What is the primary muscle involved in executing a proper squat?

The primary muscle involved in executing a proper squat is the gluteus maximus. This muscle plays a crucial role in hip extension, which is a key action performed during the squat. When descending into a squat, the gluteus maximus is activated to control the movement, and as you push back up to a standing position, this muscle is primarily responsible for extending the hips.

While the quadriceps and hamstrings also work during the squat, particularly at the knee joint, they do not contribute as significantly to the hip movement as the gluteus maximus does. The quadriceps are more engaged in the lowering phase and stabilization of the knees, but the gluteus maximus is essential for the power and force needed to rise back up. The deltoids, on the other hand, are not involved in this movement as they primarily function to move the shoulder joints, which are not directly engaged in the action of squatting.

This emphasizes the functional importance of the gluteus maximus in squats, making it the correct answer for identifying the primary muscle involved in this exercise.