Category Archives: Science and Medicine

Feeding the Hogs

Photo by Jeffreyw.

It’s a common refrain among college coaches (particularly line coaches) that their players need to eat more.  A lot more.  A big-framed, yet gangly kid coming out of high school might’ve lived on cereal, chips, and energy drinks when he played varsity, but that won’t cut it on the big stage.  A football player needs serious calories to gain and maintain playing weight.  Put another way, tight ends don’t become OTs without a little effort.

We can get a good guess at just how many calories players need by using an updated version of the Harris-Benedict equation.  Though the original version is nearly a hundred years old, this formula is a classic (and still solid) way of estimating someone’s caloric expenditure over the course of a day.

Picture a typical college lineman, say somebody about 6’2”, 295.  If you plug these stats into the H-B equation, you find out pretty quickly that during two-a-days this lineman probably needs about 5,000 calories (well, technically “kilocalories”) a day to maintain his playing weight, with variations depending on his muscle mass and how active he is during the sessions.  That’s about twice what an average American man needs during the day.

To put the amount of food in 5,000 calories in perspective:

  • At McDonald’s, a large quarter-pounder with cheese combo tops out at 1,510 calories.
  • A large Supreme pan pizza at Pizza Hut has about 3,300 calories.
  • KFC’s Double Down sandwich has a measly 600 calories.
  • The Cheesecake Factory’s Bistro Shrimp Pasta (recently named by Men’s Health as “the worst food in America”) boasts 2,730 calories.

Put another way, a typical male would approach this expenditure during a day-long hike while bearing a loaded backpack.  So 5,000 calories is a lot of food.  How do these guys get through August without shrinking?  The short answer is that many don’t.  Staving off dehydration means keeping the gut constantly full of water (not food), and exercise-induced fatigue can dull the appetite.  And of course, constant practices make it hard to fit in meals.

The biggest tool in keeping the weight on is an American icon: the all-you-can-eat buffet.  They’re staples at colleges across the country and critical for players needing to add some pounds.  Even the power of fast-food joints and Chinese-American restaurants pale in comparison, as dining out regularly is beyond the budgets of most students.  On-campus, though, players can cram in two or three buffet trips a day and supplement with snacks as needed.

Not that mindless gorging is advisable.  A binge followed by a long fast might not actually bump a player’s calories enough to stave off lost muscle, while too much face-stuffing leads to fat, winded players who aren’t much good on the field.  Getting in enough nutrients (especially protein) is also critical, but fruits, vegetables, and lean meats fill you up without having as much caloric density as fats and carbs, so things are further complicated.  This need for intelligent balance is why nutrition coaches have become so important at the college and pro levels (more so at universities—pro players have the financial means to hire personal dietitians.)

In its own way something as mundane as keeping weight can be an impressive and even clinical undertaking. In my experience, the only athletes who manage to outdo football players at this game of calculated overconsumption are powerlifters either seeking to move up in weight class, or competing in the heaviest weight divisions.  If you’d like to learn about some of the extreme measures used in the PL culture, or take a slightly more technical look at how athletes manage their energy intake, check out my article on the subject at:


The NFL’s Ban on Crown-of-Helmet Hits

The NFL’s new rule prohibiting some hits with the crown of the helmet is being called ‘controversial’ in almost every news piece it appears in, to the point where it’s drowning out another new protective measure to eliminate peel-back blocks. Marshall Faulk has been particularly vocal, calling the ruling “crazy” and “stupid,” and citing head-up/face-up hits as causes of injury, including the concussion Steven Ridley incurred from Bernard Pollard during last year’s AFC championship game. I’m in the camp that believes the head-up rule is one that’s going to make football a slightly safer sport for a variety of reasons without drastically changing the game.

The instant of collision between Steven Ridley and Bernard Pollard; notice a slight flaw in Faulk's reasoning.

It’s a foregone conclusion that our bodies never evolved to endure head impacts. The position where the spinal column can best absorb force (a neutral posture that results in crown-first hits in football) is the weakest position for the neck muscles. Our large, thin skulls aren’t dense enough to withstand severe trauma, nor are they faceted to deflect blows. Finally, the brain itself is structurally fragile and anchored in only one location, which means it can twist and actually bounce against the skull during external impact; it’s suspected the gyri and sulci (the “wrinkles” in the brain) evolved to limit the amount of brain surface exposed to contact during head trauma, but even if true it’s a bit like saying your skeleton protects you from gunfire–it’s true, but not very practical.

The fragility of the skull and the attached sensory organs led us to adopt protective behaviors to keep us safe. Almost paradoxically, protective helmets and pads put athletes at risk by nullifying these behaviors. The advent of contact sports—especially collision sports with hard helmets—runs counter to these behaviors. In football, the head and face are protected from the superficial wounds that would otherwise accrue with repeated blows. Without a helmet, concussion-inducing hits would lead to deep lacerations, fractured bones, broken teeth, displaced eyes, and other injuries that prevent subsequent immediate hits and deter future activities of the kind.

With the helmet, only the brain is unprotected, and its ability to send damage-indicating sensory signals is limited. Unlike a sensitive piece of anatomy such as the nose or lips, the brain has no sensors for detecting damage to itself—put simply, it can’t feel pain in the normal sense. This is great for doctors, who can perform brain procedures with only local anesthetics, but not so much for gauging our own head trauma. If we felt neurons tearing or being battered during a punch the same way we’d feel our nose breaking or lip splitting, football would be a very different game. Football isn’t the only sport to fall victim here. Boxing does much the same thanks to gloves and tape, which both limit superficial facial injuries and protect the bones in the hands, while allowing tremendous amounts of force to impact opponents’ heads.

