How many muscles compose the abdominal wall that fill the space between the ribcage and pelvis?

The abdominal wall is comprised of four main muscle groups that work together to provide stability, support, and movement for the torso. These muscles include the external oblique, internal oblique, rectus abdominis, and transversus abdominis. Each of these muscles plays a crucial role in abdominal function.

The external oblique is the largest and most superficial of the abdominal muscles, helping with the rotation and flexion of the trunk. The internal oblique lies just beneath the external oblique and also aids in twisting and bending the torso. The rectus abdominis, commonly referred to as the "abs," is responsible for flexing the spine and is crucial for maintaining posture. Finally, the transversus abdominis acts like a natural weight belt, providing core stability and protection to the internal organs.

Understanding the composition of the abdominal wall is vital for designing effective exercise programs that enhance core strength and stability in group fitness settings.