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Key to speed? Elite sprinters are unlike other athletes — deliver forceful punch to ground

New research finds that world-class sprinters attack the ground to maximize impact forces and speed

The world’s fastest sprinters have unique gait features that account for their ability to achieve fast speeds, according to two new studies from Southern Methodist University, Dallas.

The new findings indicate that the secret to elite sprinting speeds lies in the distinct limb dynamics sprinters use to elevate ground forces upon foot-ground impact.

“Our new studies show that these elite sprinters don’t use their legs to just bounce off the ground as most other runners do,” said human biomechanics expert and lead author on the studies Ken Clark, a researcher in the SMU Locomotor Performance Laboratory. “The top sprinters have developed a wind-up and delivery mechanism to augment impact forces. Other runners do not do so.”

The new findings address a major performance question that has remained unanswered for more than a decade.

Previous studies had established that faster runners attain faster speeds by hitting the ground more forcefully than other runners do in relation to their body weight. However, how faster runners are able to do this was fully unknown. That sparked considerable debate and uncertainty about the best strategies for athletes to enhance ground-force application and speed.

“Elite speed athletes have a running pattern that is distinct,” Clark said. “Our data indicate the fastest sprinters each have identified the same solution for maximizing speed, which strongly implies that when you put the physics and the biology together, there’s only one way to sprint really fast.”

The critical and distinctive gait features identified by the study’s authors occur as the lower limb approaches and impacts the ground, said study co-author and running mechanics expert Peter Weyand, director of the SMU Locomotor Performance Lab.

“We found that the fastest athletes all do the same thing to apply the greater forces needed to attain faster speeds,” Weyand said. “They cock the knee high before driving the foot into the ground, while maintaining a stiff ankle. These actions elevate ground forces by stopping the lower leg abruptly upon impact.”

The new research indicates that the fastest runners decelerate their foot and ankle in just over two-hundredths of a second after initial contact with the ground.

The researchers reported their findings with co-author and physicist Laurence J. Ryan, research engineer for the SMU Locomotor Performance Laboratory in the Annette Caldwell Simmons School of Education & Human Development.

The finding that elite sprinters apply greater ground forces with a distinctive impact pattern is reported in the Journal of Applied Physiology in the article, “Are running speeds maximized with simple-spring stance mechanics?” It appears online at http://bit.ly/1Be92Mk in advance of appearing in the print journal.

The finding that faster athletes deliver a firm, rapid punch to the ground upon contact is reported in The Journal of Experimental Biology, in the article “Foot speed, foot-strike and footwear: linking gait mechanics and running ground reaction forces.” It appears online at http://bit.ly/1uskM9v.

Studies compared data from competitive sprinters to other athletes
The tests conducted at SMU’s Locomotor Performance Lab compared competitive sprinters to other fast-running athletes.

The competitive sprinting group included track athletes who specialized in the 100- and 200-meter events. More than half had international experience and had participated in the Olympics and Track and Field World Championships.

They were compared to a group of athletes that included competitive soccer, lacrosse and football players.

All the athletes in both groups had mid- and fore-foot strike patterns. Their running mechanics were tested on a custom, high-speed force treadmill that allowed the researchers to capture and analyze hundreds of footfalls at precisely controlled speeds. Video captured for the studies is posted to the SMU Locomotor Performance Lab Youtube channel. Images on flickr are at http://bit.ly/YKwAtB.

The researchers measured ground-force patterns over a full range of running speeds for each athlete from a jog to top sprinting speed.

“We looked at running speeds ranging from 3 to 11 meters per second,” Clark said. “Earlier studies in the field of biomechanics have examined ground reaction force patterns, but focused primarily on jogging speeds between 3 and 5 meters per second. The differences we found became identifiable largely because of the broad range of speeds we examined and the caliber of the sprinters who participated in the study.”

Classic spring model of running does not explain the unique gait features of top sprinters
The contemporary view of running mechanics has been heavily influenced by the simple spring-mass model, a theory first formulated in the late 1980s. The spring-mass model assumes the legs work essentially like the compression spring of a pogo stick when in contact with the ground.

In this theory, during running at a constant speed on level ground, the body falls down out of the air. Upon landing, the support leg acts like a pogo stick to catch the body and pop it back up in the air for the next step.

It’s been generally assumed that this classic spring model applies to faster running speeds and faster athletes as well as to slower ones.

Elite sprinters do not conform to widely accepted theories of running mechanics
Clark, Ryan and Weyand questioned whether such a passive catch-and-rebound explanation could account for the greater ground forces widely understood as the reason why sprinters achieve faster speeds.