Head-up hitting can help alleviate some of these factors. First, there are behavioral aspects. Face-up hitters are more likely to move under control and at slower speeds, which limits the force being applied to the head. They also tend to position themselves in a way that avoids a head-on collision. Part of this is an instinctual desire to protect the face, which can steer players towards more shoulder-to-shoulder hits. It’s also tactical in that a player with his head up, eyes open, and moving at a controlled speed is better able to avoid or deflect contact (in the case of breaking tackles and shedding blocks) or to make plays that might lead to better on-field results than a hard hit (such as a form tackle, play on a ball, or proper stalk block.)

There are also mechanical advantages to head-up hitting. I mentioned earlier the weak muscle position of the crown-first hit. This is because a neutral head position requires the muscles of the neck to work in balance with each other in a relatively loose manner while the spine is largely responsible for positioning. In this situation, there is little way for force to be dispersed from receiving angled hits; neither the brain nor spine is aligned to counter them, and by the time the muscles react to counter the blow, it’s already come and gone. This is part of why earhole hits can so often lead to concussions: the head not only takes the initial blow, but the neck muscles can’t react quickly enough to prevent rebound trauma caused by the head whipping around like a speed bag.

Head-up hitting, on the other hand, locks the head both at the end of its ability to extend and butts the base of the helmet against the shoulder pads and neck rolls/collars. There’s a slight measure of absorptive give (which might be helpful), but for the head to significantly whip backwards on impact the entire body essentially has to move along with it, thus offering much more protection from whipping. Head-up hitting also actively and dominantly engages the upper portion of the trapezius muscles and other thick neck extensors, which are the strongest muscles in the neck. Rather than being in a reactive balancing act with weaker flexors, the upper traps and extensors are already tensed against blows before contact is even made, which reduces extra motion in both axes.

Trapezius highlighted in red; note the size compared to other muscles attached to the neck and skull.

Looking back, Faulk’s argument about the Ridley/Pollard hit is specious—Ridley actually lowered his head to use the crown of his helmet against Pollard’s earhole, despite being in a fairly upright position. In doing so, he negated the absorptive ability of his body and relied on the weaker muscles of the neck. Essentially he contorted himself into a poor position. Had he kept his head back, there may have been only a glancing blow between helmets, with most of the impact occurring at the shoulders (which ended up happening during the hit, anyways) and he may have been able to better absorb force from the hit, though it’s not guaranteed as I’ll note below. Pollard is in a vulnerable position, too, though because he’s tensed and aligned as a result of essentially looking up at Ridley just before impact, he’s better protected.

Is the head-up hit a solution to football concussions?  Not at all. It’s really only applicable to players in the secondary, and not to QBs or linemen. In terms of the hits the rule is designed to soften, the trapezius is strong, but not strong enough to consistently overcome the force of angled linebackers or arcing receivers. Given that leading with the crown also has an instinctual element in that it can protect the face during impacts, it’s going to be tough to teach: we might see a ton of minor face-up collisions while the big hits still turn into crown-first blows.

Even straight ahead collisions like the back-on-backer hits the rule seems to target are going to still cause concussions.  Head-up hit forces created by football players at any level can lead to brain injury, and the sport is far too chaotic to guarantee only stable, evenly-matched hits. Referring again to the Ridley/Pollard hit, where Ridley likely lowered his head without thinking of the act, there’s also no good protective strategy for an upright player or someone in mid-stride/mid-leap. It’s extremely difficult for even a fully-readied player to overcome a mid-air hit followed by a slam to the ground. Even if someone in Ridley’s situation avoids the frontal tackler or limits initial contact, players coming in from the sides are still major threats, too.

And for Ridley specifically, his chin would have been exposed during the play had he not lowered his head. Crown-on-chin blows are like uppercuts from sledgehammers, and it’s tough to imagine a player not only giving away his chin, but doing so on faith that a defender won’t hit it.  Airborne and upright hits are just damned-if-you-do/damned-if-you-don’t situations where avoiding them is the only safe measure.

There’s also a devil in the rule’s details: leading with the crown is only banned outside of the tackle box, meaning short interior runs and blocks will probably still resemble a documentary on bighorn sheep.  More generally, if repeated subconcussive blows lead to the chronic problems that some suspect (or are a greater problem than occasional concussions), a head-up tackle rule only masks the real problem. In the final measure, the rule will likely help the immediate health of players by turning some hard crown hits into wrap tackles. But ascribing anything more than that is a stretch.

How Mike Mamula Crashed the Combine

Fairly or unfairly, Mike Mamula is remembered as the guy who exploded our perception of the NFL Scouting Combine.  His performance (which today might be considered routine) was so phenomenal that it may have advanced the Boston College DE’s landing place in the 1995 NFL Draft by several rounds.

Coach Mike Boyle.

There’s some conflicting background on whether BC strength and conditioning coach Jerry Palmieri (now with the New York Giants) or another local S&C coach, Mike Boyle, were more influential.  Both are excellent coaches who no doubt had major roles in Mamula’s performance; it seems most likely that Boyle was responsible for Mamula’s gaudiest performances, since that degree of specialized training would fall outside the range of normal activities for a college S&C coach.  Boyle is credited by some as the inventor of combine training, which lends more weight to this theory.

