Muscle Memory Is Real And Can Help Your Game

You’ll hear the same thing over and over on high school and college football fields this month. “We just have to get our reps in.” “Time to knock the rust off and find our rhythm.” “Its all about timing and getting everyone in sync.”  

The common theme for players is trying to increase the efficiency of their thinking and their movements, better known as muscle memory.  By repeating the same motions and plays, practice may not become perfect but it certainly will improve.  Now, neuroscientists at the University of Pittsburgh School of Medicine have found that brains actually do become more energy efficient after numerous repetitions by decreasing the electrical activity between neurons.

Unlike its meaning in strength conditioning, muscle memory in skill development is also referred to as motor learning.  By stringing together an entire series of micro movements, whether it be a QB throwing a back shoulder pass or a linebacker executing an open field tackle, the recipe for the whole process becomes a procedural memory stored, obviously, in the brain not the muscles.  Located in the brain’s primary motor cortex, this neural network has been shown to decrease in activity as athletes go through the learning process as it finds the most economical connection pathways between neurons.

Neuroscientist Peter Strick, professor in the Department of Neurobiology at the Pitt School of Medicine, wondered if this decline in metabolic activity coincided with a decrease in the number of neurons firing.  He and his research team trained monkeys to do two tasks, one where they had to learn to anticipate a point appearing on a screen and one where they had to learn a short sequence of movements without any visual cues.  The second task simulated a motor learning experience where they had to string together a complete movement, like throwing a bullet into double coverage.

They found that the level of neuron firing was the same with both tasks but the metabolic or connection activity required was lower for the internally remembered task.  The research was just published in Nature Neuroscience.

“This tells us that practicing a skilled movement and the development of expertise leads to more efficient generation of neuron activity in the primary motor cortex to produce the movement. The increase in efficiency could be created by a number of factors such as more effective synapses, greater synchrony in inputs and more finely tuned inputs,” Dr. Strick noted. “What is really important is that our results indicate that practice changes the primary motor cortex so that it can become an important substrate for the storage of motor skills. Thus, the motor cortex is adaptable, or plastic.”

So, those endless drills and repetition really do physically change the structure of the brain.  Getting football movements installed as muscle memory lets the player perform them automatically without thinking about each movement component.

To continue with mental reps even after the two a day practices end, many young QBs are turning to cognitive training tools, like the Axon QB app for iPad.  The sooner the better before the season starts.

Helmet Reveals Data About High School Football Player's Broken Neck

For the crowd watching an Illinois high school football game last fall, it was a sickening feeling watching one of their Unity Rockets' cornerbacks collapse to the ground after delivering a heads-down tackle on an opposing running back (see video here.) 

For Steven Broglio, an assistant professor of kinesiology at the University of Michigan, it was a mixed feeling of concern and curiosity as to the extent of the injury.  Since 2007, Broglio has been collecting data on the violent collisions that occur in high school football and their contribution to concussions and other head injuries.

Unity players use helmets with padded sensors called the Head Impact Telemetry System.
Using a sensor similar to what is used in car air bags, the HITS helmets record and transmit the magnitude of each impact and its location on the helmet to a computer located on the sideline within about 10-20 seconds.  Broglio is able to monitor these collisions and alert the coaching staff if an impact exceeds the threshold known to cause concussions, about 90-100 g-force. Listen to Broglio describe the HITS research.

In the last four years, Broglio has recorded over 120,000 football collisions with 25 resulting in a concussion for the player.  However, on this night, he would record data on a much more rare injury - a broken neck.  After briefly losing consciousness on the field, the Unity cornerback was taken to a hospital emergency room and was diagnosed with a concussion and a stable left C6 facet fracture, otherwise known as a broken neck.  Data from the collision showed the hit occurred at the top right side of the helmet at a amazing 114 g-force.  Just for comparison, a shuttle launch is about 3 g-force while a rolling fighter pilot sustains about 5-10 g-force.

Thankfully, the player was released from the hospital 48 hours later with a hard neck collar.  While his football season was over, he returned to play basketball twelve weeks later.

Broglio describes the encounter in a letter to the New England Journal of Medicine.

The goal of the research is to perfect the technology so that similar, less expensive systems can be used on many more football sidelines.  Broglio said a number of other researchers at universities across the nation, including Virginia Tech, the University of North Carolina and Dartmouth, also are using the system as the basis for studies of biomechanical processes caused by concussions and traumatic brain injuries. The current system has a price tag of about $60,000 while the customization to each helmet costs an additional $1,000.  "Ultimately, we're trying to use these measures to predict concussion," Broglio said. "If someone exceeds a certain level then we would know they have a concussion and we could pull them."

With the recent attention to concussions at the NFL level, there is hope that research will also benefit high school and college players. "To us, the larger public health issue is with the 1.5 million high school kids that play football each year. Not the 1,500 that play in the NFL," Broglio said.

Related Articles: New Return-To-Play Guidelines For Sports Concussions and NFL Concussions Taking Bigger Toll On Players

Computerized Concussion Testing Yields More Cautious Return To Play Timeline

When computerized neuropsychological testing is used, high school athletes suffering from a sports-related concussion are less likely to be returned to play within one week of their injury, according to a study in The American Journal of Sports Medicine. Unfortunately, concussed football players are less likely to have computerized neuropsychological testing than those participating in other sports.

