Monday, July 19, 2010

Major League Pitchers 34 Percent More Likely to be Injured than Fielders


Watch out if you are a Major League Baseball (MLB) pitcher prior to the All-Star break. Pitchers are 34 percent more likely to be injured than fielders, according to a study presented today at the American Orthopaedic Society for Sports Medicine’s (AOSSM) Annual Meeting. The study looked into the epidemiology of MLB players’ injuries from 2002 – 2008. It also found that 77 percent of all injuries to pitchers happen before the All-Star Game.

“Even though baseball is a passion of many people and our national pastime, there is very little information about the epidemiology, characteristics or distribution of injuries in Major League Baseball,” said Maj., Matthew Posner, MD, orthopaedic surgeon at the William Beaumont Army Medical Center in El Paso, Texas. “This study attempts to evaluate Major League injuries over the period of six years.”

The study authors analyzed Major League Baseball disabled list data from a single internet website for the years 2002 – 2008. Then they calculated the frequency and proportional distribution of injuries by anatomic region, league, time of season and position. The study found that upper extremity injuries accounted for 51.4 percent of all injuries. Lower extremity injuries accounted for 30.6 percent, while back injuries accounted for 7.4 percent and core muscle injuries accounted for 4.3 percent.

Pitchers had a 34 percent higher injury rate than fielders prior to the All-Star Game, according to the study. Not surprisingly, pitchers experienced 67 percent of the injuries to the upper extremity compared to fielders while fielders also had a greater proportion of the lower extremity injuries and injuries to other anatomic regions, according to the study.

The study also noted that pitchers also spent a greater proportion of days on the disability list (62.4 percent) when compared to fielders (37.6 percent). But both pitchers and fielders spent significantly more days on the disabled list for upper extremity injuries than for lower extremity injuries.

National League or American League? The study found that the distribution of injuries by anatomic region was nearly identical between players in the National League and the American League when all players (pitchers and fielders) were considered. National League players injured their upper extremities 51.7 percent of the time, lower extremities 30.7 percent and other anatomic regions 17.7 percent.

American League players injured their upper extremities 51.1 percent of the time, lower extremities 30.5 percent and other anatomic regions 18.4 percent, according to the study.

As for the timing of the injuries, 74.4 percent of all MLB players’ injuries occurred before the All-Star break. Pitchers sustained 76.5 percent and fielders sustained 71.7 percent of their total respective injuries prior to the All-Star game. Seventy-nine percent of all shoulder and elbow injuries happened to pitchers before the All-Star game and 74.8 percent of all hamstring, quadriceps, groin and core injuries to fielders happened before the All-Star game.

Wednesday, July 7, 2010

Fouls go left: Soccer referees may be biased based on play's direction of motion

Penn study finds left-to-right readers more likely to call foul for right-to-left attacks

Soccer referees may have an unconscious bias towards calling fouls based on a play's direction of motion, according to a new study from the of University of Pennsylvania School of Medicine. Researchers found that soccer experts made more foul calls when action moved right-to-left, or leftward, compared to left-to-right or rightward action, suggesting that two referees watching the same play from different vantage points may be inclined to make a different call. The study appears in the July 7 online edition of PLoS ONE.

It's been documented that individuals who read languages which flow left-to-right are more likely to have a negative bias for events moving in the opposite direction, from right-to-left. In the Penn study of twelve members of the University of Pennsylvania's varsity soccer teams (all native English speaking), researchers found that participants viewing the soccer plays were more likely to call a foul when seeing a right-to-left attack

"The effects are impressive considering that left-moving and right-moving images were identical, with the only difference being that they were flipped along the x-axis to create right-to-left and left-to-right versions," said lead researcher Alexander Kranjec, PhD, a post-doctoral fellow in the Neurology Department at the University of Pennsylvania School of Medicine. "If the spatial biases we observed in this population of soccer players have similar effects on referees in real matches, they may influence particular officials differently: referees on the field will more frequently be in positions that lower their threshold for calling fouls during an attack, compared to assistant referees working the lines."

In real matches, referees and linesmen tend to be exposed to different quantities of right-to-left or left-to-right attacking plays, as referees employ a system to help them cover the field efficiently. Referees are encouraged to use a diagonal patrolling technique, choosing to run either a left or a right diagonal, while the assistant referees are tasked with running the sidelines.

