More on the ALL ligament

Last week, I wrote about the discovery of a new ligament in the knee, the Anterolateral ligament (ALL).  This week I'm going to share my opinion on the ligament.  The first thing I thought when I read this, was "how did they just now discover this ligament?"  Doctors and scientists have been examining the human body, especially cadavers, for hundreds of years.  How could they just now discover a new ligament in the knee?  I'm not sure exactly what the answer to this question is.  Back in the late 1800s there was mention of this ligament, but nothing else came about until recently.  It could be that the location of the ligament made it difficult to find when examining the knee, or maybe it was mistaken for another structure.

Another important question is what is the clinical implication of this ligament?  Since it is on the anterior and lateral part of the knee, it would play a role in stabilizing the knee against anterior shear force.  An excessive amount of anterior shear force is a main mechanism for an ACL tear.  The ALL ligament might also be torn by this mechanism of injury, and since doctor's weren't aware of it's existence, it was not being repaired along with the ACL.  Thus, a person who sustained a tear of both the ACL and the ALL was only having one of the ligaments repaired, and therefore their knee was still somewhat unstable after surgery.  This is just a hypothesis, and much research and testing needs to be conducted to determine the exact clinical significance of the ALL ligament.

New Knee Ligament Discovery

Last month, surgeons in Belgium announced the discovery of a new knee ligament.  They are calling it the anterolateral ligament (ALL), and it is located on the anterior (front) and lateral (outside) part of the knee.  A French doctor in 1879 was the first to propose that there might be an additional ligament in the knee.  As you can see in the picture above, the ALL ligament starts in the same place as the LCL (lateral collateral ligament) on the lateral side of the femur, but it then runs more anteriorly and attaches to the tibia, where the LCL attaches to the fibula.  There are some questions surrounding the discovery, mainly, why did it take so long for this ligament to be found, and what does the ligament do?  Some people are even skeptical of the existence of the ligament.  I'll write again next week about my opinion of the ligament and what function it might serve.  This is a potentially big finding that may have implications for the future of knee surgery.

Fractured Clavicle

If you watched Monday Night Football, then you saw Green Bay Packers quarterback Aaron Rodgers leave the game after being hit and landing on his left elbow and shoulder (below).  The force from the ground (ground reaction force) caused Rodgers' clavicle (collarbone) to break.  With this mechanism of injury, the athlete will typically sustain either a clavicular fracture or a sprain of the acromioclavicular (where the clavicle articulates with the scapula) joint.  When Sam Bradford was playing college football at Oklahoma, he sustained two acromioclavicular joint sprains of his left shoulder with a similar mechanism as the one that injured Rodgers.  A fractured clavicle "normally" takes about 4-6 weeks to heal, but it could be faster or slower depending on the athlete and the type of fracture.  The athlete still has to be able to perform all the necessary movements before he or she is required to play.  The good news for Rodgers is that he broke the clavicle of his non-throwing shoulder, but this will still restrict his ability to throw a football while the injury heals.  He will likely miss at least 4 weeks of action, although it could be up to twice as long.

Unloading Reaction

We have been discussing in neural control the role of reflexes in the control of voluntary movement.  Yesterday we discussed a hypothesis that believes that reflexes play a very minor role in movement, and the central, voluntary commands sent from the brain control almost all aspects of voluntary movement.  There is a pretty cool reflex known as the unloading reaction that disproves this theory.

Imagine that you are holding a dumbbell in your right hand, and you are attempting to keep your elbow flexed (bent) at about 90 degrees.  You are instructed to continuously try and contract the elbow flexors (think biceps brachii, brachialis) in order to maintain this position, and you are instructed to continue to try and activate the muscles no matter what happens.  As you are holding the dumbbell, it is quickly removed from your hand.  What happens to the activity of the elbow flexors?

When the dumbbell is removed from your hand, there is a period of almost complete silence (no activity) in the elbow flexors.  Why does this occur even when you are trying to activate the elbow flexors?  When the dumbbell is in your hand, it activates the muscle spindles in the biceps (the dumbbell is trying to lengthen the biceps, which activates the muscle spindles), which causes a reflexive contraction of the biceps.  When the dumbbell is removed from your hand, muscle spindles are no longer activated, so there is no reflexive contraction of the elbow flexors.  This demonstrates that reflexes play more than a minor role in the control of voluntary movement.

