Can a Specific Neck Strengthening Program Decrease Cervical Spine Injuries in a Men’s Professional Rugby Union Team? A Retrospective Analysis Robert Naish, Angus Burnett, Sally Burrows, Warren Andrews, and Brendyn Appleby
A review by James Shmagranoff
As the Exercise Specialist and Manager at Purdue University Northwest, I spend a great deal of time training athletes and helping them to avoid injury with strength exercises. Working with a large number of athletes in contact sports I thought this article would be great to review due to the ever increasing number of concussions and spinal cord related injuries in contact sports .
Introduction
An item of concern among Rugby Union players due to the impact and exhaustion of the sport is cervical spine injuries. Cervical spine injuries such as neck muscle or cervical facet joint strains, joint dislocations in those aforementioned areas, or nerve root neuropathy are common among forward players. During play resumption, or scrum, forces of impact to player’s cervical spines coerce the neck into a hyper-extended or hyper-flexed position. The vulnerability of players during a maul (when the ball carrier, a team mate, and an opposing player are on their feet) and a ruck (when two components battle for the ball on the ground) can cause the neck to go into flexion. This is not to mention that forceful tackles can have damaging effects to the cervical spine all dependent on the collisions as well. Because of the risk of severity that cervical spine injuries pose, rule changes and tackling guidelines have been deliberated to avoid such injuries.
However, strengthening the neck musculature has also been considered, as it appears that this may help slow the abrupt force put upon the cervical spine to forwards, who are at the most risk for such injuries. Utilizing a two year period, data from the previous season on injuries and amount of days associated with missed competition and training resulted in the addition of neck strengthening exercises for the following year. This data would be used to determine if a 26-week training cycle would help to decrease the amount and severity of neck injuries and if there would be a significant increase in isometric neck strength.
Methods
From 2007-2008 and 2008-2009, a retrospective analysis was conducted on a professional Rugby Union team of 27 players common to both seasons consisting of 15 forwards and 12 backs. At the beginning of 2008, a progressive and supervised isometric neck strengthening intervention program was added to the strength and conditioning program. This training consisted as a 26-week cycle broken into two 13-week parts—a strengthening phase and a maintenance phase. Isometric exercises were chosen as a means to eliminate the risk of movement to the cervical disc, facet and neural structures, as well as to mimic the motions that necks can be forced into during competition. The only direction that was excluded was axial rotation, as there was no equipment able to produce the rotation isometrically. There was no addition of neck stretching, and a baseline strength test was taken on each athlete prior to beginning the new programming. Weeks 1-5 were used for upright positions, and the following weeks provided more advanced exercises such as: angle and pull modification, cable holds in bent positions, neck extensions, and left and right lateral flexion. The exercises used specifically for this programming were: Isometric cable hold-neck flexion, - neck extension,-right and left lateral flexion, -45 degree neck flexion left and right, -bent over neck extension, -bent over lateral flexion; tight head prop isometric cable hold bent over right lateral neck flexion with shoulder/pectoral fly; loose head prop isometric cable hold bent over later neck flexion with shoulder latissimus dorsi pull-down; scrum truck simulation lateral neck flexors and extensors. For individuals lacking in strength levels, additional sets were prescribed to accommodate for the weaknesses. Front row players utilized a simulation exercise where external resistance was applied to the head at varying angles and players were told to maximally contract against the resistance for five seconds. Five seconds was chosen based on previous studies mentioning that that amount of time was successful in improving neck pain.
Data collection and analysis primary outcome variables: Cervical spine injuries and severity of injury, as determined by two senior physiotherapists and MRI, was measured by the number of days players had to be absent from training and competition and was input into a database based on four codes and if the injury was training, match, or recurrent related. If an injury did not cause a loss in training or competition, it was left out of this study.
Secondary outcome variable Isometric neck strength: A baseline isometric neck strength test was conducted at the start of 2008-2009 season and again at the 5 week mark of the program. Because of their athletic capabilities, it was thought that after 5 weeks, they may see acute neck strength increases. Neck strength was measured in flexion, extension, and left and right lateral flexion. To do so, a harness was worn by each participant and attached by a stiff wire cable to a load cell, the participant sat on a vertically positioned incline bench, their heads were positioned so the cable was parallel to the floor, a resting pad was placed on the chair to eliminate movement of the body, and the feet were placed on balance discs to minimize feet force increases in neck strength testing. Testing order was a block randomization, and each participant would be given 30 second rest between exercise. Three submaximal isometric contractions were held for 5 seconds prior to testing the four directions.
Match and training time: Training time was measured in minutes and sessions per week as a whole team, and match time was calculated as the time it took to complete a match. Individual match and training times were not able to be calculated.
Statistical analysis: Significant differences were measured using the non-parametric Wilcoxon signed rank tests for paired data. To determine if the amount of injured players was altered over time, McNemars test was used.
Results
No significant difference was found between 2007-2008 and 2008-2009 in the numbers of players with cervical spine injuries, the total number of cervical spine injuries, the number of training injuries, the time loss from matches or training related to injuries, or the initial 5 week strength program. There was, however, a significant decrease in match related cervical spine injuries.
Discussion
The most important conclusion of this study is that there was a significant decrease in the amount of game related cervical spine injuries. While no significant decrease was seen in training related cervical spine injuries, this could be due to the fact that training is often more controlled than matches. Also, the nonsignificant finding of 5 week acute neck strength gains can be attributed in part that these are professional, well-conditioned athletes. Unfortunately, due to the demand of a professional Rugby Union player, there was no time to retest neck strength upon the completion of the 13 week maintenance phase. It was deemed that there would probably not be any significant increase anyway. Now, since it appears that a significant decrease in injury is paired with a non-significant finding of improved neck strength, there are other variables that can attest to these findings. Adaptations in proprioception, muscle co-activation, and stabilization of flexors may have improved. There is also the possibility that this was just pure coincidence that this season led to fewer injuries. Limitations of this study included lack of randomized controlled trials, small number of returning players, competition level as a professional, and that the neck strengthening program only utilized isometric movements.
Conclusion
The reduction in match based cervical spine injury based off of this neck strengthening program should be further examined to determine if this was due to pure coincidence or the implementation of such programming.
Application
While this study seemed to have limitations in participants as well as demographics, any data that points towards the decrease in head and neck injury shows great promise. Head and neck injuries are a huge concern among anyone who deals with athletes. Rugby athletes know that there is a risk associated with a hard contact sport, as all athletes who participate in them do, but they would also probably jump at a program that could even slightly reduce their risk for injury. Even the hope that a debilitating rugby injury risk such as paralyzation could be reduced, would show hope for these athletes. Even though I have not worked with rugby players to date, I have worked with a number of clients in other high impact sports such as football and MMA fighters. Research demonstrating a reduction in cervical spine injuries are of great asset to me and help me in periodizing and programming specific neck strengthening protocols for all of my athletes and clients.
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