Assessment of Limb Imbalance in Professional Soccer Players

Although it has been found that soccer produces limb imbalance, it has not been rigorously determined how to evaluate it in soccer players or which low-cost tests are the most effective for its analysis. Therefore, the objective of this systematic review was to identify and examine the evidence and evaluations of limb imbalance produced in professional soccer players. A systematic search was conducted in three databases (PubMed, Web of Sciences, and Scopus) to identify relevant studies published before 23 May 2022. Of the 2364 studies identified initially, only 12 articles were included in the systematic review. The results revealed that injury risks can be detected in professional soccer players through the YBT (Y Balance Test). The PSLR (Passive Straight Leg Raise) test, as well as the evaluation of the ROM (range of motion) in movements of adduction and internal hip rotation, seem to be two reliable tests to detect imbalances in the flexibility of the extremities. The FMS (Functional Motion Screen) test is inversely related to the performance in jump tests; thus, its combination can help to detect asymmetries in power generation. Finally, strength assessment tests in soccer players can negatively alter the flexibility values of agonist/antagonist muscles. Therefore, it is advisable to monitor both strength and flexibility tests synergistically to obtain a comprehensive evaluation.