Disturbing, but not surprising news

A recent report in the Chronicle of Higher Education talks about the difficulty that many athletic trainers face in dealing with injuries, particularly concussions, because they either report directly to the head coach or feel pressure from the coaching staff to return an athlete to play before he is ready.  I'm not going to comment extensively on this, but you can read another opinion here, and this link contains a good animation of the problem.  For full disclosure, I worked for one of the athletic trainers quoted in the first article when I was at Auburn.  There is definitely a clear conflict of interest between an athletic trainer and a head coach, especially in the ultra competitive world of NCAA football.  Most coaches have the best interest of the athletes in mind, but during the middle of a game, they cannot objectively decide if a player is able to return to a game, nor  are they trained to make this decision.  A head coach should also not evaluate the the skills of a medical professional.  Except for a few high schools games I covered, I never had to make the ultimate decision about rather or not a player can return to a game (that responsibility ultimately should rest with the team physician), but I can attest that the times I had to tell an assistant coach that one of their position players could not return to a game was not enjoyable.  Hopefully this report will open some eyes and lead to positive changes. 

New rules are going to lead to more injuries?

I blogged last week about the new rules in the NFL and NCAA that are targeted at preventing football players from hitting their opponent in the head or leading with their head when making a tackle.  The purpose of these rules is to cut down on the number of head and neck injuries.  I've heard some commentary recently on ESPN from former players saying that these rules will cause an increase in the number of knee injuries.  They think because defenders cannot tackle offensive players by hitting them in the head, they will now target their knees, because they don't have any other option.  Now, I didn't play football, or coach football, but it seems to me like there are a lot of other options besides hitting a player in the knees or the head.  I know when I was working as an athletic trainer with the football teams at Southern Miss and Auburn the players were not taught to tackle by hitting in the head or knees.  They were taught to hit a player in the chest or middle of the body and then wrap them up.  I think there are other options for tackling besides the head and the knees.  It may take some adjustments, but I don't think these new rules should cause a huge spike in the number of knee injuries.

Tackling

If you are a football fan, then you know that the start of football season is less than two weeks away.  One of the hot button issues this off season has been tackling, specifically as it relates to hitting another player in the head or a tackler using his head to hit another player with.  The National Athletic Trainers Association (NATA) released a position statement last week urging officials to consistently penalize players that lead with the crown of their head.  The full statement can be seen here.  I've heard a lot of coaches, analysts, and former players complaining about the new rules and the fact that the NCAA and NFL officials will call more penalties on these types of hits.  While it will change the way some players tackle, the benefits of these new rules far outweigh the risk of a player potentially missing a tackle because he cannot lead with his head.  I will outline the theory behind these new rules below.

As you can see in the picture above, the tackler on the right of the screen is making contact with the offensive player with his head down, or in a flexed position.  This results in axial loading of the cervical spine.  When the head is in a natural, upright position, there a slight forward curvature of the cervical spine.  When the neck is flexed and the head is down, this removes the natural curve from the cervical spine, and easily allows

the force to be transmitted from the head down the cervical vertebrae.  In the picture directly above, you can see how the spine is loaded, and as the amount of force increases, the amount of deformation to the cervical spine also increases.  This can ultimately result in a fracture and/or dislocation of the cervical vertebrae that causes paralysis.  The only tackling technique that results in axial loading to the cervical spine is one in which the head is down and contact is made to the crown of the head.  While it is still possible to sustain a neck injury when tackling with the head up, the chances of sustaining a life threatening/altering injury are greatly decreased.  This article contains more information on tackling techniques and the dangers/risks associated with head down tackling.  While I am sure this issue will remain a controversial topic, the best way to prevent catastrophic head/neck injuries is to prevent players from tackling with the head down.

Tim Hudson's Injury

If you are a baseball fan, then you have probably heard and seen about the injury to Braves' pitcher Tim Hudson last week.  While covering 1st base, Eric Young Jr. inadvertently stepped on Hudson's right leg just above the ankle on the lateral side.  Early reports where that Hudson fractured his ankle.  This is a very vague description, as there are several bones in the ankle.  After undergoing surgery, it was revealed the Hudson fractured his fibula and tore his deltoid ligament.

