Jake Woolley remembers the day he got his fourth concussion.
It was nice weather for football on Nov. 9 in Pocatello, Idaho: a clear sky, about 55 degrees at kickoff. Nearly 5,000 people had gathered to see the Idaho State Bengals take on the visiting Portland State Vikings.
It was just after 3 p.m. when PSU linebacker Jake Woolley took the field. At siiswx feet, four inches tall and 225 pounds, the 21-year-old junior starter is as athletic as he is powerful.
On the first play of the game, Idaho State quarterback Justin Arias completed a three-yard pass to tight end Josh Cook. Woolley was there, ready to make the tackle.
“I came in as hard as I could to hit the guy,” Woolley recalls. “I thought I was going to kill him.”
What Woolley didn’t see was his teammate, Zach Ka’ahanui, a 265-pound defensive lineman moving in on the same target. As he made the tackle, Ka’ahanui plowed full-speed into his right side. Their helmets crashed together.
“It’s like a quick blackout, like a half a second — DRUSH!” Woolley says, mimicking the sound of the hit.
As he got up Woolley felt lethargic and unstable on his feet, as if his legs had suddenly turned to Jello. “My brain was just overthinking everything,” he says.
Several plays later, Woolley took himself out of the game and was diagnosed with a concussion, the fourth of his playing career and his second in just a few months.

Jake Woolley on the field for the Portland State University Vikings football team.
Image: Portland State University Athletics
Traumatic brain injuries (TBIs) like Woolley’s are part of an increasing and disturbing trend. Part of the rise can be explained by the way they’re now counted. Years ago, medical professionals only considered the possibility for a concussion if the athlete lost consciousness, which happens in just 10% of TBI cases.
The increase in brain injuries could also lie with the evolution of sports. Athletes today are bigger, faster and hit harder than athletes of generations past. Some even theorize that changes in brain chemistry have made today’s young athletes more susceptible to concussions.
The technology surrounding concussions is fundamentally changing, too.
First, advancements in testing technology allow researchers to more deeply understand an athlete’s recovery process. They’ve discovered an athlete can still suffer from a TBI months after the incident, much longer than previously thought. Often, the athlete isn't even aware he's still recovering. He may feel fine, even if his brain is not. As a result, many athletes are returning to play the very sports that caused their concussions in the first place, before their brains can heal.
Athletes who return to play before they’re recovered run three times the risk for getting re-concussed.
With the help of technology, researchers are developing better ways to diagnose and treat TBIs with the hope of reducing concussions in athletes of all ages. It’s part of researchers' efforts to catch up in a field of medicine that some say has been slow to respond to the increasing number of sports-related brain injuries, which have left athletes with lifelong disabilities, mental illnesses, or worse — death.

The Centers for Disease Control and Prevention estimates Americans experience between 1.6 and 3.8 million sports-related traumatic brain injuries each year — and that’s an old statistic (2006). More recent studies estimate numbers closer to 5 million TBIs every year.
Medical research show with increasing clarity that concussions can translate into long-term health problems, including a degenerative brain disease known as chronic traumatic encephalopathy (CTE). The disease’s darkest side has rocked the sports world with several high-profile athlete suicides. Brain studies of Major League Baseball’s Ryan Freel and NFL’s Junior Seau found the athletes had CTE when they killed themselves.
“How you get [CTE] is actually highly debated,” says Steven Broglio, director of the NeuroSport Research Laboratory at the University of Michigan.
Some researchers believe it takes multiple concussions for protein deposits to build up in the brain.
“You can think of those protein deposits within your brain as scar tissue ... that block pathways of function within your brain,” Broglio explains.
Other researchers believe it doesn’t take something as significant as a concussion to cause CTE, but rather, repeated, smaller hits to the head — called subconcussive blows — that contribute to the disease over time.
Broglio says the number of TBIs is increasing, in part because of the way concussions are counted.
“The injuries that we would normally say, ‘Oh, they just got a ding,’ or ‘They just got their bell rung,’ we're associating those with concussions, and not just ignoring them any more,” Broglio says. “Those injuries were always occurring. Now we pay attention to them and take them seriously.”
Over the last decade, the increase in TBIs has lead to increased scrutiny at all levels of sport.
Dr. Jim Chesnutt, medical director for Sport Medicine at Oregon Health and Sciences University in Portland, Ore., says the heightened awareness of traumatic brain injuries and growing number of concussions, especially among young athletes, has lead to “outrage.”
Research into brain injuries, Chesnutt says, is less advanced than other medical fields. Right now, concussion diagnosis relies largely on subjective information from the patient. Medicine is only really beginning to develop biomarkers, or ways to objectively test whether or not someone has experienced a TBI.
Beyond that, Chesnutt says, athletes will react differently to the same type of hit or tackle. What causes a concussion in one person may not cause the same in another.
“We want to be able to hook you up to a test and determine whether you have a concussion,” Chesnutt says. “Unfortunately, the state of affairs for concussions internationally is that we are at the beginning of figuring that out.”
Enter: balance.