After the researchers gathered ground reaction force waveform data, they found that sprinters differed from other athletes. From there they compared the waveforms to those predicted by the simple spring in the classic model.

“The elite sprinters did not conform to the spring-model predictions,” said Clark. “They deviated a lot, specifically during the first half of the ground-contact phase. Our athlete non-sprinters, on the other hand, conformed fairly closely to the spring-model predictions, even at their top speeds.”

Weyand said the new findings indicate that the classic spring model is not sufficient for understanding the mechanical basis of sprint running performance.

“We found all the fastest athletes applied greater ground forces with a common and apparently characteristic pattern that resulted from the same basic gait features,” he said. “What these sprinters do differently is in their wind up and delivery mechanics. The motion of their limbs in the air is distinct; so even though the duration of their limb-swing phase at top speed does not differ from other runners, the force delivery mechanism differs markedly.”

Sprinters have a common mechanical solution for speed — one that athletes who aren’t as fast do not execute.

“This provides scientific information so coaches and athletes can fully identify what to train,” Clark said. “It is our hope that our results can translate into advances in evidence-based approaches to training speed.”

The research was funded by the U.S. Army Medical Research and Materiel Command and SMU’s Simmons School of Education and Human Development. — Margaret Allen

Follow SMUResearch.com on twitter at @smuresearch.

SMU is a nationally ranked private university in Dallas founded 100 years ago. Today, SMU enrolls nearly 11,000 students who benefit from the academic opportunities and international reach of seven degree-granting schools. For more information see www.smu.edu.

SMU has an uplink facility located on campus for live TV, radio, or online interviews. To speak with an SMU expert or book an SMU guest in the studio, call SMU News & Communications at 214-768-7650.

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Culture, Society & Family Energy & Matter Health & Medicine Learning & Education Researcher news SMU In The News

Lexington Herald-Leader: Cuban asks scientist to study physics of flopping

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Kentucky’s Lexington Herald-Leader covered the research of SMU biomechanics expert Peter G. Weyand, who is teaming with Dallas Mavericks owner Mark Cuban to investigate the forces involved in basketball collisions and the possibility of estimating “flopping” forces from video data.

Herald-Leader Journalist Jerry Tipton quoted Weyand in his June 15 UK basketball column on the flopping research, “Cuban asks scientist to study physics of flopping.

Flopping is a player’s deliberate act of falling, or recoiling unnecessarily from a nearby opponent, to deceive game officials. Athletes engage in dramatic flopping to create the illusion of illegal contact, hoping to bait officials into calling undeserved fouls on opponents.

The phenomenon is considered a widespread problem in professional basketball and soccer. To discourage the practice, the National Basketball Association in 2012 began a system of escalating fines against NBA players suspected of flopping, including during the playoffs, “NBA announces anti-flopping rules for playoffs.”

The Cuban-owned company Radical Hoops Ltd. awarded a grant of more than $100,000 to fund the 18-month research study at SMU.

Read the full story.

EXCERPT:
By Jerry Tipton
Herald-Leader

The defender might be a foot taller and 75 pounds heavier. Yet, contact with the smaller player sends him flying backward. When the referee calls charging, even a casual basketball fan senses injustice.

The illogic of these kiddie car-demolishes-pickup truck collisions moved Dallas Mavericks owner Mark Cuban to take action. He commissioned a scientific study of basketball’s all-too-common lapse into kabuki theatre: the offensive foul. Cuban, an unabashed critic of NBA officiating, had his company, Radical Hoops Ltd, donate $100,000 to Southern Methodist University to study the physics involved in these collisions, it was announced last week.

Peter Weyand, an associate professor of applied physiology and biomechanics at SMU, will lead what’s being billed as an 18-month investigation into mass, force and acceleration in baggy shorts. Sir Isaac Newton meets C.M. Newton.

Weyand and his team will try to determine how much force is required to “legitimately” knock a defender off his feet. They also hope to develop a metric to determine if such a force existed in any particular block/charge incident. In theory, a video review using this metric would lead to punishment for flopping.

Meanwhile, referees roll their eyes.

“Basketball officiating is an art,” said John Hampton, Kentucky native and Southeastern Conference official. “It is not a science. I am extremely skeptical of the whole project.”

Read the full story.

Follow SMUResearch.com on Twitter.

For more information, www.smuresearch.com.

SMU is a nationally ranked private university in Dallas founded 100 years ago. Today, SMU enrolls nearly 11,000 students who benefit from the academic opportunities and international reach of seven degree-granting schools. For more information see www.smu.edu.