Boyle’s background in both powerlifting and athletic training informs his methods, and over the years he’s worked for most of the major sporting organizations in the Boston area, including the Bruins, Red Sox, and Boston University, moving from full-time jobs to consulting roles that supplement the much more stable and lucrative profession of running major training facilities.  These days he’s a known-enough figure in the S&C world to where his opinions are news makers; his argument against bilateral lower-body strength-training movements (especially the squat) kicked off a long-running debate not too long ago.

The set-up for Mike Mamula was perfect.  First of all, despite his post-NFL reputation, Mamula was a good player who’d been noticed by scouts. The LB/DE ‘tweener followed a solid junior year by capping his college career with an explosive senior season aided by BC’s switch to a 4-3 front, finishing with 13 regular-season sacks, an All-Big East nod at defensive end, and a four-sack bowl game.  Though not ranked highly at the time, he had the stats and situation that would corroborate a strong combine performance.  You can imagine a coach saying, “Well, if he’d played for a higher-profile school and had been in a defense that fit his skills, he’d be on everyone’s radar.”  In retrospect, it was also a weak class for defensive linemen, with only a few name players to come out that year.

That same hypothetical coach could also have said, “And he probably wasn’t coached well, either.”  It’s a common line of reasoning in the NFL, born of a big-brother mentality the league carries.  Some of it’s reasonable—get a guy full-time and with a paycheck on the line, and he might be a little more motivated than he was in college.  Other times, though, it’s simple arrogance.  Add to this that the 90’s were a renaissance for the 4-3 defense where speed became paramount, and the league would be easily excited by an athletic pass rusher.

The final ingredient was the insertion of a savvy coach into a combine milieu that was old-fashioned at best.  The NFL Scouting Combine was about a decade old in 1995, and was still seen more as a replacement for in-person visits to the Senior Bowl and private invites to NFL facilities.  It was about watching routes, releases, and footwork, and about interviews and giving players the eyeball test.  Not as appreciated was the fact that the combine was the only way of creating an even playing field for comparing athletic talents of so many players.  Rather than looking hard at what drills meant, they were treated as a “pass-fail” series of tests…and the players knew it.  In fact, the entire football system—from high school to the pros—was largely in an anachronistic mindset when it came to valuing strength and conditioning: it was assumed talents of speed and strength were largely uninfluenced by training.

Boyle’s strategy seems so simple that today it’s almost hard to believe he made people rethink the combine: he focused Mamula on the gaudiest raw-athleticism events (vertical jump, 40-yard dash, and bench press, in particular), and then trained him to be good at the events.  If Mamula could stand among his peers, coaches would reevaluate his film and see him not as someone taking advantage of weak competition in low-stakes games, but as a hidden gem.

The catch is that all the tests had little do with success on the football field.  The bench press test is the most egregious example: for a 400 or 500-pound bencher (which is common for college linemen), the combine bench test is an endurance event akin to judging a sprinter based on his 5k speed.  Players have to pace themselves, build-up tolerance to pain and fatigue, and learn techniques to make the motion as easier as possible.  Being overweight and having short arms is essential to a great bench performance; neither characteristic is exactly desired on the field.  And as you’d expect, most of the techniques for excelling at the bench press test have limited usefulness in improving football performance, and push the rules of the combine to their limits.

The strategy worked.  Mamula ran a 4.58 40, hit 28 repetitions on the 225-pound bench press tests, and had a 38.5” vertical jump.  He was faster than linebackers, had better jumping abilities than some corners, and out-benched much bigger offensive and defensive linemen.  It was an eye-catching performance.  When the Eagles selected him with the 7th overall pick, Hugh Douglas and Warren Sapp were still on the board.  In fact, Head Coach Ray Rhodes and company traded picks with Tampa Bay in order to move up and get Mamula.

Philadelphia got themselves a decent player, a solid guy who never cracked double-digit sacks in a season (but came close) and who struggled with injuries.  Some argue that starting three years for a top-shelf Eagles defense speaks to his abilities, though I feel it speaks more to the money invested in him.  I remember him getting engulfed by bigger tackles, especially when rushing the passer.  He never looked agile enough, either, to make the transition to 4-3 ‘backer, which might’ve extended his career (though it’s a very rare transition for the NFL.)  He was out of the league by 2000.  While it certainly wasn’t the career expected of a single-digit first-rounder, he wasn’t a Ryan Leaf, either.

Meanwhile, Warren Sapp and Hugh Douglas became forces on the field.  Despite his gifts, Sapp had a reputation as a wild card from his days with the Hurricanes, so the Eagles might be forgiven for missing a player who would’ve been a perfect fit for their system.  The Bucs took the risk, and ended up getting him and Derrick Brooks, the two players who would become the cogs of their dominating defense.  Missing Hugh Douglas was more of a head-slapper, at least in hindsight.  While he was drafted by the Jets, they ended up trading him for draft picks a few years later…to the Eagles.  He earned a few All Pro nods in Philadelphia, and helped provide the pass rush they never got from Mamula.

Out of all the parties in the Mike Mamula story, Mike Boyle probably came out best.  He’s an S&C star who’s regularly lauded in mainstream news, sports, and health publications.  While he opened the floodgates for combine prep, he managed to stay ahead of (or at least with) the leading wave.  And he’ll forever be remembered as a sort of gym-rat jester who pantsed the NFL at their own event.

Remembering the Immaculate Reception

Pittsburgh's Franco Harris wards off Raiders DB Jimmy Warren on his way to the endzone.
Called by some the greatest play in the history of the NFL, the Immaculate Reception is nearing its 40th anniversary.  While Franco Harris’ improbable touchdown catch had no major impact on the playoffs that year (the Steelers later lost to Shula’s perfect Dolphins in the AFC championship), it was the highlight of a game that signaled the start of four consecutive playoff matches between the two teams, and in retrospect heralded the imminent Steeler’s dynasty.  Forty years later, the play still stands as one of the most dramatic moments in American sports.