Based on this study, the left diagonal system would favor the offense (viewing more attacks from right-to-left), and the right diagonal system would favor the defense (viewing more attacks from left-to-right). Given the relational opposition, the authors suggest that referees should avoid switching diagonals at halftime.

"There could be an unfair advantage if one team goes into halftime with a lead and the referees switch to a right diagonal system in the second half, favoring both defenses," said Dr. Kranjec. "However, because referees viewing leftward action may be more likely to see a foul when no foul was actually committed, as seemed to be the case when the referee disallowed what should have been the US team's third goal against Slovenia, the bias could work against the offense sometimes."

Study participants called approximately three more fouls when images of soccer plays where viewed from right-to-left (66.5 fouls) compared to mirror images moving left-to-right (63.3 fouls). Participants were statistically more likely to call a foul when seeing a right-to-left attack.

Previous studies suggest that similar directional effects are reversed in populations that read right-to-left languages, but other populations (e.g. Arabic or Hebrew readers) would need to be tested directly to see if the effects reported in this study correlate with reading habits.

The study will be available online at

Friday, July 2, 2010

New World Cup Soccer Ball Will Unsettle Goalkeepers, Predicts Scientist

The new football that is being used for the first time in the World Cup is likely to bamboozle goalkeepers at some stage of the tournament, a leading scientist has warned.

The Adidas ‘Teamgeist’ football has just 14 panels - with fewer seams - making its surface ‘smoother’ than conventional footballs which have a 26 or 32 panel hexagon-based pattern.

This makes it aerodynamically closer to a baseball and, when hit with a slow spin, will make the ball less stable, giving it a more unpredictable trajectory in flight.

“With a very low spin rate, which occasionally happens in football, the panel pattern can have a big influence on the trajectory of the ball and make it more unpredictable for a goalkeeper,” said Dr Ken Bray, a sports scientist at the University of Bath and author of the new popular science book How to score – science and the beautiful game.

“Because the Teamgeist ball has just 14 panels it is aerodynamically more similar to the baseball which only has two panels.

“In baseball, pitchers often throw a ’curve ball’ which is similar to a swerving free kick and the rotating seam disrupts the air flow around the ball in much the same way as a football does.

“Occasionally though, pitchers will throw a ’knuckleball’ which bobs about randomly in flight and is very disconcerting for batters.

“It happens because pitchers throw the ball with very little spin and as the ball rotates lazily in the air, the seam disrupts the air flow around the ball at certain points on the surface, causing an unpredictable deflection.

“With the world’s best players in Germany this summer, there are bound to be plenty of spectacular scoring free kicks.

“But watch the slow motion replays to spot the rare occasions where the ball produces little or no rotation and where goalkeepers will frantically attempt to keep up with the ball’s chaotic flight path.”

The ball, which has been used by teams competing in the World Cup in practice sessions, has already been criticised by England goalkeeper Paul Robinson and Germany goalkeeper Jens Lehmann for its light-weight and unpredictable behaviour.

Psychologists Link Hitting Skills to Vision

Why do some players hit it out of the park, when others can barely get it past the pitcher? Could it be that athletes playing well in a baseball game see the ball as a different size than it really is?

When heavy-hitter Paul Rugani steps up to plate, he's ready to knock a softball out of the park. "It's fun to hit. It's fun to get on base," Rugani says. "I like being up in situations where I can knock runners in."

Good players like Rugani can bring in home runs easily, and many athletes claim when they hit well in a game, the ball appears much bigger than it really is. Now, cognitive psychology student Jessica Witt sets out to find out if the theory is true.

"I watched players play, and after the games were over, I asked them to look at an array of different sized circles and pick which circle they thought best matched the size of the softball," Witt, of the University of Virginia in Charlottesville, tells DBIS.

Witt found players picking the larger circles performed better, proving that a player's perception of the ball's size is somehow linked to his performance. "It's hard to know which direction the effect goes," she says. "Do you see it as bigger and therefore hit better, or are you hitting better and therefore see it as bigger?"

She also found athletes who hit poorly see the ball as being much smaller than it really is. She says, "If we're a poor hitter, we see the world full of really, tiny, tiny, tiny balls that are really difficult to hit."

So to do well in a game, think big to hit big.