A total of 544 concussions were recorded by the High School Reporting Information Online surveillance system during the 2008-2009 school year. Researchers looked at each of those instances to see what caused the injury, what sport was being played, what symptoms were experienced, what type of testing was used, and how soon the athletes returned to play.

When looking at the causes and duration of concussions, the research found that:

* 76.2% of the concussions were caused by contact with another player, usually a head-to-head collision
* 93.4% of concussions caused a headache; 4.6% caused loss of consciousness
* 83.4% experienced resolution of their symptoms within a week, while 1.5% had symptoms that lasted longer than a month.

Computerized neuropsychological testing was used in 25.7% of concussions, and in those cases, athletes were less likely to return to play within one week, than those athletes for whom it was not used. Interestingly, however, researchers found that injured football players were less likely to be examined using the computerized neuropsychological testing than injured athletes participating in other sports.

"Although it is now recognized as one of 'the cornerstones of concussion evaluation,' routine neuropsychological testing in the setting of sports-related concussion is a relatively new concept," write the authors, William P. Meehan III, MD, Pierre d'Hemecourt, MD, and R. Dawn Comstock, PhD. "This is the first study, of which we are aware, to query the use of computerized neuropsychological testing in high school athletes using a large, nationally representative sample."

Source: High School Concussions in the 2008-2009 Academic Year: Mechanism, Symptoms, and Management. The American Journal of Sports Medicine, 2010; 38 (12): 2405 DOI: 10.1177/0363546510376737

See also: NFL Concussions Taking Bigger Toll On Players and Football Players May Still Injure Brain Even Without A Concussion

Football Players May Still Injure Brain Even Without A Concussion

Thomas Talavage, co-director of the Purdue MRI Facility, prepares to test a Jefferson High School football player. (Credit: Purdue University photo/Andrew Hancock)

A study by researchers at Purdue University suggests that some high school football players suffer undiagnosed changes in brain function and continue playing even though they are impaired.
"Our key finding is a previously undiscovered category of cognitive impairment," said Thomas Talavage, an expert in functional neuroimaging who is an associate professor of biomedical engineering and electrical and computer engineering and co-director of the Purdue MRI Facility.

The findings represent a dilemma because they suggest athletes may suffer a form of injury that is difficult to diagnose.

"The problem is that the usual clinical signs of a head injury are not present," said Larry Leverenz, an expert in athletic training and a clinical professor of health and kinesiology. "There is no sign or symptom that would indicate a need to pull these players out of a practice or game, so they just keep getting hit."

Findings are detailed in a research paper appearing online this week in the Journal of Neurotrauma.
The team of researchers screened and monitored 21 players at Jefferson High School in Lafayette, Ind.
"The athletes wore helmets equipped with six sensors called accelerometers, which relay data wirelessly to equipment on the sidelines during each play," said Eric Nauman, an associate professor of mechanical engineering and an expert in central nervous system and musculoskeletal trauma.

Impact data from each player were compared with brain-imaging scans and cognitive tests performed before, during and after the season. The researchers also shot video of each play to record and study how the athletes sustained impacts.

Whereas previous research studying football-related head trauma has focused on players diagnosed with concussions, the Purdue researchers tested all of the players. They were surprised to find cognitive impairment in players who hadn't been diagnosed with concussions.

The research team identified 11 players who either were diagnosed by a physician as having a concussion, received an unusually high number of impacts to the head or received an unusually hard impact. Of those 11 players, three were diagnosed with concussions during the course of the season, four showed no changes and four showed changes in brain function.

"So half of the players who appeared to be uninjured still showed changes in brain function," Leverenz said. "These four players showed significant brain deficits. Technically, we aren't calling the impairment concussions because that term implies very specific clinical symptoms, such as losing consciousness or having trouble walking and speaking. At the same time, our data clearly indicate significant impairment."

The findings support anecdotal evidence that football players not diagnosed with concussions often seem to suffer cognitive impairment.

Researchers evaluated players using a GE Healthcare Signa HDx 3.0T MRI to conduct a type of brain imaging called functional magnetic resonance imaging, or fMRI, along with a computer-based neurocognitive screening test.

"We're proud of our association with Purdue and feel longitudinal studies will provide a valuable platform to better study brain injuries," said Jonathan A. Murray, general manager of cross business programs for GE Healthcare.

The research could aid efforts to develop more sensitive and accurate methods for detecting cognitive impairment and concussions; more accurately characterize and model cognitive deficits that result from head impacts; determine the cellular basis for cognitive deficits after a single impact or repeated impacts; and develop new interventions to reduce the risk and effects of head impacts.

"By integrating the fMRI with head-based accelerometers and computer-based cognitive assessment, we are able to detect subtle levels of neurofunctional and neurophysiological change," Nauman said. "These data provide an opportunity to accurately track both the initial changes as well as the recovery in cognitive performance."