It was an exciting play by anyone’s standards, especially for television audiences.  The game was already a classic 7-6 slugfest featuring John Madden and Chuck Noll on the sidelines, and Terry Bradshaw, Kenny Stabler, George Blanda, Fred Biletnikoff, Art Shell, Gene Upshaw, Joe Greene, Jim Otto, Jack Ham, and Mel Blount on the field.  It was 4th and 10, 22 seconds left on the clock, with the Steelers down by a single point and stalling on their own 40 yard line.  Folks at home saw Terry Bradshaw elude two rushers and heave a desperation pass to John “Frenchy” Fuqua, only to have feared-hitter Jack Tatum level the intended receiver.  The ball was knocked out of view.

Then Harris flashed into the frame, a defender trailing him.  He had made a shoestring catch of the deflection and was running down the sideline.  The only player capable of stopping him–Jimmy Warren–was caught so off-guard that he was two steps late in taking what would’ve been a makeable tackling angle.  Harris stiff-armed Warren and stepped into the endzone to win the game.

The play’s controversy came from a now-stricken rule: at the time, receivers couldn’t catch mid-air balls that had deflected off a teammate.  If the ball had touched Fuqua before Harris’ catch, the play would be dead by rule; if it had instead bounced off Tatum, it would’ve been a live ball.  The refs ruled on the side of the Steelers and history was made.

Not surprisingly, there’s debate to this day as to who the ball actually hit.  A woozy Fuqua told listeners after the game that the ball had struck his chest.  John Madden says he still can’t figure out what happened, and has sworn off making comments about the play.  While today’s high-speed/hi-def cameras and instant replay might’ve made a conclusive statement, the grainy footage of yesteryear doesn’t clearly show who caused the deflection, and never shows if Harris caught the ball without it touching the turf.  Some have likened NBC’s footage of the play to a sports version of the Zapruder film.

The deflection has been the biggest source of contention–not even the Raiders argue much that Harris failed to make a clean catch.  The clearest indicator of who caused the deflection is the speed at which the ball bounced away.  Carnegie Mellon physicist John Fetkovich determined that only Tatum, who was rushing full-speed towards the in-flight ball, could’ve deflected it so forcefully.  That’s good enough for me, though I imagine even decades after the fact more than a few Raiders fans unconvinced.

Give the Finger, or Save It?

If there was an award for “Most Valuable NFL Receiver of the Past Few Weeks,” Dallas’ Dez Bryant would probably win it.  His touchdown catch versus the Steelers this weekend helped add a fifth win to the Cowboys’ recent 4-1 run and kept the team’s playoffs chances viable.
A pre-injury Dez Bryant warming up; image courtesy

Bryant’s done this with a broken index finger on his left hand.  Even though the finger needs surgery to heal, he’s stated his intent to play until the Cowboys’ season is over.  He played the Pittsburgh game with a splint that he’ll wear until the operation date.  More than one media outlet has praised Bryant for this decision, calling his choice to play through the injury a sign of maturity from a volatile player. They say he’s learning from his teammates, who’ve played through torn spleens and punctured lungs.

That said, their declaration might be mistaken.  Bryant could be sacrificing an irretrievable measure of talent just to help an inconsistent and injury-riddled squad, one that seems as likely to lose the remainder of its schedule as it is to win it.  To put things another way, the Cowboys aren’t going to win a Super Bowl this year because the “Mayan Apocalypse” will happen first.

Make no mistake about it: football is hell on fingers.  They get caught in jerseys and facemasks.  They get cleated.  They take crown shots from helmets.  They get pinched and sometimes the skin “de-gloves,” which is exactly what it sounds like.  They get cut and slashed over and over until the scabs finally have time to settle into mottled scars.  They get twisted and bent backwards beneath piles.  It can be unpleasant.  Ask Anthony Munoz, Brian Baldinger, or Torry Holt.  Or if you can’t, let them show you:

Anthony Munoz


Brian Baldinger


Torry Holt.
Damage the tendons, ligaments and joint surfaces enough, and eventually those fingers will stop popping back in place and start sticking out sideways.  Along the way, you can get arthritis and bone cysts, among other pleasant side effects.

The most famous situation is the tale of 49ers’ safety Ronnie Lott, who in 1985 shattered the tip of his pinky finger while making a tackle.  His options were to get a bone graft to repair the finger (and miss the post-season) or to get a third of the ragged digit amputated (and miss part of his finger.)  Lott went with the amputation and added more mystique to his Hall-of-Fame career.

Football is hell on fingers, and more often than not, injured ones just get in the way.  Willie Young, a current defensive end for the Detroit Lions, thought seriously about amputating part of his middle finger.  Heck, a few years ago an o-lineman for D-II Mesa State College (now Colorado Mesa University) opted to have a dislocated pinky removed rather than wait for it to heal.  Football isn’t unique, by the way.  It happens in rugby, mixed martial arts, and other sports, too, with non-essential fingers and toes ending up on the chopping block.

Notice that I didn’t mention basketball players.  While they probably get more jammed fingers than anyone (including nasty avulsion injuries where tendons tear and take pieces of bone with them), their hands are so important that protecting them is a must.  The same is true for wide receivers.  A working index finger is essential to excelling as a wide receiver, and by forgoing surgery Bryant may be hurting his career down the road.  Doctors have warned him that his finger could stiffen without surgery.  That may not sound like much–I imagine plenty of readers would trade their back, hip, knee, or shoulder problems for an uncooperative digit–though when it comes to handling a football, the index fingers are critical.

