The following study officially debunks the long-standing myth that Futsal causes way more injuries to a player than outdoor does. Its a very thorough study with a lot of detail. We’ve highlighted in bold blue some of the more inportant areas to make your reading of it a bit easier.
Thanks to Rob Varela from Dural (NSW) for getting hold of it.
Analysis of the incidence and factors related to ankle sprains in adolescent athletes of soccer and futsal. A comparative study
FIFA (Fédération International de Football Association) it is an entity with 204 affiliated nations that manages Soccer, the most popular sport of the world with approximately 200 thousand professional athletes and 240 million amateurs1, and Futsal, distinguished as the collective sport in biggest world ascension, being the most practiced sporting modality in Brazil with more than 12 million followers2.
The most common injuries in soccer are muscular overstretching (35-37%), sprains (20-21%) and bruises (16-24%), being the thigh (23-24%), the ankle (18-19%) and the knee (15-17%) the places of larger incidence3. For being a relatively recent sport, futsal presents few studies on its incidence of injuries. Observing the World Futsal Championship in Guatemala in 2000, Junge et al.4 found 191 injuries for every 1000 hours of game practice. According to Lindelfeld et al.5, ankle and knee injuries stand out, especially ligament-type injuries.
The sprain is the injury of largest occurrence (approximately 75%) in the articulation of the ankle6, being considered the most common injury in sports. It is by far responsible for the athletes’ removal from competitions in a season7. Besides the total or partial rupture of the ligaments, this injury is characterized by the stretching and/or rupture of muscular tissues, the impairment of peripheral nervous structures and capsular loosening8.
The articulation overload during the inversion of the ankle is responsible for 85% to 90% of ankle sprains6. That position, especially due to the associated foot flexing, reduces the contact surface between the talus and the tibia, causing larger joint instability7. Besides, the thick deltoid ligament and the position of the lateral malleolus protect the articulation during a sprain in eversion9.
An ankle sprain may cause a mechanical-functional disorganization not only in an ankle-foot level, but it could also reach knee and spine10. According to Saunders11, this injury is also responsible for chronic pain or instability in 20-50% of the cases, and, in the long run, that articulation instability may cause degenerative processes in the ankle12.
Thaker et al.13 mentions nine studies to claim that the record of ankle sprain is an important risk factor for the athlete to have a new injury. It is believed that the high number of recurrences in ankle sprains is related to the reduction of a function denominated proprioception in ankles that already had this injury14,15.
The proprioception is a mechanism of measuring sensorial feedback that includes the feeling of the articulation’s movement and the feeling of the position of the articulation, being fundamental in its functional stability. Proprioceptive deficits cause a decrease of the neuromuscular control, leading to functional instability and, possibly, to repetitive articulation injuries16.
Proprioception seems to have alterations during the adolescence period, more specifically during the outbreak of pubescent growth. Data obtained by the Test of Brace indicate that the boys demonstrate increase of motor coordination with the increment of the skeletal age, except for a slight decline in the maturity graduation 32 and 33 (between 12.5 and 14 years of age). The evidences indicate that quick changes in the physique, strength and bodily proportions need to be adapted in a sensorial-motor operation level, and it is possible that the dwindling rate of balance and motor gain noticed by several investigators in the puberty may be associated to such adjustments17.
It is also known that the phase of growth outbreak consists of a period where the youths are more prone to injuries18. Studies with soccer adolescent athletes confirm that the largest number of occurrences is at the age of 14, being the knee and the ankle the most affected areas19.
This way, by adding the natural risk of sprain with this phase of the adolescence, also characterized by the high incidence of injuries, a highly vulnerable group of athletes is found, worthy of great attention by the professionals of health and sports. Therefore, the present study aims to quantify the occurrence of ankle sprains in soccer and futsal adolescent athletes and to verify some peculiarities of the injury in this age group.
The research was conducted in two soccer teams and four futsal teams of Brazil. A total of 128 adolescents were investigated, between 13 and 15 years of age. Among the 68 soccer athletes the average of age was 14.16 (±0.68), while in 60 of the futsal athletes the average found was of 14.11 years (±0.67). The general average of age among all the 128 participants of the research was 14.14 (±0.67).