SMU has an uplink facility located on campus for live TV, radio, or online interviews. To speak with an SMU expert or book an SMU guest in the studio, call SMU News & Communications at 214-768-7650.

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Culture, Society & Family Energy & Matter Health & Medicine Learning & Education Researcher news SMU In The News Student researchers

HuffPost: Mark Cuban donates $100,000 to research NBA flopping

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News blog Huffington Post picked up the video coverage by KDAF’s CW33 Nightcap News of the research of SMU biomechanics expert Peter G. Weyand, who is teaming with Dallas Mavericks owner Mark Cuban to investigate the forces involved in basketball collisions and the possibility of estimating “flopping” forces from video data.

Huffington Post reposted the Nightcap News video at “Mark Cuban Gives $100K to SMU to Fight NBA Flopping

KDAF’s CW33 Nightcap News coverage, Mark Cuban Gives $100K to SMU to Fight NBA Flopping, was posted June 7.

Flopping is a player’s deliberate act of falling, or recoiling unnecessarily from a nearby opponent, to deceive game officials. Athletes engage in dramatic flopping to create the illusion of illegal contact, hoping to bait officials into calling undeserved fouls on opponents.

The phenomenon is considered a widespread problem in professional basketball and soccer. To discourage the practice, the National Basketball Association in 2012 began a system of escalating fines against NBA players suspected of flopping, including during the playoffs, “NBA announces anti-flopping rules for playoffs.”

The Cuban-owned company Radical Hoops Ltd. awarded a grant of more than $100,000 to fund the 18-month research study at SMU.

Watch the video at Nightcap News.

EXCERPT:
By Barry Carpenter
Nightcap News

The NBA–full of the biggest, fastest athletes in the world and all too often some of the worst actors. Witness flopping.
“This first play is an example that will be penalized.” The narrator on the video said.

The video shows the small player fighting through a pick and sending the much larger player flying.

As explained by the narrator, impossible.

“However the contact of the player is inconsistent with the grossly embellished fall to the floor.”

It happens all the time in the NBA and that’s apparently why the league issued this “What’s a flop and What’s not” training video for the 2012-2013 season.

Technically–flopping is defined by the as a physical act that appears to have been intended to cause the referees to call a foul on another player.

For those who don’t like basketball–let’s take it from the hardwood to the hallway.

Robert and Claire are both heading for the Nightcap coffee pot–at the same time–when all of the sudden the two make contact. Robert is jolted back, he stumbles and falls–looking for a little help.

That is a classic flop–and if Robert was in the NBA he could be fined $5,000.00.

Speaking of money—Dallas Mavericks owner Mark Cuban wants to understand the dynamics of flopping and is giving SMU biomechanics experts a $100,000.00 grant to see how much contact is needed for a player to really flop.

SMU officials say their findings may lead to video reviews of flopping.

Watch the video at Nightcap News.

Follow SMUResearch.com on Twitter.

For more information, www.smuresearch.com.

SMU is a nationally ranked private university in Dallas founded 100 years ago. Today, SMU enrolls nearly 11,000 students who benefit from the academic opportunities and international reach of seven degree-granting schools. For more information see www.smu.edu.

SMU has an uplink facility located on campus for live TV, radio, or online interviews. To speak with an SMU expert or book an SMU guest in the studio, call SMU News & Communications at 214-768-7650.

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Culture, Society & Family Energy & Matter Health & Medicine Learning & Education Researcher news SMU In The News Student researchers

Star Telegram: Eliminate flopping? Godspeed, Mark Cuban

Big Mac Blog

Fort Worth Star Telegram sports writer Mac Engel covered the research of SMU biomechanics expert Peter G. Weyand, who is teaming with Dallas Mavericks owner Mark Cuban to investigate the forces involved in basketball collisions and the possibility of estimating “flopping” forces from video data.

The coverage in Engel’s The Big Mac Blog, “Eliminate flopping? Godspeed, Mark Cuban,” was posted June 11.

Flopping is a player’s deliberate act of falling, or recoiling unnecessarily from a nearby opponent, to deceive game officials. Athletes engage in dramatic flopping to create the illusion of illegal contact, hoping to bait officials into calling undeserved fouls on opponents.

The phenomenon is considered a widespread problem in professional basketball and soccer. To discourage the practice, the National Basketball Association in 2012 began a system of escalating fines against NBA players suspected of flopping, including during the playoffs, “NBA announces anti-flopping rules for playoffs.”

The Cuban-owned company Radical Hoops Ltd. awarded a grant of more than $100,000 to fund the 18-month research study at SMU.

Read the full story

EXCERPT:
By Mac Engel
Star Telegram

Must be great to have Mark Cuban cash.

