The purpose of the present investigation was twofold 1) To compare the hip and thigh muscular activity of professional soccer players when performing the isometric squat with and without controlled hip contraction; 2) To determine the muscular relationships that take place dining these methods of execution of the exercise. Methods: 11 healthy male professional soccer players, randomly performed three modalities of isometric squat at a 60 degrees knee flexion: conventional squat (SQ), squat with hip abduction contraction (SQ-ABD) and squat with hip adduction contraction (SQ-ADD), controlled at 70% of 1 maximum repetition. The activity of the gluteus medius (GM), tensor fasciae latae (TFL), vastus medialis (VM), vastus lateralis (VL), semitendinosus (ST) and biceps femoris (BF) was obtained through surface electromyography. Hip (GM/TFL), quadriceps (VM/VL) hamstrings (ST/BF), and hamstrings/quadriceps (H/Q) ratios were analyzed. Results: GM increases in SQ-ABD and SQ-ADD compared to SQ (p<.01). The TFL, VL, SM and BF muscles have significantly higher activity in SQ-ADD compared to SQ (p<.05). The VL, VM and BF muscles significantly increase their activity in SQ-ADD compared to SQ-ABD (p <0.05). GM/TFL, VM/VL and ST/BF do not show significant differences between the three isometric squat methods. The H/Q ratio was higher in SQ-ABD and SQ-ADD compared to SQ (p<.01). Conclusion: The squat with hip adduction contraction in a controlled manner increases the muscular activity of the hip and thigh. Performing this combined maneuver can have benefits in sports training and rehabilitation because it increases the H/Q ratio of soccer players.