(Credit: iStockphoto/Bill Grove

The ongoing research may help to determine how many blows it takes to cause impairment, which could lead to safety guidelines on limiting the number of hits a player receives per week.  "We're not yet sure exactly how many hits this is, but it's probably around 50 or 60 per week, which is not uncommon," Nauman said. "We've had kids who took 1,600 impacts during a season."

The research paper was written by Nauman, Leverenz, Talavage, Katie Morigaki, a graduate student in the Department of Health and Kinesiology, biomedical engineering graduate student Evan Breedlove, mechanical engineering graduate student Anne Dye, electrical and computer engineering graduate student Umit Yoruk, and Henry Feuer, a physician and neurosurgeon in the Department of Neurosurgery at the Indiana University School of Medicine.

Feuer is a neurosurgical consultant to the National Football League's Indianapolis Colts and a member of NFL subcommittees assessing the effects of mild traumatic brain injury.

The researchers studied the football players last season and are continuing the work this season.
The helmet-sensor data demonstrated that undiagnosed players who didn't show impairment received blows in many areas of the head, but the undiagnosed players who showed impairment received a large number of blows primarily to the top and front. This part of the brain is involved in "working memory," including visual working memory, a form of short-term memory for recalling shapes and visual arrangement of objects such as the placement of furniture in a room, Nauman said.
"These are kids who put their head down and take blow after blow to the top of the head," said Nauman, who also is an associate professor of biomedical engineering and basic medical sciences and leads Purdue's Human Injury Research and Regenerative Technologies Laboratory. "We've seen this primarily in linebackers and linemen, who tend to take most of the hits."

Helmet sensor data indicate impact forces to the head range from 20 to more than 100 Gs.
"To give you some perspective, a roller coaster subjects you to about 5 Gs and soccer players may experience up to 20 G accelerations from heading the ball," Nauman said.
Head impacts cause the brain to bounce back and forth inside the skull, damaging neurons or surrounding tissue. The trauma can either break nerve fibers called axons or impair signaling junctions between neurons called synapses.

The findings suggest the undiagnosed players suffer a different kind of brain injury than players who are diagnosed with a concussion.

"To be taken out of a game you have to show symptoms of neurological deficits -- unsteady balance, blurred vision, ringing in the ears, headaches and slurred speech," Leverenz said. "Unlike the diagnosed concussions, however, these injuries don't affect how you talk, whether you can walk a straight line or whether you know what day it is."

The fMRI reveals information about brain metabolism and blood flow, showing which parts of the brain are most active during specific tasks, Talavage said.

"One of the most challenging aspects of treating concussions is diagnosing the part of the brain that has been damaged," he said.

The fMRI data from before, during and after the season were compared to see whether there was any difference in brain activity that indicated impairment. The players also were studied using a standard cognitive test to show how well they were able to remember specific letters, words and patterns of lines.

The work may enable researchers to learn whether high school players accumulate damage over several seasons or whether they recover fully from season to season. The researchers have found that players diagnosed with concussions or who showed marked cognitive impairment had not yet recovered by the end of the season.

New preliminary data, however, suggests the players might recover before the start of the next season, but additional research is needed to determine the extent of recovery, Talavage said.
The work brings together faculty members from Purdue's College of Engineering and the new College of Health and Human Sciences along with research partners at GE Healthcare. The multidisciplinary team includes researchers specializing in neuroimaging, brain health, biomechanics, clinical sports medicine and analytical modeling.

The research group, called the Purdue Acute Neural Injury Consortium, also is studying ways to reduce traumatic brain injury in soldiers who suffer concussions caused by shock waves from explosions.  "There are numerous parallels between head injuries experienced by soldiers and football players," Nauman said.

Other researchers in the consortium are Dennis A. Miller, a sports medicine expert; Charles A. Bouman, the Michael J. and Katherine R. Birck Professor of Electrical and Computer engineering and co-director of the Purdue MRI Facility; and Alexander L. Francis, an expert in learning and cognitive processing and an associate professor of speech, language and hearing sciences.

The work has been funded by the Indiana Department of Health and GE Healthcare. The researchers would like to extend their study to more high schools and are seeking additional funding for the work.
Researchers are working to create a helmet that reduces the cumulative effect of impacts, said John C. Hertig, executive director of the Alfred Mann Institute for Biomedical Development at Purdue.

"We're funding the development of a novel injury mitigation system created by researchers at Purdue for use in sports or military helmets," Hertig said. "This technology is targeted at mitigating the collective impacts absorbed by the brain in such a way as to dissipate the harmful energy that occurs during repeated impacts. Football linemen, soccer and hockey players, and others will benefit from the re-engineering of a sports helmet design created by Eric Nauman and his team."

Source:  Purdue University and Thomas M. Talavage, Eric Nauman, Evan L. Breedlove, Umit Yoruk, Anne E Dye, Katie Morigaki, Henry Feuer, Larry J. Leverenz. Functionally-Detected Cognitive Impairment in High School Football Players Without Clinically-Diagnosed Concussion. Journal of Neurotrauma, 2010; : 101001044014052 DOI: 10.1089/neu.2010.1512

See also: Hockey Hits Are Hurting More and Lifting The Fog Of Sports Concussions