Which muscle group supports flexion and rotation of the spine and runs vertically on the abdomen's anterior wall?

The rectus abdominis is the correct answer because it is a muscle group that is primarily responsible for flexing the spine and plays a role in rotation as well. This muscle runs vertically along the anterior wall of the abdomen, from the pubic bone up to the sternum. Its primary function is to pull the rib cage and pelvis together, which is critical during movements like crunches or sit-ups where spinal flexion occurs.

In the context of supporting rotation, while the rectus abdominis does contribute to some rotation, its main role is in flexion. This muscle is often referred to as the "six-pack" due to its segmented appearance in individuals with low body fat. It is important for core stability, posture, and supports various movements that involve bending forward or twisting the torso.

Other muscle groups mentioned also play significant roles in core stability and movement but do not match the specific characteristics of the rectus abdominis in terms of anatomy and function related to flexion and rotation on the anterior aspect of the abdomen. For instance, the obliques are indeed involved in rotation and lateral flexion but are not located vertically on the anterior wall. The transverse abdominis is crucial for core stability but primarily provides compression rather than