Recent brain scans of NFL hall of famer Joe DeLamielleure, who was diagnosed with CTE, the brain injury that affects many former football players.
Image: Jeff Siner/Charlotte Observer/MCT via Getty Images
Over the last several years, balance has emerged as one of the better indicators to determine whether an athlete has suffered a concussion.
New research using accelerometers and other tech devices that measure balance and movement is finding ways to improve current tests. The idea is to make them less subjective, ultimately something sports teams could use in real time.
The brain controls balance, which is why it tends to be one the greatest functions impacted in traumatic brain injury. When the nervous system is working properly, the body is efficient and sways very little. That efficiency gets disrupted after a TBI, causing the body to sway more.
Beyond that, Chesnutt says, balance should be an objective measure — if it can be measured accurately. Current tests, he says, are prone to human error.
The most widely used test developed for brain injury diagnoses is called Balance Error Scoring System (BESS). "It’s a good test. It’s not the best test,” Chesnutt chuckles. “It’s about 40% accurate. Where in the world do we use tests that are 40% accurate? ... Right now it’s the standard of care for testing balance on the sidelines [of a sporting event].”
During the BESS test, the subject performs a series of balance exercises, such as standing on one foot and closing his eyes. The medical professional administering the test visually assesses how often he loses his balance. But it can be hard for the human eye to detect subtle movements that might indicate an athlete is suffering a concussion. Beyond that, research has found the BESS test has a high degree of variability, meaning different trainers might give the same athlete varying diagnoses.g

Jake Woolley taking his final balance test following his fourth concussion in November 2013.
Image: Conrad Wilson
In research set to be published February, OHSU neuroscientist Laurie King has begun to quantify balance.
The subtleties in balance King’s looking for go beyond the obvious. One could recover the ability to stand on his foot for 30 seconds, for example, in a matter of days following a concussion, King says. But that doesn’t mean the athlete can turn to catch a ball, run at full speed or even remember the play. She says it can take months — even longer — for the athlete’s more complex balance skills to recover.
In her study, King attached sensors that measure movement around the waists of athletes who experienced TBIs. She found that without the devices, the BESS test lacked specificity, and produced varied results. The sensors, though, are much more accurate at detecting minute changes in a person’s balance.
“Without the technology, you can’t pick this up,” King says. “These people look normal.”
But King’s research shows the athletes are far from normal. And without a way to quantify the problem, many are returning to the sport where they got concussed — sans recovery.
“The big question with a concussion is: When is a person resolved enough to go back to play?” King says. “Once you’ve had one concussion, you’re three times more likely to have a second one and partly it may be due, we think, because your balance control isn’t back to normal yet.”
If medical teams can quantify an athlete’s balance using technology that measures body movement, King says, they'll be able to prove a patient is still suffering from his or her concussion.
“We know, as clinicians, that patients don’t feel back to normal a lot of times, and yet they’ll come to see their doctor, and you can’t find anything objectively,” King says. “It’s hard to treat; it’s hard to justify referrals to physical therapy or rehabilitation to insurance if you can’t document a problem. And it’s hard to really confidently keep somebody out of the game ... if you can’t document a problem.”
King’s hopes to use sensors in real time, not only to better diagnose concussions, but to determine when an athlete’s fully recovered. Consequently, they'll more confidently make decisions about when that person can go back to play. The idea, she says, is to make sure the athlete has fully healed and, therefore, is less likely to get re-concussed.

Jake Woolley and Dr. Laurie King after Woolley's final balance test.
Image: Conrad Wilson
On a grey winter day on Portland State University's campus, linebacker Jake Woolley walks up and down a dimly lit hallway inside the school’s athletic facility. Weeks have passed since his fourth concussion, and today is his final day of balance tests.
One accelerometer is wrapped around his waist and one on each ankle.
“So he’s going to walk for two minutes,” King says, gesturing to Woolley.
The sensors measure his movements in real time and relay the results to a computer that records Woolley’s gait, as part of his balance.
After each two-minute interval, King and her research assistant add a new task, such as walking and reading aloud. The idea is to see how additional brain function impacts Woolley’s ability to walk in a straight line.
After several variations, the walking portion of the test is complete.
Woolley turns his back to a cement wall. With his feet together and arms crossed across his chest, he stands still. Now the sensors monitor how much his body sways. Like the walking portion of the test, Woolley also completes several variations of the sway test, such as balancing on a foam pad and closing his eyes.
Combined, the tests measure Woolley’s overall balance and how it’s changed since the concussion.