The fibula is the bone located on the lateral side of the lower leg.  It runs from just below the knee down to the ankle, and forms the lateral portion of the ankle.  The very distal (bottom) end of the fibula is called the lateral malleolus.  Looking at the picture of the injury, Hudson fractured his fibula just above the lateral malleolus.  Since the fibula is thinner than the tibia and doesn't play as large a role in weight bearing, the recovery can be easier (still difficult) than a fractured tiba (the medial shin bone that bears about 90% of our weight when standing).  Hudson also tore his deltoid ligament, which is the thick ligament on the medial side of the ankle.  It is actually a collection of four ligaments shaped like a triangle (deltoid).  It helps prevent the ankle from excessive eversion (when the bottom of the foot moves away from the midline, such as in the picture above).

Although Hudson is 38 years old, he has a pretty good chance of pitching again.  His rehab from the injury will probably take 3-6 months, and he should be ready to go by spring training.  Hopefully he can make a full recovery.

Platelet-Rich Plasma Injections

During the last blog post, I mentioned that one of the treatments Bryce Harper received for his injured knee was platelet-rich plasma injections.  This has become a popular treatment among athletes these days.  It is typically used during the inflammatory phase of the healing process to help accelerate recovery.  It involves taking a sample of blood from the same patient, separating out the platelet rich plasma, and then injecting the plasma into the injured tissue, such as a tendon or a ligament.  The patient must avoid exercise for a few days before starting or re-starting the rehabilitation program.  There are animal studies that have shown it is effective, and many athletes have claimed it has helped them improve.  It will likely become an even more popular treatment choice in the future.

What's wrong with Bryce Harper's Knee?

I apologize for the delay between blog posts.  Things were very hectic at the end of the spring semester and the beginning of the summer.  If you are a baseball fan, then you know Bryce Harper, the young star outfielder for the Washington Nationals, injured his knee over a month ago when he collided with the outfield wall.  Haper missed a few games, played in a few, and then recently went on the disabled list.  So, what injury did Harper sustain?

Harper was diagnosed with bursitiis, which was confirmed today by Dr. Andrews.  Bursitis is inflammation of a bursa.  A bursa is a fluid filled sac that is found near many of our joints, such as the knee, ankle, elbow, and shoulder.  In the picture above, you can see that there are four bursa around the knee.  It is likely that Harper injured his prepatellar bursa when he ran into the wall.  The prepatellar bursa is located directly above the patella.  It is very superficial and easily injured during collisions.  When a bursa sac is irritated, it can cause a lot of swelling and inflammation around a joint.  This can make movements of the knee painful and difficult.  It generally does not cause swelling within the joint, because the bursa is located outside the joint.  The best course of treatment for bursitis is rest and anti-inflammatory medication.  However, this option is not often chosen during the middle of a competitive season.  Because Harper's knee was not responding, they had to place him on the disabled list.  I will discuss the treatment he received for this injury from Dr. Andrews in the next blog post.

Rash of Injuries

There have been a lot of injuries lately in professional sports, from Zack Grienke to Jose Reyes to Kobe Bryant.  On Wednesday night, Grienke, a right handed pitcher for the Dodgers, fractured his left clavicle after fighting with Carlos Quentin.  It's difficult to tell if the injury occurred during the initial collision or when Grienke hit the ground.  The clavicle serves as the link between the axial skeleton and the appendicular skeleton.  Anytime you move your shoulder, the clavicle rotates as well.  Although Grienke broke his left clavicle, and he is right handed, the left arm is still important for a right handed pitcher.  Grienke had surgery to place a rod in the clavicle and help stabilize it.  The Dodgers estimate he will be out for around 8 weeks.  Once the injury heals, he will have to build his arm strength back up and undergo a rehabilitation assignment in the minor leagues before he can pitch in a major league game.  This will likely take about 2-3 months.

Cameron is Two

This post is not really kinesiology related, but Cameron turned two last Friday, and I thought I would add some pictures of him to the blog.  He has grown up so much the past two years and is really smart.  I said I wouldn't try to force him to learn his anatomy, but he really enjoys learning information and I just couldn't resist.  He can point to and say his brain, ears, eyes, nose, mouth, pecs, heart, belly, elbow, shoulder, patellas (it comes out more "tella", but that's impressive for a two year old), and ankle.  He can also stretch, show his muscles, and he likes to try and do pushups.  Who knows, he might just follow in my footsteps and pursue a career in kinesiology!  Below are some pictures of him.

