increases the intra-abdominal pressure as in a Valsalva maneuver. It also performs ipsilateral (same side) side-bending and contralateral (opposite side) rotation: the right external oblique would side bend to the right and rotate to the left, and vice versa. The internal oblique muscle functions similarly except it rotates ipsilaterally. Society and culture Oblique strain The oblique strain is a common baseball injury, particularly in pitchers. In both batters and pitchers it can affect the contralateral (leading) side external oblique, or the trailing internal oblique. Training Crunches Side plank Sit-ups Additional images References External links Abdomen Muscles of the torso Spine flexors Spine lateral flexors Spine rotators