Abstract

Objective. To estimate the reliability of tests to measure the flexibility of the flexion and extension musculature of the knee according to the season, the age and the position of male footballers in the training area of a professional football club. Material and methods. Flexibility was measured by applying the Modified Thomas Test (MT Test) for quadriceps and the Modified Back-Saber Sit-and-Reach Test (MBS Test) for hamstrings. The reliability was estimated via the Cronbach’s α. Results. Both tests showed high estimations of reliability between seasons, by categories of players’ position and compared to the performance between the lower left and right member. Conclusions. Both tests can be applied in group sports, as in the training area of professional football clubs, especially in the prevention of sports injuries, since they have an accepted validity, show a high degree of reliability according to the study and have further characteristics such as low cost, easy application and the ability to measure a large number of people in brief periods of time.