotor Performance Laboratory, is one of the world’s leading scholars on the scientific basis of human performance. His research on runners, specifically world-class sprinters, looks at the importance of ground forces for running speed, and has established a contemporary understanding that spans the scientific and athletic communities.

In particular, Weyand’s finding that speed athletes are not able to reposition their legs more rapidly than non-athletes debunked a widespread belief. Rather, Weyand and his colleagues have demonstrated sprinting performance is largely set by the force with which one presses against the ground and how long one applies that force.

Weyand is Glenn Simmons Centennial Chair in Applied Physiology and professor of biomechanics in the Department of Applied Physiology and Wellness in SMU’s Annette Caldwell Simmons School of Education and Human Development.

Read the full story.

EXCERPT:

By Bret Stetka
Scientific American

At this month’s summer’s Olympic Games in Rio, the world’s fastest man, Usain Bolt—a six-foot-five Jamaican with six gold medals and the sinewy stride of a gazelle—will try to beat his own world record of 9.58 seconds in the 100-meter dash.

If he does, some scientists believe he may close the record books for good.

Whereas myriad training techniques and technologies continue to push the boundaries of athletics, and although strength, speed and other physical traits have steadily improved since humans began cataloguing such things, the slowing pace at which sporting records are now broken has researchers speculating that perhaps we’re approaching our collective physiological limit—that athletic achievement is hitting a biological brick wall.

Common sense tells us that of course there are limits to athletic achievement: Barring some drastic amendment to the laws of physics, no human will ever run at the speed of sound. And physiologically speaking there’s only so much calcium that can flood into a muscle cell causing it to contract; there’s only so much oxygen our red blood cells can shuttle around.

In this vein, in 2008 running enthusiast and Stanford University biologist Mark Denny published a study attempting to determine if there are absolute limits to the speeds animals can run. To do so he analyzed the records of three racing sports with long histories of documentation: track and field and horse racing in the U.S., along with English greyhound racing…

…Bolt may be comforted to know that for Southern Methodist University physiology professor Peter Weyand, one of the leading experts on the biology of performance, we humans haven’t quite reached our athletic ceiling. Weyand explains that when considering endurance, for example, there are two paths to improvement: either increasing the amount of blood being pumped out of the heart or increasing the oxygen concentration in the blood itself, as is the case with blood doping. “I don’t think we’ve hit our limits yet,” he believes, “I think people will find ways to enhance oxygen delivery through the body and squeeze more performance out of humans. The only question is will these approaches be considered legal.”

Read the full story.