Obliques
Musculi obliqui externus et internus abdominis
// Structure & location
According to OpenStax, the side wall of the abdomen consists of three flat layers of muscle. Outermost is the external oblique, whose fibres run down and inwards, like hands slid into trouser pockets. Underneath, the internal oblique crosses at a right angle, and the transversus abdominis lies deepest. At the front all three become sheet-like tendons that wrap the rectus abdominis.
// Function
The obliques rotate the trunk and bend it to the side. In a rotation, the external oblique of one side works with the internal oblique of the other side. The three layers with their different fibre directions also protect the abdominal organs and raise pressure inside the abdomen.
// For training & sport
- Pallof press and side planks train them as stabilisers against rotation and side bending.
- Cable woodchops train the rotation actively.
- Carrying a weight on one side (suitcase carry) forces them to stop you leaning over.
// Good to know
The transversus abdominis acts like a belt around the belly. It hardly moves anything, but compresses the abdomen, for example when breathing out forcefully.