The index finger is the key finger for securing the football when a player’s running down the field.  It hooks over the end and helps pin the ball against the runner’s forearm and upper arm.  Hooking prevents defenders from grabbing the tip and ripping it out, while pinning keeps swats and punches from dislodging the ball. If the finger can’t contract against the ball then it’s useless on either account.  Probably more important to Bryant, though, is that the index fingers are the first to make contact with the ball on any passes caught while facing the quarterback.  That’s about 90% of the passing tree.  If that finger doesn’t give or flex like it needs to, it could pretty much act like a pinball flipper and knock passes away.

A semi-functional finger might not be a big deal when he’s open and gets a lob to the chest (like his touchdown catch this weekend), but it could become a very big deal when he’s covered in defenders and has a spiral screaming in on him.  And any lingering health issue he develops now is going to loom larger later in his career when he’s slower and can’t beat guys one-on-one like he used to, or pull away from guys who are trying to tomahawk a fumble.

My thought is that he’ll be okay.  He hasn’t fully tapped his talents, the season will end more quickly than America’s Team hopes for, and Bryant will have surgery before he ends up with an arthritic club on the end of his hand.  He also plays for a team with plenty of weapons on offense, so he won’t find himself put in positions that play against the injury.  If anything, Bryant’s career probably rests more on this assumption that he’s grown up in the last few weeks.  That, and the blessing of fortune every football player needs in order to avoid career-ending injuries and the pitfalls of fame and wealth.

Concussions and Youth Football

Over the past month, I’ve reported on several lectures given by prominent concussion researchers; you can read my earlier pieces on these sessions here:

Part 1:

Part 2:

The most recent lecture focused on youth concussions, and was given by Dr. Mariecken Fowler, a prominent neurologist, researcher, and regional resource on concussions in western Virginia.  This final piece addresses Dr. Fowler’s points along with all the youth-focused topics that came-up during prior presentations.

Helmet Research and Concussion Prevention

Let’s return to Dr. Stefan Duma’s helmet research at the Virginia Tech-Wake Forest Center for Injury Biomechanics (CIB).  In addition to studying college players, Duma has also studied helmet impacts with a local youth team.  Seven players (aged 7-8) were monitored through the course of the season.  While the number of subjects monitored is low (and the results confined to one team), the findings are worth knowing, and will likely be corroborated as the number of youth teams monitored increases.  First, the VT team recorded several instances of high acceleration that came disturbingly close to approaching the levels obtained by college players.  This is possible because, while the youth players don’t reach the speeds of higher-level squads, they have far less muscle mass and control to dampen impact acceleration.  Several of the high-g tackles Duma showed involved the players getting tackled from the side or behind.  The acceleration came from the players’ heads shaking, to use Duma’s phrase, like bobble-head dolls.

Picture of the youth football team monitored by Virginia Tech researchers, with insets showing the custom-built Six Degrees of Freedom accelerometer system (photo courtesy Virginia Tech.)

Second, the youth players received more head impacts than expected.  Why?  Because youth players not only act like bobble-head dolls, but they’re roughly built like them.  Children have proportionally larger heads than adults, and their helmets are built to adult proportions, which makes them even larger targets and harder to keep stable.  Essentially, the helmets occupy so much space that it’s difficult for a child to tackle or block without a helmet strike (which is usually helmet-to-helmet) and difficult to control the extra helmet mass when it’s in motion.

Third, the head impacts—especially hard ones—occurred mostly during practice.  The paper published from this research noted that 76% of +40g hits and 100% of +80g hits were practice hits; these hits generally also involved the higher levels of rotational acceleration Duma’s team found.  Even when comparing a single average practice to a single average game, 15% more head hits occurred during an average practice.  This is in distinct contrast to high school, college, and pro football, where the worst hits occur on gameday, and reflects the play style of youth leagues.  Youth football games involve lots of lateral movement and angle tackling, and relatively few “lined-up” hits made with a full head of steam.  Practice drills, though, frequently involve running-start tackling and blocking drills that produce greater impact speeds.  A related trend is the greater percentage of hits to the side of the head relative to higher levels of play.  This is largely due to the prominence of angled tackles into the sides of players; these hits also increase the likelihood of a tackled player bouncing the side of his head against the ground at the end of the tackle.

The CIB team and observers from other schools offer some guidelines for limiting hard hits in youth football:

  • Make sure helmets are properly inflated so that they can effectively distribute impacts.
  • Teach head-up hitting on offense and defense, which places the head in a strong position and limits movement during collisions.
  • Reduce full-speed, running-start tackling and shedding drills—particularly head-on drills—during practice, and instead focus on slower, single-player drills that reinforce fundamentals.

I’d hypothesize that bracing and controlled tumbles might improve players’ abilities to counteract head forces, though there’s no evidence to back this up (it may very well be that youth players don’t have the proprioceptive development to benefit from such drills.)

One more point comes from UNC’s Kevin Guskiewicz, who conducts helmet research and advises the NFL.  He comments that preventing children from playing youth leagues may set them up for greater risk if they play on varsity and junior varsity football teams later in life.  This is because inexperienced players lack tensing and safety skills that are developed in youth football.