Witt recently conducted another study to find out if golfers who do well in a game see the cup as being bigger. Preliminary results suggest golfers do, indeed, see the cup bigger when playing well.

BACKGROUND: Perception and action -- the interactions between mind and body -- could be interlinked. Athletes often say that when they are playing well -- shooting hoops, hitting baseballs, catching football passes -- the ball appears bigger. When they are in a slump, the ball appears smaller. A new study by University of Virginia psychologists has found a connection between batting averages of softball players and how big or small they thought the ball seemed.

ABOUT THE STUDY: The scientists conducted their experiment at several softball fields in Charlottesville and asked players who had finished playing for the day to look at eight different-sized circles on a board, and to pick the one that best represented the size of the softball they had been trying to hit. They compared that data to the hitting percentage of the players for that day. The study found that when players were hitting well, they clearly perceived the ball to be bigger. And when they were hitting less well, they perceived the ball to be smaller. The scientists plan to continue their study on perceived ball size and batting averages under more controlled conditions.

HOW WE SEE "DEPTH": The human visual system is designed to allow us to detect fine detail, track a moving object, see colors, and perceive depth. All these components of a visual scene are processed and merged by the brain so that we observe them as one visual experience. How we recognize that different objects are at different distances from us depends on visual cues. For objects beyond 100 feet, the image that's projected on to the back of the eye is basically the same size to both eyes, so cues of depth perception would include knowing the relative range of sizes of objects in general. If one object partly hides another, we know that the object in front is closer. And as we move our heads and bodies, nearby objects will seem to move more quickly than distant objects, an effect called motion parallax.

For objects closer than 100 feet, we need three-dimensional vision. Because the eyes are separated by about six centimeters, each eye gets a slightly different view of the same object. So when we fixate on one object, we can tell if another object is in front of or behind it, because the object is located in two different places on the images that reach the retinas, or backs of the eyes. This is called disparity. Experiments have found that depth perception likely occurs in the primary visual cortex, where individual neurons receiving input from the retinas of the two eyes fire specifically when retinal disparity exists.

VISION PROBLEMS: If particular parts of the brain are damaged, people may lose some visual perception. They might not be able to recognize faces, for instance (prosopagnosia), or not be able to name colors (color anomia). And sometimes they can lose their stereoscopic vision (visual spatial agnosia) or lose the ability to see objects that are in motion (movement agnosia).

Science of Soccer: Ball Aerodynamics Focus of Research

With the attention of sports fans worldwide focused on South Africa and the 2010 FIFA World Cup, U.S. scientist John Eric Goff has made the aerodynamics of the soccer ball a focus of his research.

In an article appearing in the magazine Physics Today this month, Goff examines the science of soccer and explains how the world's greatest players are able to make a soccer ball do things that would seem to defy the forces of nature.

Goff's article looks at the ball's changing design and how its surface roughness and asymmetric air forces contribute to its path once it leaves a player's foot. His analysis leads to an understanding of how reduced air density in games played at higher altitudes -- like those in South Africa -- can contribute to some of the jaw-dropping ball trajectories already seen in some of this year's matches.

"The ball is moving a little faster than what some of the players are used to," says Goff, who is a professor of physics at Lynchburg College in Virginia and an expert in sports science.

For Goff, soccer is a sport that offers more than non-stop action -- it is a living laboratory where physics equations are continuously expressed. On the fields of worldwide competition, the balls maneuver according to complicated formulae, he says, but these can be explained in terms the average viewer can easily understand. And the outcomes of miraculous plays can be explained simply in terms of the underlying physics.

Goff also is the author of the recently published book, "Gold Medal Physics: The Science of Sports," which uncovers the mechanisms behind some of the greatest moments in sports history, including:

* How did Cal beat Stanford in the last seconds with five lateral passes as the Stanford marching band was coming on to the field?
* How did Doug Flutie complete his "Hail Mary" touchdown pass that enabled Boston College to beat Miami?
* How did Lance Armstrong cycle to a world-beating seven Tour de France victories?
* How did Olympic greats Bob Beamon (long jump), Greg Louganis (diving) and Katarina Witt (figure skating) achieve their record-setting Olympic gold?

The article "Power and spin in the beautiful game" appears in the July, 2010 issue of Physics Today and is available at