Impact of the FIFA 11+ on the structure of select muscles in adolescent female soccer players

• There is a high risk of lower extremity injury in soccer.
• Injury prevention warm-up programs (i.e. FIFA11+) reduce soccer injuries.
• We compared the effect of varying levels of FIFA11 + exposure on trunk and leg muscles in soccer players.
• ≥15 FIFA11 + exercises/week over a 4-month season may result in beneficial abdominal wall adaptations.
• These beneficial changes may be best achieved with a balanced approach to the 11 + program.

ObjectivesTo determine the impact of an injury prevention program (FIFA11+) on the structure of select trunk and leg muscles in adolescent female soccer players.DesignExploratory analysis.SettingUniversity Sport Medicine Centre.Participants23 female soccer players (aged 14–16) recruited from a FIFA11 + implementation trial grouped by high and low 11 + exposure.Main outcomesPre and post-season sonographic measures of the rectus abdominis, external and internal oblique, transversus abdominis, inter-recti distance (IRD), lumbar multifidus, gluteus medius and minimus, and vastus medialis. Mean (95% confidence intervals; CI) were calculated for pre, post and pre-post season change of all parameters and univariate analyses used to compare groups (α = 0.001).ResultsBoth low (mean = 149 ± 9 exercises/year) and high (mean = 314 ± 15 exercises/year) 11 + exposure groups demonstrated significant post-season decreases in IRD at rest (p < 0.001) and during a leg lift (p < 0.001). No other between or within group differences existed.ConclusionsLevels of FIFA11 + exposure were not associated with differential changes in the morphology of investigated muscles. As the IRD of participants in both exposure groups decreased it is possible that the protective mechanism of the FIFA11 + may be associated with alterations in neuromuscular control that result in abdominal wall adaptations.