When Prevention Isn’t Enough

When concussions happen, immediate recognition is essential.  This isn’t possible without a safety-minded approach.  Coaches, parents, and attending medical professionals should investigate big hits and hits that involve players’ heads whipping or rapidly rotating.  A player who’s gotten his or her “bell rung” has had a minor concussion, so make sure you take kids through an appropriate concussion questionnaire after big hits.  To make sure these steps happen, all coaches should be educated on concussions, even if a medical professional is available.  Though this isn’t a replacement for a thorough training series on concussions, the CDC recommends coaches to suspect a player of having a concussion if the child:

  • Appears dazed or stunned
  • Is confused about assignment or position
  • Forgets an instruction
  • Is unsure of game, score, or opponent
  • Moves clumsily
  • Answers questions slowly
  • Loses consciousness (even briefly)
  • Shows mood, behavior, or personality changes
  • Can’t recall events prior to hit or fall
  • Can’t recall events after hit or fall

If it seems a concussion has occurred, pull the player from the practice or game, and find a calm location to place them until they can be taken to a doctor.  If a parent isn’t on-hand, the child should be supervised by a medical staffer or coach until the parent can arrive.  Follow-up care is critical; Dr. Mariecken Fowler of Winchester Neurological Consultants notes that problems can arise when children are evaluated and cleared to play by doctors unfamiliar with concussions (included were troubling incidents involving fringe specialists clearing children far too early.)  It’s also routine now for victims of head injuries to receive precautionary scans to rule-out undetected vascular issues that could arise from trauma.

If you’re a parent and notice acute headaches, nausea, irritability, or mood swings that occur unexpectedly after a practice or a game, you may be witnessing the effects of a concussion.  These symptoms may arise days after the responsible blow; latent symptoms are triggered by things like intense thought (e.g., while taking a test), stress, or physical activity.  Since there are severe, evidence-backed risks involving repeated head blows following a concussion, it’s imperative to make sure your children receive medical attention after a suspected undiagnosed concussion.  This best-known example of this is the case of Zackery Lystedt, a middle school player who received multiple hits during a single game that had him fading in-and-out of a coma for three months, and left him severely disabled.  It’s an extreme example, but illustrates what can happen when mild trauma is worsened by additional damage.

Following the occurrence of a concussion (or likely occurrence of one), the affected child must be rested.  No physical or mental stress can be allowed.  Individuals under the age of 21 are most susceptible to problems with repeated head trauma.  Dr. Fowler notes that sleeping and watching television are two of the safest activities possible.  Sleeping in particular promotes recovery; unfortunately, insomnia can be a side-effect of concussions, which may warrant the use of sedatives.  Concussions may also magnify (or even trigger) depression and impulsive decisions, so it’s probably advisable for parents to monitor their children and keep them out of stimulating environments.   Fowler emphasized this point when recounting the story of a teen who committed suicide while staying active within a few days of receiving a concussion.  While an anecdotal case, the teen’s history was free of mental illness symptoms or prior stressors other than the concussion, which hints strongly that the injury was related to his death.

Fortunately, technology is helping improve concussion diagnoses.  A software suite of note is ImPACT (IMmediate Post-concussion Assessment and Cognitive Testing).  You can think of ImPACT as a computerized combination of quizzes and rudimentary video games.  Athletes using ImPACT participate in a pre-season session with the program where they complete a battery of memory and reaction tests.  These pre-season tests serve as baseline measurements.  When players are later suspected of having had a concussion, they are run through the test again; if the second batch of results shows significantly worse brain function, it’s highly likely the athlete has sustained a concussion.  Follow-up tests are administered, and when results have returned to baseline, the player is cleared for a return to sport.

ImPACT isn’t perfect.  It first requires recognition of a concussion or preemptive action on a threatening hit.  There is also chance that intentional “sandbagging” during baseline testing can throw-off later results, though the depth of the test and the player’s inability to know the metrics and scoring probably nullify this aspect.  The biggest limitation by far, though, is cost.  Organizations such as the NFL and Dick’s Sporting Goods have helped pay for youth football safety measures; Fowler remarked that in her geographical area in northwestern Virginia the largest regional healthcare provider agreed to purchase a license and a number of uses (ImPACT works on a pay-per-test model) after a bit of lobbying by concerned locals.  My recommendation is that working with public health systems (or badgering/guilting them into helping) is probably the approach with the greatest chances of success.

Much like imaging diagnostics are improving to the point where we may be able to catch CTE in living subjects, they are also improving in concussion detection.  Fowler believes an MRI technique called Diffusion Tensor Imaging may be able to exactly diagnose concussions in the near future.  Of course, this will be cost-hobbled as well due to the expense of MRI machinery, though not in a way easily impacted by worried parents (unless some of those parents are philanthropic millionaires.)

For more information, the CDC provides a thorough, sport-focused look at concussions:

USA Football is a good resource for football-specific information:

Helmet Research at Virginia Tech

Note: This piece follows-up on my earlier overview of concussion research:

The Virginia Tech-Wake Forest Center for Injury Biomechanics (CIB) is one of the most impressive injury research institutions around.  While it’s best known for studies performed by the Virginia Tech branch on football helmets, the Center is a diverse operation.  The bulk of the VT head injury office’s floor-space is actually devoted to classified military research, mainly related to vehicle crashes and IED impacts.  The institute also studies the safety of civilian vehicles in crashes and the safety of children’s toys; the Wake Forest portion conducts a great deal of automotive work.

The CIB operates from within the VT-WF School of Biomedical Engineering and Sciences.  Running the school is Dr. Stefan Duma, who also happens to be the man responsible for kick-starting modern helmet research and making it a topic of public interest.  Duma has co-authored hundreds of papers on impact injuries; his work has lately included research on head impacts in baseball players, how organs are affected by crashes, and how vehicle-related impacts affect pregnant women.  Duma has also been the key force behind the rapid growth and rising prominence of biomedical engineering at VT.

