Low Back Pain in Football

Low back pain (LBP) is one of the most common ailments in US Health Care.  Current literature indicates that 8 out of 10 Americans experience one form or another of LBP.  Of those, 60% have a reoccurrence of that LBP within 2 years of the initial episode.  Currently it is the 2^nd most common reason that people seek medical care with their primary care physician and is the #1 work related disability in those under the age of 40.  With the prevalence of LBP amongst the general population, it makes sense that it is also an injury that is prevalent in athletics.  According to the current research, LBP is one of the top 10 orthopedic injuries that occur in athletics.  Although it varies across the sports, it still ranks high amongst all the sports. 

In American Football, LBP is a common orthopedic condition that is dealt with on the sidelines, in the athletic training room and in the sports medicine clinic.  It can also be a difficult injury to treat in a collision sports such as American Football.  As such, if we can in determine which factors place players at risk, then we can have a better idea of how to prevent and potentially treat when the injury does occur.  In the September issue of the American Journal of Sports Medicine, the authors of the study entitled “Risk Factors for Lumbar Disc Degeneration in High School American Football Players” attempt to do just that. 

Methods:  In this study, the authors looked at 192 high school athletes playing American Football to determine risk factors for disc degeneration and LBP.  Radiographs and MRIs were obtained on each of the high school football players when the players enrolled in the sport and then again at 2 years later at the end of their 2^nd academic season.  Of these players, 160 played 2 consecutive seasons and 32 stopped before completing their 2^nd season. 

Results:  What the authors found was that the signal density for the nucleus pulposus decreased more in those players who competed in 2 consecutive seasons of play.  There was also a correlation with decreased signal intensity by position with the lineman having much greater decrease than other positions. Visual analog pain scales were also much higher for LBP in those who competed in 2 consecutive seasons when compared to those who did not. 

Discussion:  Based on the results of this study, the authors conclude that consecutive seasons of play in American Football does increase your risk for LBP and disc degeneration.  This being said, there are some things that must be considered before making this conclusion. 

1. Does this have application in the US?  This particular study was done in Japan.  Being that all the football players were Japanese, can influence the data and conclusions in several ways. 
1. Physical makeup of the players.  Do Japanese football players have the same physical and physiological characteristics as American football players?  With cultural differences, is one at more risk than the other?  How does cultural diet fit into that and the impact this can have on hydration of the disc?
2. Philosophical approach to the coaching of the sport.  Is there a difference in philosophical approach to American Football played in Japan versus American Football played in the US?  Is there coaching differences that may or may not lead to increased rates of injury?  Knowing that certain coaching styles and approaches can lead to more injuries, is there a philosophical difference that needs to be considered when looking at the data?
3. Philosophical approach to the training for the sport.  Is there a philosophical difference
   in the strength training methodology that is applied to the sport in the US versus Japan.  For example, a lot of schools are starting to implement more core and hip training as well as dynamic stretches which we know has an impact on low back injuries.  This training aids in distribution of the force in the spine in a way that it was anatomically designed to withstand.  We also know that improvements in core proprioception aids in not only decreasing risk for LBP but also adds in improving athletic performance.  Is this same methodology that is applied in Japanese version of American Football?
2. What other factors may be leading to some of the results?
1. Strength training methodology.  Although mentioned above as a way of reducing injury rates, if applied incorrectly, then it can lead to increased injury rates.  For example, with squats and some of the Olympic lifts that a lot of the high school teams use, if these are performed incorrectly with poor technique, then this can lead to increased stress to the facet joints and disc in the lower lumbar spine.  We also know in the US that the training for lineman is different than other players.  Are some of these differences adding to increased risk for injury in these players.
2. Hydration.  We know the H2O content of the disc is high and that chronic dehydration can lead to drying out of the hair, skin as well as tissues inside the body (like this disc).  The recommended daily dose of caffeine is 420 mg/day and the average American gets between 800 to 1600 mg/day.  Although there are not any current studies out there looking at high school students, we can speculate that the consumption of the average high school student is closer to the higher end than the lower end.  With increase in caffeine consumption comes dehydration.  With lineman tending to have a larger BMI than other players, do these dietary differences also lead to increased dehydration and increased risk for LBP with this position? 

 Although this study is a great start to identify those at risk and specifically positions at higher risk, does this really give us any meaningful information which we can use to reduce that risk?  If we take this information in conjunction with the considerations above, then we should be able to implement some intervention strategies that would aid in reducing this risk.

Reference:

Nagashima M, Abe H, Amaya K, Matsumoto H, Yanaihara H, Nishiwaki Y, Yoshiaki T, Matsumoto M.  Risk Factors for Lumbar Disc Degeneration in High School American Football Players.  Am J Sports Med.  41:2059-2064.  2013.

Zazulack B, Hewett T, Reeves P, Goldberg B, Cholewicki J.  Deficits in Neuromuscular Control of the Trunk Predict Knee Injury Risk: A Prospective Biomechanical-Epidemiologic Study.  Am J Sports Med; 35:1123-1130.

DeRosa & Porterfield. Mechanical Low Back Pain: Perspectives in Functional Anatomy. Saunders. 1998

Hides J, Richardson C, Gwendolen A. Multifidus Muscle Recovery Is Not Automatic After Resolution of Acute, First-Episode Low Back Pain. Spine. 21:2763-2769.  1996