The procedure used for the accomplishment of the present study consisted of individual interviews with each athlete. A closed-ended questionnaire was used as base for these interviews (Figure 1), being filled out by a single interviewer. All of the athletes received the information about the questions equally, with eventual doubts being cleared by the interviewer. None of the interviewees presented level of insufficient understanding that would exclude him from the study. The collection of data happened in schedules previous to the trainings, in the respective involved clubs.
Besides the identification data (name, age, club, category and tactical position), the following aspects were approached: training load, dominant lower limb, record of ankle sprains, sprain type, occurrence situation, injury mechanism, treatment received, recurrences and possible symptoms due to the injury. Was investigate just the injuries occurred after 10 years old with the objective of quantify the occurrence index of ankle sprains in the period where the teenagers are passing, on average, by the fast pubertal growth.
A descriptive statistical analysis was conducted, where the obtained data was expressed in percentile values for comparison among the groups and analyzed as for statistical significance, when pertinent, through the t-student test with significance level of p<0.05.
Before the research, the volunteers and their parental guardians were informed of the procedures of the study through a release of liability form stating that there would not be any remuneration, that the study didn’t offer risks for their health, that the participants could give up the participation when they wanted to and that their personal data would be maintained in absolute secrecy. After the explanations, the parental guardian and participant signed the release of liability form. The study was submitted and approved by an Ethics and Research Committee (protocol number H140/CEP/2006).
Table 1 shows the percentage of injured athletes in each modality, as well as the relationship between the dominance and the incidence of the injury and the classification of the sprains (inversion or eversion).
The injury mechanism was determined by the athletes’ report, being divided in the following items: struggle for ball on the ground; ball carrying; ball in the air (in this case, the landing); kicking/passing and alone without ball. Table 2 demonstrates the data regarding the two modalities as for the injury mechanism.
The situation in which the sprains happened was divided in: training, match, informal game (practice of the sport out of the club) and others (not related to the practice of the sport). The data can be seen in Table 3.
The treatment for the cases of ankle sprain was also evaluated, with the following items being scored in agreement with the athletes’ report. It was found that in 93.47% of the cases, there was need of removal of the athlete from the sporting activities for a certain period of time. Immobilizations of any type (plaster, brace, cast, bandaging, etc.) were done in 19.65% of the cases. The athlete had access to the physiotherapeutic treatment in 13.04% of the sprains and, in any approached case, they opted for surgical intervention.
The recurrences (sprain of the same ankle at least twice) were present in 10% of the soccer players and in 31.81% of the futsal players. In the total, 21.43% of the athletes with sprain record had recurrences.
The presence of usual symptoms caused by the ankle sprain was evaluated. Theses symptoms were described to all the participants as cases of pain, instability (sensation of slack ankle), insecurity and/or limps. Among the interviewed soccer players, 20% present current symptoms. In the futsal players, that average rises to 31.81%. In general terms, out of the 42 athletes that already had ankle sprains, 26.19% (11 athletes) complain about the presence of current symptoms in the injured ankle.
The average of age presented by the youths of both modalities didn’t present any statistically significant difference (p>0.05), which allows us to conclude that the difference between the incidence of the injury in soccer athletes (14.16 years) and futsal (14.11 years) was not related to their age.
The numbers of the research prove that ankle sprains possess a considerable incidence in adolescent athletes of both soccer (29.41%) and futsal (36.66%). However, a comparison with the literature cannot be established because it sees the percentage of ankle sprains in relation to the total of injuries, while the present study approaches the percentage of athletes that already had this type of injury.
As for the classification of the sprains, the data agree with the literature: 91.3% of sprains in inversion and 8.7% of sprains in eversion. Sheth et al.6 affirm that the inversions go from 85% to 90%. These numbers seem to prove what some authors9,20 mention regarding the large predisposition of the lateral area to have sprains due to the following factors: at a middle level, the strong deltoid ligament provides greater stability, along with the lateral malleolus that limits the eversion movement; laterally the ligaments present insufficient resistance when facing the demands to the mechanism of inversion of the ankle resulted from the sport.