 Maybe a future professor?

 He's finally started wearing baseball caps, so of course it has to be a Cardinals hat!

 Pointing to his pecs.

 Showing his belly.

 Stretching.

He's gained almost 25 pounds and grown around 15 inches in 2 years.

There is hope

If you have read this blog in the past, then you know I hate the term "muscle memory."  Just a short recap, but the reason for this is that the muscle cannot remember anything.  All movement is a coordinated process between the nervous system and the muscular system.  However, athletes, coaches, and even so called experts on ESPN (I'm talking about you Sport Science Guy) continue to use the term.  It was refreshing to read an article this week about Cleveland Indians pitcher Trevor Bauer and his attempt to change his pitching mechanics, and to hear him use the words "neuromuscular programming" instead of "muscle memory."  He essentially said that by attempting to change his pitching mechanics, he is trying to overwrite 10 years of neuromuscular programming.  I don't know a lot about Bauer but he seems like a very smart guy.  He is essentially attempting to make some changes to his throwing motion, and this will require the brain to activate different motor units at different frequencies and with different timing patterns.  Neuromuscular programming is a good description of what is going on.  It is certainly better than muscle memory.  Hopefully more athletes and coaches will start to use this terminology and it will start to replace incorrect terminology.

Classic Lateral Ankle Sprain

Last Wednesday night, Kobe Bryant suffered a lateral ankle sprain.  You can see the video here.  Bryant went up for a shot and his left foot landed on the foot of the defender, forcing his ankle into inversion (bottom of the foot turning towards the mid-line) and plantar flexion (foot pointing down).  This type of mechanism of a lateral ankle sprain occurs commonly in sports like basketball and volleyball.  The players are in close proximity to each other which increases the likelihood of them landing from a jump onto the foot of another player.  The reports said Bryant suffered a severe ankle sprain, but since he was able to attempt to play on Friday, it was likely a Grade II (moderate) ankle sprain. 

You can see in the picture above that the mechanism of a lateral ankle sprain damages the lateral ankle ligaments, which include the anterior talofibular, the posterior talofibular, and the calcaneofibular ligament.  Bryant likely suffered damage to all 3 ligaments.  The best treatment of this injury is a period of rest, management of pain and swelling, followed by rehabilitation to restore range of motion, strength, proprioception, and functional movements.  Since the Lakers are trying to get into the NBA playoffs, rest is not really an option for Bryant (although he isn't playing tonight because of this injury and because he has the flu).  This injury will definitely affect him the rest of the season, although he is a great athlete and has shown the ability to play through pain in the past.

Trip to Greenville, SC for SEACSM conference

Early on the morning of February 14, I departed Starkville with 3 undergraduate students for the 2013 Southeast Chapter of the American College of Sports Medicine annual conference in Greenville, SC.  The three students were Alisan Abernathy, Murry Adams, and Anna Comer.  We had been working together on a research project since this past summer investigating the relationship between ankle joint laxity, balance, and landing kinetics.  Each of the students made their own presentation based off of the data we had collected so far.  They all did a wonderful job with their presentation and we received several compliments.  They also competed in the student quiz bowl and did very well.  Below are some picture from the trip.  We have a little more data to collect before we start working on a paper to submit for publication.

 Murray in action.

 Murry and his poster (the girls didn't want individual pictures with their posters.

 The students and me.

 Getting ready for the quiz bowl.

Taking in a little minor league hockey on Friday night.  We had great seats.

Career Ender

I have blogged previously about Chris Carpenter and the surgery he had last summer for thoracic outlet syndrome.  The surgeon has to remove Carpenter's first rib on his right side to take the pressure of the nerves than run from the neck down into the shoulder and the arm.  Carpenter had been experiencing weakness, numbness, and a loss of sensation in his right arm for a long period of time.  He was able to come back in a little over 3 months and pitch in 6 games at the end of the regular season and playoffs.  He pitched about like what you would expect someone to pitch only 3 months removed from major shoulder surgery.

