| Latin | Musculus rectus abdominis |
|---|---|
| Origin |
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| Insertion |
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| Action |
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| Nerve | Thoracoabdominal nerves and subcostal nerve (T7–T12) |
| Name | Latin rectus, 'straight', and abdominis, 'of the abdomen' — its fibres run straight up and down. |
Palpation
- Client supine with a pillow or bolster under the knees to soften the abdomen.
- Stand at the side of the table and place the flat of your fingers just to one side of the midline, between the lower ribs and the pubic bone.
- Feel for a flat, firm band running up and down, about a hand's width across, with the linea alba (the midline tendon) on its inner edge.
- Ask the client to lift the head and shoulders slightly off the table; the muscle tightens under your hand and the tendinous bands that make the "six-pack" may become visible.
The rectus abdominis sits just under the skin and a layer of fascia on either side of the midline, from the pubic bone to the lower ribs. It is enclosed in a fibrous sheath (the rectus sheath) formed by the tendons of the External oblique, Internal oblique and Transversus abdominis. Clients who do a lot of sit-ups, or who sit hunched for long periods, often feel tightness here, which can pull the ribs down and restrict easy breathing.
Abdominal work uses gentle pressure. The abdomen has no bony protection over most of its area, so use broad, flat hands and slow strokes rather than deep, pointed pressure. When you stroke the whole abdomen, work clockwise (as you look down at the abdomen), which follows the path of the colon: up the client’s right side, across under the ribs, and down the client’s left side. Always get consent for abdominal work, check comfort often, and see Abdomen and chest — 15 min for draping and sequence.
The rectus abdominis is the main trunk flexor, so its opposites are the back extensors, Erector spinae and Multifidus. To tell it apart from the obliques, remember that its fibres run straight up and down, while the obliques run diagonally out at the sides of the waist.