Most of the ankle sprains happened in struggles for ball possession on the ground, making this mechanism responsible for 34.14% of the total of injuries. Those percentages can be related to the discoveries of Junge et al.21, that show that the majority (73%) of the injuries of soccer are due to physical contact among the athletes. Emery et al.19 also found, by evaluating athletes between 12 and 18 years, that most of the injuries (46.2%) is related to the contact among athletes. This prevalence of the sprain caused by physical contact can probably be explained by all the transformation that both futsal and soccer are suffering, where the athletes’ physical preparation and the opponent’s strong defense are prioritized more and more by the teams of all of ages.
The division by modality and, consequently, the division by tactical positions, loses credibility for the fact that the so-called “informal games” were the largest responsible for the injuries, totaling 43.48%. In this item any matches played out of the sporting club were included as, for instance, scholar matches, physical education classes, matches among friends, in the neighborhood block, on the beach, on the street, etc. Those informal games are characterized exactly by the absence of the official rules of soccer or futsal modalities. They can be played by a varied number of players (not always the same number in the two teams), in fields of different surfaces (courts, asphalt, sand, paved streets, etc.), with non-official balls, without characterization of the tactical positions, without a coach, without a referee, etc. Finally, the informal game is characterized by being unique in each place and every time that is played.
Not being able to study each case in depth in those conditions, the odds are increased in the division by modality. However, that is the reality of the interviewed players; before being athletes, they are teenagers that enjoy and need that social interaction out of the atmosphere of trainings and games of the club. The results are still accurate when showing the incidence of ankle sprains in practicing adolescents of the most popular “ball game” of the world.
Besides the informal games, the injuries happened in 32.61% of the cases during trainings, in 13.04% of the cases in matches and in 10.87% of the cases in activities not related to the sport. It would be interesting to gather data regarding the time during which the athlete is exposed to trainings and matches in order to have a trustworthy reference for comparison about the risk of injuries in each situation. There are still various aspects to be observed in that item: trainings happen from two to five times a week, while in that age one match is played per week; there are several types of trainings (collective, physical, technical, tactical, bodybuilding) that facilitate larger or smaller risk of sprain mechanisms; By being the titular player or staying on the bench, some athletes are more active than others, increasing their time of exposure; the competition level between game and training, and even among games of different importance (for instance, a game of the initial or final phase of a championship), could also influence the risk of injury.
Still regarding the occurrence situation, by comparing the modalities it can be noticed that while in soccer most of the injuries (45.45%) happened in trainings, in futsal the informal games were the largest responsible for the ankle sprains (50%). This fact can be explained by the training load (time of exposure) of each modality: soccer players train five times a week, while the futsal players play from two to three times weekly. Besides, it is suggested that soccer players have a lesser incidence in informal games because they be more adapted to irregular fields, as the soccer field itself if compared to the futsal court.
The question of each athlete’s dominant foot and the affected ankle was studied. Of the total of athletes with a sprain record, the dominant lower limb ankle was injured in 59.52% of the cases, the non-dominant in 30.96% and 9.52% presented bilateral sprain. In other words, except for the cases of injury on both ankles, almost twice as many athletes injured the dominant ankle in relation to those that injured the non-dominant. Ekstrand and Gillquist22, analyzing soccer athletes, also found that most of the ankle sprains happens in the athletes’ dominant limb.
Theoretically, the dominant limb presents better motor coordination (and proprioception) than the non-dominant, something that would lead us to assume that this would present smaller incidence of sprains. However, it is suggested that these numbers can be explained in the following way: the dominant limb is the one that performs better when kicking, being used in that function most of the time, which, consequently, makes the non-dominant limb provide a support function. This fact, repeated daily in trainings, matches and informal games would create a pattern, so that the dominant limb would “specialize” in kicking only and the non-dominant in giving support. This way, the dominant limb would become less effective than the non-dominant when it was demanded as a support foot, precisely the mechanism of the great majority of the ankle sprains3. This fact comes to emphasize the importance of training both feet, because this enabled to not only prevent injuries, but also maintain the technical benefit already known.