Earlier this week it was announced that Carpenter was having a re-occurrence of the thoracic outlet symptoms that lead to the surgery, and that he would not be able to pitch in 2013, and likely not ever again.  Although this was not a complete surprise, given his injury history, it is still a disappointment.  Carpenter is one of the best pitchers in Cardinals' history and one of the greatest postseason pitchers ever.  However, he has had multiple shoulder and elbow surgeries over the course of his career, and these injuries and surgeries begin to take a toll on the body.  Hopefully once he stops pitching the symptoms will subside and he can have a normal life, although he will likely contain to experience some of the symptoms in his throwing arm.

Life Threatening Injury

I was reading the latest edition of the NATA (national athletic trainiers association) news and came across the story of Houston football player D.J. Hayden, and how the quick response of his athletic trainer, Mike O'Shea, likely saved his life.  If you are a member of the NATA, I encourage you to read the story.  If you are not a member, this ESPN.com article offers a pretty good summary of the injury. 

The injury that Hayden suffered was a torn inferior vena cava.  The inferior vena cava is the large vein that carries deoxygenated blood from the lower extremity into the right atrium of the heart.  A tear of this structure results in massive internal bleeding and is a serious medical injury.  According to the story in NATA news, Hayden went up to intercept a pass and another teammate's knee hit him just underneath the sternum, right below where the protection from his shoulder pads ended.  O'Shea examined Hayden on the field and again on the sidelines, and quickly decided to move him into the locker room.  Because Hayden's signs and symptoms were not adding up with a typical chest injury, O'Shea and the team physician went ahead and called the paramedics, who decided to take him to the nearest trauma center.  The doctors at the hospital suspected a ruptured spleen or liver, but soon discovered that it was his inferior vena cava that was ruptured.  According to the article, there have not been any documented cases of a torn vena cava occurring during athletic competition.  It more commonly results from a gunshot wound or car accident.

The doctors were able to repair the rupture in his vena cava, and Hayden is expected to make a full recovery.  The doctors stated that the fact Hayden also broke his diaphragm during the injury likely helped save his life, because it allowed the blood from the ruptured vena cava to pool in his adbomen instead of around his heart.  The doctors also stated that if he had arrived at the hospital 5 minutes later he likely would have died.  This was a remarkable job by the entire medical staff, beginning with the athletic trainer.  The typical survival rate for a torn vena cava is around 5%.  You never know what may happen when you step out onto the field or court to cover a practice or game, and the actions of this athletic trainer helped save a life. 

Robert Griffin III latest knee injury

I hope that everyone had a great holiday season and a happy new year.  As we wrap up the first week of classes at Mississippi State, I thought I would talk some about the latest Robert Griffin III knee injury.  A few weeks ago, Griffin sustained a sprain of his right LCL.  He missed one week of action, but then came back and played in the final two regular season games.  This past Sunday, Griffin sustained a tear of his right ACL, likely on the play in the picture above.  There has been much debate about rather or not he should have been playing, and if the coaching and/or medical staff is to blame for this injury.

There are a number of factors that can cause an injury, and it is impossible to isolate just one factor and say it is the primary cause.  One would have to believe that the Redskins medical staff, led by Dr. Andrews, would not allow Griffin to play if they believed he was at serious risk of injury.  Due to his recent LCL injury, his knee was probably not quite as stable as it originally was, but there is no way to know if that caused the injury.  He could have sustained the ACL tear even if he was playing on a completely healthy knee with no history of injury.  A number of factors likely lead to this injury, including his previous LCL sprain, his previous ACL reconstruction of the same knee, fatigue (end of game and season), the condition of the field, and the awkward position he is in trying to field the snap.  One could argue that if the snap had been better, this injury would have never occurred.  The point is that it is impossible to pinpoint the exact cause of the injury.

The other thing I have heard several times is that Griffin can be back by the start of the 2013 NFL season because Adrian Peterson did so this year.  I'm not saying that he can't, but it is impossible to make direct comparisons.  While both players are world class athletes, this is Griffin's 2nd reconstruction of this right ACL.  Everyone also heals and rehabilitates at different rates.  It typically takes anywhere from about 8-12 months to come back after ACL reconstruction.  He has a good chance to play next year, but nobody knows for sure at this point what level he will be at.