Dr. Laurie King shows one of the APDM's Mobility Lab sensors she uses in her balance research.
Image: Conrad Wilson
The test is called iSway, and is operated by a device called Mobility Lab. It’s developed by a startup at Portland State University called APDM. The hardware consists of three black, smooth devices about the same size as a watch. Each contains an accelerometer and a gyroscope.
The system and its three sensors cost roughly $3,000 — a deal by King’s standards.

Image: Oregon Health and Science University/Dr.Laurie King
“This typically would’ve had to take place in a big, fancy balance disorders lab, with markers all over your body,” King says.
APDM says its Mobility Lab is primarily being used in research settings in over 250 universities, hospitals and clinics. More than a dozen peer-reviewed research paper’s have been published using the technology.
For privacy purposes and because Wolley participates in an ongoing study, King couldn’t provide the athlete's results. But similar findings provide the basic idea: As someone heals from a TBI, his or her balance improves over time.
(The graphic above shows how a concussion can impact balance measurements. The figure on the left (the control) shows the sway of a person without a concussion. The figure on the right shows the sway of someone suffering with a concussion (TBI).)
The idea for balance technology isn’t entirely unique. Other university incubators and companies are developing electronic boards that athletes balance on. Like the device King’s using, the idea is to remove subjectivity from the BESS test.
Others are using technology that many people already carry right in their pockets.
In August, Sway Medical, a Tulsa, Okla.-based startup, released an FDA-cleared app called Sway Balance, which relies on motion sensors already in the iPhone to test for balance. The app walks users through a five-part balance test:

Using the SwayBalance app, an athlete records a baseline test, before any known injury occurs.
Image: Sway Medical
Place feet together with eyes closed.
Put left foot in front of right with eyes closed.
Put right foot in front of left with eyes closed.
Balance on right foot. Lift left foot and close eyes.
Lift right foot and close eyes. Balance on left foot.
All the while, the participant holds the iPhone against his chest.
The test takes about three minutes and spits out a score between 0 - 100, based on measurements taken while completing those tasks. The lower the number, the worse a person's balance.
The scale is arbitrary, but the goal, says SwayBalance Founder and CEO Chase Curtiss, is for an athlete to record a baseline test, before any known injury occurs. That way, coaches and medical staff have a point of comparison if they suspect an athlete has suffered a concussion. Or, he says, to test whether balance has improved after one.
“There’s not a definitive, single thing that can diagnose a concussion,” Curtiss says. “It has to be done by the provider, by the athletic trainer, by the physician. So our tool is just an extra one that helps them make a better judgement on that.”
The “tool” costs $200 per year, making it at the very least an affordable option when it comes to measuring balance.
But it’s more limited, too. Unlike the iSway test, which measures an athlete’s balance via sway, gait, distance and whether he walks in a straight line, Sway Balance simply measures an athlete’s balance by measuring how much his body sways.
Curtiss says the app is still in beta testing, among a pool of over 500 medical professionals. He says several health systems as well as college and pro sports teams are looking to implement it in their sports medicine programs.
It took weeks for Jake Woolley to recover from his fourth concussion. He had a hard time formulating and expressing his thoughts. Headaches followed him throughout the day and he was easily exhausted by appointments where trainers monitored his recovery.
Several weeks later, Woolley says, he attempted a conditioning practice.
“I breezed through it,” he says. “That really was the indicator knowing I was really back to myself.”
But over time, even Woolley’s sense of normalcy seems to have shifted.
“I’ve noticed my memory has gotten worse. My focus has gotten a little worse. I have to really bear down when I’m studying and really just tune into what I have to do,” Woolley says. “I’m pretty much a seasoned veteran in the concussion lifestyle right now.”
Despite technological advancements in concussion diagnosis that prevent athletes from returning to play before they’ve recovered, no app, device or gadget has found a way to prevent such injuries in the first place.
Still, researchers are turning to more accurate, technology-aided tools with the goal of preventing athletes from enduring multiple concussions. For example, in January the Sports Legacy Institute announced a new initiative that would embed sensors inside helmets to count the number of hits to the head athletes at all levels of contact sports sustain, especially during practice. The idea is to give coaches data so they can adjust practices and reduce injury.
Whether tech counts hits or measures balance, the goal is the same: to reduce suffering from lifelong problems like CTE, and ultimately save lives.
Next year, Woolley will be a senior. It’s a big year for any athlete; for most, it’s their last playing at a competitive level.
It’s clear Woolley is conscious of the risks involved with playing, perhaps even a little concerned about what another brain injury might mean for his long-term health. But he doesn’t give much thought to sitting the season out.
“I’m 100% playing,” Woolley says. “The only thing I’m really weighing is if I get another one. What happens next?”