Effects of the FIFA 11+ on Physical Performance and Injury Prevention in Female Futsal Players

According to the FIFA Medical Assessment and Research Center (F-MARC), consistent implementation of the "11+" program can lead to a 30-50% reduction in injuries. As the practice of soccer implies risk of injury, as well as F-MARC, considers that during training you should also include exercises to reduce the risk of injury. This warm-up program is intended to replace the traditional pre-workout warm-up. According to F-MARC, the key elements in injury prevention programs for footballers are core strength, neuromuscular control and balance, eccentric hamstring training, plyometrics and agility. The FIFA 11 has shown to improve physical performance and prevent injuries in male futsal players, however, this injury prevention program has not been tested in female futsal players.

With an experimental, randomized, controlled and multicenter study, the investigators intend to verify if the FIFA "11+" reduces injuries and produces changes in proprioception, static and dynamic balance, muscle strength, plyometric and agility results different from traditional warm-up/training programs used in futsal in 10 weeks.

The study will be carried out during the 2021/22 season, in the first division of the senior female national championships with a sample of 60 athletes. It is intended to implement a rigorous methodological process that allows solving the methodological problems of previous studies. The investigators will also characterize the injury profile of female futsal players in Portugal.

The present study intends to include all injuries sustained by players throughout the abovementioned time period. Injuries will be categorized according to type, location, mechanism of injury (traumatic or overuse), whether the injury was a recurrence onset, severity and if it was during training or match. Injury definition and classification will be set in accordance to the consensus agreement of injury definitions: slight (0 days), minimal (1-3 days), mild (4-7 days), moderate (8-28 days), severe (>28 days) and career ending. Injury-related data will follow the Consensus statement on injury definitions.

Anthropometric data will include, sex, age, height; weight, body mass index (BMI).Technical data will include lower limb dominance; players' playing position (keeper, lastman, winger, pivot and wing-pivot) age of initiation of futsal practice.

All analyses will be conducted on SPSS version 24.0 (SPSS Inc., Chicago, IL, USA). Normality of data distribution will be tested with the Shapiro-Wilk test. Descriptive statistics will be used to calculate the mean and standard deviation (SD). Injury incidence rates (number of injuries/1000 player-hours) will be calculated for all selected groups.

Dispersion in these variables was expressed as typical deviation and/or maximum and minimum values. Normality was studied using the Kolmogorov-Smirnoff test. Qualitative variables were expressed as absolute frequency and percentage. Quantitative variables were contrasted using the Kruskal-Wallis test for independent samples. Qualitative variables were analyzed using contingency tables and their statistical significance using Pearson's 12 test. All hypothesis contrasts performed were bilateral, taking a value of p<0.05 as statistically significant.