Final answer:
The hip flexors, such as the iliopsoas group, and the gluteus maximus have an antagonistic relationship during hip extension, with the hip flexors relaxing to allow the gluteus maximus to contract and extend the hip.
Step-by-step explanation:
The association of the hip flexors with the gluteus maximus during hip extension is characterized by an antagonistic relationship. When the gluteus maximus, which is the largest gluteal muscle, contracts, it extends the femur at the hip joint. This action is opposite to that of the hip flexors, such as the iliopsoas group, which includes the psoas major and iliacus muscles. These hip flexors are actively engaged during hip flexion, where they bring the thigh closer to the torso. During hip extension, the hip flexors are relaxed to allow the action of the gluteus maximus.
Moreover, the iliopsoas, being a prime mover of hip flexion, must lengthen or stretch while the gluteus maximus contracts to extend the hip. This coordinated movement ensures proper locomotion and balance during activities like walking or running. Therefore, a functional synergy exists where these muscle groups work in opposition to control movement at the hip joint.