The bilateral development of abilities is an important aspect of the training process, unfortunately, neglected in most of the sporting centers23,24. Getchell and Whitall25 says that all of the children and young adults can develop an adaptation of motor coordination on both sides of the body, and the more earlier the encouragement for such, the better.
Stasinopoulos26 affirms that improvements in the technique can be an important prevention measure, and should be taught by the coaches. This author mentions works of Ekstrand and Tropp27, who got to reduce the incidence of ankle sprains in amateur soccer athletes with a program of specific technical training.
Bahr et al.28 inserted in a group of amateur volleyball athletes a prevention program joining specific technical training and proprioceptive training. As a result, they obtained a reduction of 50% in the incidence of ankle sprains.
A total of 21.43% of the athletes presented recurrent ankle sprains at least once. That data can be related with Thacker et al.13, who affirm that the most common risk factor of ankle sprains in the sports is the previous record of this injury.
The matter of current symptoms was described to all the participants as pain episodes, instability (feeling of slack ankle), insecurity and/or limps. For the present aspect, it was found that 26.19% of the athletes have these symptoms on the ankles with a previous sprain record, not being specified how long ago each injury had happened. Our discoveries corroborate with Saunders11, who says that symptoms as pain and instability are among 20% to 50% of the cases of ankle sprains.
Both recurrences and current symptoms can be related to the treatment received by the athletes after the episodes of ankle sprain. The present study didn’t have resources to identify the degree of seriousness of such sprains. However, the treatment received by the youths was analyzed generically per treatment modalities carried out in each case.
It was verified that in 93.47% the removal from the sporting activities was necessary. The number of cases in which the removal was due to professional recommendation or due to the athlete’s inability to perform was not observed. In 19.56% of the cases professionals of health intervened immobilizing the athlete’s ankles with casts, plaster, brace or simple bandaging. Physiotherapeutic treatment was necessary for only 13.04% of the injured athletes while surgical treatment was not observed any in case.
Of the total of athletes with recurrences of ankle sprain, 88.89% didn’t undergo physiotherapy. As for the athletes with the presence of current symptoms on the injured ankle, 81.82% didn’t undergo physiotherapy either. Among the athletes that did it, 50% didn’t have recurrent symptoms, while 33.33% presented subsequent symptoms to sprain and 16.66% incurred new sprain.
The study didn’t approach which modalities were used in these athletes’ treatments either. However, those data suggest that the physiotherapeutic treatment is effective in rebuilding the integrity of the injured ankle, working as a treatment technique and prevention of recurrences and/or possible current sprain symptoms, ratifying what had already been described by Safran et al.29, and Mattacola and Dwyer30.
The conclusion is that this research could prove quantitatively how much ankle sprains may affect teenager soccer and futsal players. These data should serve as resource to make the professionals that work in the area more aware of the need of treatment and the prevention in those cases. Besides, one more outstanding difference could be observed among the studies carried out with professional athletes (that constitute most of the researches in the area) and with adolescents who, besides their sporting activity in the club also have a parallel life full of activities where they increase the situations of possible injuries.
However, the main conclusion of this study is the verification of the need of conducting more researches with those individuals and their particularities. If, for instance, 32.81% of the athletes cannot go through puberty without having an ankle sprain, and of these 26.19% remain with clinical symptoms after the sprain episode, how many will be able to reach the senior category, becoming soccer or futsal professionals, in perfect physical conditions? Another question: how many might not have reached their objectives for having their performance limited by those injuries? Finally, how much can that high index of injuries in that age group (know to be a transition period), influence in a young athlete’s life? All those questions should serve as motivation so that new studies are done in order to provide better conditions, either in the sense of prevention or treatment, for those adolescents to be able to carry out their sports at their best of capacity and physical integrity.
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