Which muscles are included in the spinal flexors group?

The spinal flexors group primarily consists of muscles that perform flexion of the vertebral column. The rectus abdominis and internal obliques are key players in this group. The rectus abdominis runs along the front of the abdomen and primarily contributes to the flexion of the trunk, which draws the rib cage and pelvis together. This is essential for movements such as crunches or rolling exercises commonly performed in Pilates.

The internal obliques also play a significant role, as they assist in flexing the trunk as well as rotating it. Their positioning allows them to contribute effectively to movements that require both flexion and rotational stability.

In contrast, the other options consist of muscles associated with different actions. The erector spinae and multifidus focus on extension and stabilization of the spine. The hamstrings and gluteal muscles are primarily involved in hip extension and flexion of the knee, while the external oblique and iliocostalis are more about lateral flexion and extension of the spine rather than pure flexion. This distinction highlights why the rectus abdominis and internal oblique are correctly identified as components of the spinal flexors group.