Almost all of his head-safety projects (as well as those of the faculty, staff, and students beneath him) are funded either by the National Institutes of Health, which is a federal organization that awards research grants to promising health projects, or the Department of Defense.  The Center for Injury Biomechanics takes no money from the companies whose products are researched; even speaking fees are donated to youth football programs for the purpose of buying safer helmets.

Monitoring Player Impacts

Virginia Tech’s work in the field of helmet safety can be broken into two parts—lab experiments and fieldwork.  The fieldwork ramped-up shortly after Duma’s arrival in 2000.  Since there was little data on what happened on the college football field with regard to helmet impacts, that was where work needed to start.  The first major step was outfitting 38 Hokies with HITS, or Head Impact Telemetry System, which is an electronics suite manufactured by Simbex.

Helmet Impact Telemetry System; the piece at lower-left is the helmet sensor suite.  Image courtesy Simbex.

HITS includes both computerized impact-reporting devices consisting of helmet sensors and the sideline computers that monitor the helmet sensors.  The helmet sensors are simple accelerometers that measure linear and rotational impacts.  They’re housed in a flexible plastic strip that also contains a battery and WiFi transmitter.  The strip mounts inside a player’s helmet, where it fits between the side and crown cushions.

The collected data is wirelessly transmitted to a laptop computer on the sideline where it’s not only stored for later analysis, but also used for real-time monitoring of how hard (and where on their heads) players are getting hit.  You’ll see images and TV footage of the computer being carted around inside a formidable looking crate packed with black egg crate cushioning (included in the image above), and you’ll also see all of it–computers and carrying crate–contained within a clear, rainproof plastic housing that looks like it could double as protection for the Pope.  HITS also includes pagers that medical staff can wear to receive instant alerts on high-g impacts.

The entire VT team is being monitored by HITS, as are the teams for several other schools.  This means nearly every single hit experienced by thousands of players across the country has been pooled and analyzed.  The upshot is that undiagnosed concussions have been greatly reduced in teams using the equipment, perhaps to the point of being eliminated.

In my previous post I mentioned how a Tech player stayed on the field after receiving a concussion.  The player was Brandon Manning in 2003; despite the concussion, he not only stayed on the field but led the Hokies with 16 tackles in the game.  Since Manning stayed in the game, the concussion went unnoticed by trainers. Manning himself didn’t think enough of the hit to report it.

Thanks to HITS, Tech researchers/trainers are now notified immediately when any player’s head receives an impact acceleration at or near concussion-levels.  When this happens, the player is immediately pulled from the practice or game for an evaluation—the system is even fast enough to routinely have players pulled from the field between plays.  Its main limitation is signal problems encountered by players at the edges of the endzone.

Testing Helmets in the Lab

When enough impact data was collected, it was time to test helmets in the lab.  This required that many varieties of adult football helmets be subjected to controlled impact testing.  As the picture below shows, the process isn’t too different from using a crash test dummy in a car.  The testing device is called a drop tower, and consists of a dummy head fixed to a vertical frame, which itself is fixed to an impact platform.  Helmets (without facemasks) are fixed to the dummy head and dropped from various heights and with various parts of the helmet shell hitting the platform.

Drop tower prior to helmet-mounting; standing at right is Stefan Duma. Image courtesy Virginia Tech.

The ability of the helmets to dampen various blows is measured and applied to probability data collected from the thousands of actual impacts recorded in on-the-field testing.  This mix of helmet resilience and risk data is called STAR, or Summation of Tests for the Analysis of Risk.  Fittingly, the helmets are judged on a “star” scale, with 5-star helmets providing the most protection against severe acceleration, and helmets with fewer stars performing less-well as the stars are reduced.

The results of these tests are made publicly available at  The first batch of results ran counter to the expectations of some, particularly in terms of helmet cost and intent.  First, higher cost didn’t necessarily correlate to greater impact reduction—several 4-star helmets cost less than a similarly priced helmet that was demonstrated to be the worst tested.  Second, as a few coaches at the Duma presentation I attended noted, several helmets marketed at skill positions showed better safety performance measures than some helmets marketed for use by players in the box.

Research Limitations

There are some limitations to what the CIB is doing with researching helmet safety and concussions.  Their goal is reducing high-risk head collisions either by improving helmet safety or reducing practices that lead to high-risk head collisions.  It’s important to realize that their work is informed by well-documented research on acute brain injuries.  While they’re certainly creating data that’ll be useful in measuring long-term health outcomes of concussions, we don’t have enough information to really understand the risk factors.  The CIB researchers also aren’t in the position of commenting on the long-term effect of sub-concussive impacts.  That’s the realm of epidemiologists and clinical neurologists, not biomechanics and engineering folks.  I think the smart money is that the CIB’s work is going to improve long-term outcomes for football players across the country, but that’s still far from proven.

More specifically, we have to understand that the end result of their work will not be a concussion-proof helmet.  Creating a helmet that would allow for the game to continue being played as-is while also being impervious to concussions is beyond our current technology.  The CIB’s helmet safety guidelines are creating helmets that are better at distributing impact energy, which will reduce head acceleration in properly tensed and positioned players.  Even the highest-rated helmet isn’t of much help in unexpected hits where there’s no muscular tension and skeletal alignment to resist impacts, or in angled hits that the human body has difficulty opposing.