In front of Mark is a pile of $100,000 that he can:
a.) Burn
b.) Issue a research grant on NBA players flopping.

The obvious choice is B, all the way. This is the definition of money well spent.

Since Cuban bought the Mavs no one in the NBA has leaned on the league for a better product, from the fan experience to the refs to now – no flopping. Refs in the NBA have sucked for years, they still do, because it’s an impossible job and the only good ref is the one you don’t notice.

It’s odd – when the Mavs won the NBA title in 2011, the refs were incredible. Probably just a coincidence.

Now Cuban is working on the widespread epidemic of NBA flopping by granting $100K to SMU to solve this massive crisis.

Only there is no solution, even the best player Cuban agrees this is a fruitless exercise.

“I think we’re trying; you’re never going to get rid of it but you have to limit it,” Dirk Nowitzki told a small group of reporters on Monday at a Dallas YMCA. “I think it’s also part of sports. In any sports, it’s a part. It’s part of winning. Some people are smart; some people do a little extra thing to sell a call. To me, that’s part of sports. You don’t want to be obvious; the really, really bad ones you’d love to get rid of those.

Read more here: http://sportsblogs.star-telegram.com/mac-engel/2013/06/eliminate-flopping-godspeed-mark-cuban.html#storylink=cpy

Read the full story

Follow SMUResearch.com on Twitter.

For more information, www.smuresearch.com.

SMU is a nationally ranked private university in Dallas founded 100 years ago. Today, SMU enrolls nearly 11,000 students who benefit from the academic opportunities and international reach of seven degree-granting schools. For more information see www.smu.edu.

SMU has an uplink facility located on campus for live TV, radio, or online interviews. To speak with an SMU expert or book an SMU guest in the studio, call SMU News & Communications at 214-768-7650.

Categories
Culture, Society & Family Energy & Matter Health & Medicine Learning & Education Researcher news SMU In The News Student researchers

KERA: Fed Up With ‘Flopping,’ Mark Cuban Funds SMU Study

flop

KERA journalist Lauren Silverman covered the research of SMU biomechanics expert Peter G. Weyand, who is teaming with Dallas Mavericks owner Mark Cuban to investigate the forces involved in basketball collisions and the possibility of estimating “flopping” forces from video data.

The coverage, “Fed Up With ‘Flopping,’ Mark Cuban Funds SMU Study,” was posted June 7.

Flopping is a player’s deliberate act of falling, or recoiling unnecessarily from a nearby opponent, to deceive game officials. Athletes engage in dramatic flopping to create the illusion of illegal contact, hoping to bait officials into calling undeserved fouls on opponents.

The phenomenon is considered a widespread problem in professional basketball and soccer. To discourage the practice, the National Basketball Association in 2012 began a system of escalating fines against NBA players suspected of flopping, including during the playoffs, “NBA announces anti-flopping rules for playoffs.”

The Cuban-owned company Radical Hoops Ltd. awarded a grant of more than $100,000 to fund the 18-month research study at SMU.

Read the full story

EXCERPT:
By Lauren Silverman
KERA

Phony falls in basketball just got serious. Dallas Mavericks owner Mark Cuban has teamed up with biomechanics experts at Southern Methodist University to study “flopping” — when a player deliberately falls to deceive referees into thinking there’s been a foul.

Flopping is considered a widespread problem in basketball. In 2012, the NBA began a system of escalating fines against NBA players suspected of flopping. In fact, the league implemented a special anti-flopping fine system for the current playoffs. (Watch out, Tim Duncan!) Now, NBA commissioner David Stern is considering increasing the penalties.

Right now, the first violation results in a $5,000 fine (check out the full breakdown at NBA.com). If a player violates the anti-flopping rule five times or more, “he will be subject to discipline that is reasonable under the circumstances, including an increased fine and/or suspension.”

The problem is, it can be hard to tell whether a player is faking a fall or really got knocked off balance. That’s why Cuban has spent more than $100,000 to fund a research study at SMU in Dallas. Biomechanics expert Peter Weyand, who leads the research team, says, “There has been a lot of research into balance and falls in the elderly, but relatively little on active adults and athletes.”

Read the full story

Follow SMUResearch.com on Twitter.

For more information, www.smuresearch.com.

SMU is a nationally ranked private university in Dallas founded 100 years ago. Today, SMU enrolls nearly 11,000 students who benefit from the academic opportunities and international reach of seven degree-granting schools. For more information see www.smu.edu.

SMU has an uplink facility located on campus for live TV, radio, or online interviews. To speak with an SMU expert or book an SMU guest in the studio, call SMU News & Communications at 214-768-7650.