THE EFFECT OF THE SQUAT EXERCISE ON ANTERIOR-POSTERIOR KNEE TRANSLATION IN PROFESSIONAL FOOTBALL PLAYERS

Although the squat exercise is considered essential for optimal athlet ic performance, controversy exists regarding the effect on knee stabil ity. The purpose of this prospective study was to determine the effect of squat exercises on in vivo knee joint stability of professional fo otball players. Thirty-two subjects with normal knees participated in a 21-week off-season training program. Subjects performed power squat exercises with barbell loads of 130% to 200% body weight twice weekly. Both knees of each subject were tested by a single examiner with a kn ee ligament arthrometer before the training program and at 12 and 21 w eeks. Passive displacements were recorded at 67, 89, and 133 N with th e knee at 30-degrees and 90-degrees of flexion. Active testing was per formed with the knee in the same positions. Student's paired t-tests w ere used to compare pre- and postexercise measures. For all subjects, no significant differences were found between pre- and postexercise re sults for active and passive tests. Of the 2440 measurements taken, on ly 8 demonstrated increased excursions greater than 2 mm. This study d emonstrates no significant increases in anterior-posterior tibiofemora l translation in athletes using the squat exercise as part of their of f-season training program.