Finally, the team is working on refining its testing methods.  They plan to further investigate the ability of helmets to reduce rotational forces, to test helmet differences at varying temperatures that might alter the properties of the helmet shell and cushion, and possibly to include tests with facemasks.  I doubt any of these refinements would significantly change STAR results–the variables have a measure of theoretical and statistical predictability–though more data is never a bad thing.

Looking Ahead

Because I thought it deserved its own space, I’ll talk about VT’s youth football research (and youth safety issues in general) in a later post.

What We Know (and Don’t Know) About Football and Brain Injury

With the recent deaths of Ray Easterling and Junior Seau, and the prominence of head-shots within the Saints bounty scandal, football-related brain injuries have returned to the news.  Unfortunately for the general public, these reports don’t contain much useful information on the injuries and their causes, diagnoses, and treatments.  Over the past few weeks, I’ve had the opportunity to listen  and speak to Dr. Stefan Duma of Virginia Tech and Dr. Jeffrey Barth of the University of Virginia, both of whom are leaders in the field of head injury research.  Duma leads the most sophisticated head injury research facility in the country, and also leads the program that monitors head impacts received by VT players during games and practices.  Barth is a member of the NFL Players Association Concussion Committee and co-wrote a study that first put concussions in the public spotlight back in the 80’s.

Comparison of healthy brain tissue to that of a football player and a boxer; slide courtesy J. Barth..

Though the media is focused on repeated blows to the head (and reasonably so), it’s important to note that a single concussion can be extremely harmful.   A concussion is an injury to the brain caused by sudden acceleration.  A common technical term for a concussion is “mild traumatic brain injury,” which highlights its potential seriousness.  Athletes in many sports often play through mild concussions; Dr. Duma showed one clip of a former Virginia Tech linebacker who suffered a concussion during a play, stayed on the field, and nearly started the next play lined-up at deep safety before a teammate redirected him back to the box.  This was in the early days of the program when guidelines were still being established; a player at VT (and other schools with helmet-safety programs) in this situation today wouldn’t return to the field.

Concussions can cause disorientation, nausea, head pain, light sensitivity, unconsciousness, insomnia, mood changes, and memory loss.  The acute effects of a concussion last on average between 5 and 10 days.  Longer-term symptoms generally clear within three months, though extreme examples can last for years.  Children generally take longer to recover.  The typical concussion occurs when the head experiences around 100 g-force of acceleration (or 100 times the acceleration of earth’s gravity).  As a comparison, an amateur boxer’s dominant-hand hook can create about 80 g of head acceleration.

An average player at Virginia Tech will have four incidents of  circa-100 g head acceleration every season.  Interestingly, out of the entire team only about four actual concussions are diagnosed annually, while the rest of VT athletics reports around 26 concussions during the same period.  This speaks to the variability of concussion susceptibility, and also to football players’ ability to tense their bodies in ways that dampen impact forces.  Additionally, Duma notes that his research has lead to VT and other schools to adopt safer helmets and reduce or eliminate drills that lead to excessive head impacts.  Barth noted that rather than follow his committee’s recommended practice guidelines (which would reduce helmeted practices by roughly three-fourths), the NFL ownership installed rules that halved helmeted practices.

Concussions occur because both the head and the brain are each flexibly tethered, and both can independently whip about on impact, causing the sudden acceleration and deceleration responsible for concussions.  We know this movement can actually rip apart the connective links of brain cells, though beyond that we’re less certain about what else happens within the brain during and after a concussion.  We do know that having one concussion increases your risk of having another by 3-to-6 times, though we aren’t sure if this means certain people are simply prone to concussions, or if having one concussion increases your sensitivity to future brain trauma.  This increased risk is especially important to know because having a second concussion (even a minor one) during the acute phase of a prior trauma can lead to serious complications.  The only proven form of concussion recovery is rest and time.

Getting more into the controversy of football and head injuries, we don’t know how to define or quantify the effects of repeated concussions or repeated sub-concussion blows to the head.  It seems that repeated blows can trigger chronic traumatic encephalopathy (CTE), which is a condition that causes both brain deterioration and the harmful accumulation of defective tau protein in the brain.  Symptoms of CTE include chronic and worsening dementia-like memory and cognition loss, as well as depression, aggression, loss of motor control, and disorientation/confusion.  The symptoms generally appear late in a player’s life, though tau deposits are now being found in the brains of middle-aged men, active NFL players, and even teenagers who’ve had multiple concussions.  Over a dozen former NFL/college players have been diagnosed, and if media reports are to be believed, Easterling and Seau both displayed behavioral symptoms consistent with CTE.  Compared to the entire league, this is still a very small sample, which makes it difficult to determine just how frequently CTE occurs.

At the moment, CTE can only be diagnosed by post-mortem examination of the brain.  The Boston Center for the Study of Traumatic Encephalopathy that’s frequently referenced in media reports is among the best known institutions performing these examinations, and has done so on the brains of several NFL players.  Dr. Barth notes that Siemens’ healthcare division claims to be 18 months away from deploying PET scan technology capable of detecting CTE in living patients; while PET equipment isn’t nearly as common in hospitals as MRI and CT equipment, it’s a step in the right direction.

Our limited understanding of the brain and impacts is very cloudy.  It may turn out that only a small, definable subset of the 5 million adults, teens, and children currently playing football will ever be at risk for severe and/or long-term brain injury.  Or it may turn out we’re experiencing a sport-related epidemic of lasting brain injury.  We just don’t know.  In this situation, knee-jerk fears can give rise to sham treatments and unwise practices, while apathy can dampen efforts to learn more and create healthier practices.  As Dr. Barth consistently reinforces, we need to be comfortable with the ambiguity of this subject while working towards resolving it.