What two muscles rotate the spine and help add pressure to abdomen?

The two primary muscles that rotate the spine and contribute to abdominal pressure are the external obliques and the internal obliques. The external obliques are located on the sides of the abdomen and facilitate trunk rotation, while the internal obliques lie beneath them and assist in the same motion. Both muscles work together to stabilize the core and increase intra-abdominal pressure during activities like lifting or twisting.