The most important findings of this study were that upper limb injuries represented 6.8% of total injuries and the shoulder represented the most injured location. In addition to it, glenohumeral and acromioclavicular dislocation were the most common type of lesion and responsible for all the recurrent lesions. Injuries in soccer have a significant impact on the health and performance of players and affect the involved clubs and athletes financially [3,4,5]. For instance, our results, showed players submitted to surgical treatment presented longer time to return to play.
In general, the incidence of injuries in both championships was 19.6 per 1000 hours played. For upper limb injuries, this incidence was 1.33 per 1000 hours played. A previous study in the English women’s and men’s soccer Leagues revealed an incidence of 31.1 general injuries per 1000 hours of play [10]. Jan Ekstrand et al. reported an incidence of only 0.23 per 1000 hours played for upper limb injuries when monitoring the European soccer league [9]. The differences in results may be attributed to the match particularities in each league, duration of the season, sample size, and the quality of data regarding injuries during the tournaments [9, 11].
The results showed an upper limb injury incidence of 6.8% in relation to total injuries. Shoulder injuries accounted for 4.3% of the total injuries and 63.3% of upper limb injuries, corroborating similar findings in previous studies [4, 12]. Although upper limb injuries are less frequent in soccer players, the sport has evolved into a high-speed game with tactical plays involving more significant physical contact, which may predispose to traumatic injuries [8, 13,14,15,16].
The increasing prevalence of shoulder injuries has become a health problem for athletes, which led to the development of the FIFA 11+ program to prevent them [8, 16]. The program was developed with a focus on goalkeepers, as previous studies has shown that players in this position have a higher incidence of shoulder injuries [9, 17,18,19]. Our study showed few injuries in goalkeepers, but this may be due to sample bias. In addition, although shoulder injuries are the most frequent upper limb injuries in soccer, other injuries occur and negatively impact players and clubs [17, 19, 20]. Thus, additional studies are needed, focusing on upper limb injuries in soccer athletes, to better understand the changes in the sport and the profile of the injuries [19].
Forward and players in defending positions (defender, defensive midfielder and side-backs) had higher rates of upper limb injuries and presented with a higher injury risk. These results corroborate previous studies in which changes in the direction of play, speed, and strength cause attacking and defending players to collide with opponents, favouring the occurrence of injuries [13,14,15]. However, other studies in the literature report that the goalkeeper has the greatest potential to suffer an upper limb injury [9, 18, 19]. Differences in the results may be due to sample size differences between studies, game style and the tournament characteristics.
In this study, 66.9% of upper limb injuries resulted in a TRP greater than four days, with an average of 19.1. Considering that each season had an average duration of 154.9 days, players who suffered injuries lost approximately 12% of the season. In cases that required surgery, the lost time lasted the remainder of the season. A previous study similarly reported that the average TRP of players due to injuries was 12% off the season; however, the primary injuries affected the lower limbs [21].
The mean TRP was 23 days per 1000 hours played. Thus, the results of this study showed a longer mean TRP for upper limb injuries than lower limb injuries, according to the literature [9, 17, 18]. We believe this is due to soccer being a primarily lower limb sport, making injuries more common to this part of the body, even though most of them are mild. On the other side, upper limb injuries are less common, but often caused by more intense traumas, leading to longer TRP. Therefore, measures to prevent upper limb injuries need to be developed, and it is recommended that athletes strengthen this part of their body.
Previous studies in Brazilian Championships reported a rate of 11.9% for surgical interventions compared to 9.4% in this study [22]. Nevertheless, the TRP of the players who needed surgical intervention exceeded that of those who did not need it, leading to more significant implications for clubs and athletes.
The TRP players experience due to an injury can impact the performance of their clubs as well as the athlete’s performance. The severity of the injury and the need for surgery were both associated with prolonged lost time [3, 23]. In addition, the lost time of a player due to an upper limb injury increases club financial expenses [18]. These results bring awareness of how beneficial prevention of upper limb injuries are to mitigate lost time consequences.
Several studies report on the mechanisms of injuries in soccer and how to prevent them, but most focus on lower limb injuries [7, 24]. In general, injury prevention in soccer reduces the incidence of injuries and health costs [5, 25]. However, more research is needed to understand the mechanisms of upper limb injuries in soccer and better assist coaches, doctors, and athletes in preventing these injuries [26].
This study’s primary limitation is the possible data collection bias, as it is inherent in epidemiological studies, since the club physicians were responsible for entering data into the platform. Nevertheless, it is a four-year-long prospective study, during this period, there were some changes of physicians at the clubs. To reduce bias of data collection, every physician was trained how to fill the survey and every time the club physician was substituted, we were informed, and the new physician was trained too. Nevertheless, it was possible to collect novel data of two major Brazilian soccer championships regarding upper limb injuries. Another limitation is that there is no consensus of the definition of injury in the literature, making it difficult to compare our results with other studies. In addition, data was not collected for injuries that occurred during the training sections.
