Which abdominal muscle is the deepest of the four?

The transverse abdominus is the deepest of the four major abdominal muscle groups. It plays a crucial role in core stability and maintaining internal abdominal pressure. This muscle wraps around the torso like a corset, providing support for the spine and helping to stabilize the pelvis and lower back during various movements.

By being positioned beneath the other abdominal muscles, such as the rectus abdominus, internal obliques, and external obliques, the transverse abdominus helps to create a solid foundation for the body's movements. This makes it key in activities that require stability and strength, especially in exercises targeting the core.

The rectus abdominus is the most visible muscle, primarily involved in flexing the spine. The external and internal obliques are positioned on either side of the rectus and are involved in rotational movements and lateral flexion, but none provide the same foundational function as the transverse abdominus. This distinction reinforces the importance of the transverse abdominus in overall core health and function.