The Effect of Playing Position on Injury Risk in Male Soccer Players: Systematic Review of the Literature and Risk Considerations for Each Playing Position
TAKE-HOME POINTS
- Playing positions haven’t been extensively evaluated as an injury risk factor in elite, non-elite, and youth soccer (football).
- Different playing positions may have different injury rates and patterns due to different load, different movement patterns, and peculiar combination of anticipated and non-anticipated (reactive movements).
- The existing literature suggests that goalkeepers seem to be at lower general injury risk if compared to outfield players in male soccer (football).
- There is also a tendency towards strikers (forwards) to be at higher risk of match (but not training) injuries. This result is however not consistent between all the studies considered and should be interpreted cautiously.
- When studying injury risk in male soccer match and training injuries should be considered separately and playing position should be evaluated as a potential predictor of injury incidence.
We will now review the findings of our systematic review based on player position. One of the more consistent trends that we found is the possible occurrence of different injury epidemiology in GKs compared to outfield players. One study reported a significant lower incidence of match injuries for GKs, 12.9 injuries per 1000 game hours vs 22.6 injuries per 1000 game hours of outfield positions.16 This result is remarkable, even considering the very long observational period (15 seasons). Other 2 studies, not reporting position specific injury incidence (but proportion of injuries) also agreed on the topic.12,13 On the other hand, Morgan and Oberlander9 reported no differences between GKs and other positions. Anecdotally, unpublished Major League Soccer data regarding the most recent seasons seems to support these findings with GKs sustaining the lower proportion of injuries. By a physiological point of view, somatotype and body composition have been reported to differ between GKs and the other playing positions in young male soccer players.21 The uniqueness of the GK somatotype and role may reflect on a predisposition to a different pattern of injuries. Ekstrand and colleagues22 reported that GKs have a higher incidence of upper extremity fractures, the same group demonstrated a possible tendency for more head and neck injuries9 and a lower risk of medial collateral ligament injuries.23 On the other hand, GKs seems to be at lower injury risk for the playing pattern differences with outfield players. The reduced distance GKs cover during the match, as well as less direct contacts with opponents, may be factors that potentially explain this finding.
In relation to forwards, 4 studies interestingly stated that forwards were at increased risk of injury,12-14 although 1 report had similar risk of injury with forwards and defenders.8 Most of the studies only on match injuries reported some association between forward position and injury risk (Figures 2A, 2B), so attackers may be at higher risk of match injuries when compared to the other playing positions. There are different possible explanations for this finding. First, it is demonstrated that the clear majority of soccer incidents happen in the mid-defensive zone and in the score-box,24 2 typical attackers’ zones, where most of duels and tackles may happen. So, forwards may be more prone to match injuries because of the intensity of match play in their typical playing zones. Also, fast kicking and acceleration/deceleration activities of the attackers may predispose for thigh muscle injuries, accounting up to 25% of the total lay off time in professional soccer.25 However, these considerations are still yet to be proven.
When considering defenders, 1 report indicated defenders (and forwards) to be at potential greater risk of injury,8which is similar to the report from Shalaj and colleagues,17 although it did not report a statistically significant result. A direct playing style, with defenders and strikers being more involved in the game can potentially explain this finding. However, the specific epidemiology of defenders may be more complicated. Defenders may be predisposed to knee injuries, such as injury to the anterior cruciate ligament (ACL). In fact, Walden and colleagues,11 in a video-analysis study, reported that the 77% of ACL injuries happened in defending situations. In addition, Brophy and colleagues,6 in another video-analysis study, reported a 73% of ACL injuries happened while defending. A likely explanation is the nature of the defender’s role in soccer, reactive to the attacking team actions. Many times, defenders try high risk maneuvers while tackling the opponent, with minimal motor planning time and consciousness. This is well described by Walden and colleagues,11 with the pressing mechanism ACL injury, when the injured player is pressing the opponent in the attempt to get the ball but eventually falls into a high-risk position.
When considering MFs, Deehan and colleagues15 found a significant higher risk in MFs in youth soccer. This result is partially according to Morgan and Oberlander18 who reported a non-statistically significant greater injury incidence in MFs. MFs are generally the players that cover more distance during a soccer match and it is logical to think that they would be predisposed to a large volume of acceleration/deceleration activities,19 potentially relating to injury risk, especially to muscles injuries. A previous study on thigh muscle injuries in youth soccer reporting higher injury risk in MFs, followed by forwards.19 Consistent with these results, another study on a mixed male and female cohort on high school soccer revealed more injuries in MFs, followed by forwards.26
Continue to: The results of this systematic review...
