Latissimus dorsi muscle
| Latissimus dorsi muscle |
|---|
|
| origin |
| Spinous processes of the lowest 6 thoracic vertebrae as well as all lumbar vertebrae, thoracolumbar fascia , iliac bone ( labium externum of the iliac crest ), lowest 3 or 4 ribs , lower angle of the shoulder blade, back of the sacrum |
| approach |
| Front of the humerus ( Crista tuberculi minoris humeri ) |
| function |
| Withdrawal of the arm, lowering of the raised arm, adduction, internal rotation |
| Innervation |
| Thoracodorsal nerve |
| Spinal segments |
| C6-C8 |
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The latissimus dorsi muscle ( lat. For "broadest back muscle" or "very broad back muscle") or large back muscle lies along the entire length of the spine below the shoulder blade ( scapula ), whereby it is partly covered by the trapezius muscle , and ends at the upper edge of the pelvis .
The latissimus dorsi muscle has its origin in the trunk . It extends from the sacrum and iliac bone over the spinous processes of the lumbar and thoracic vertebrae through the armpit to the upper arm . It forms a striking pattern with the front sawtooth muscle . The latissimus dorsi muscle is the largest muscle in humans. On its inside pass artery thoracodorsalis , Vena thoracodorsalis and nerve thoracodorsalis .
Shares
In humans, the muscle has four parts:
- Pars vertebralis (part of the spine)
- Pars costalis (rib portion)
- Pars iliaca (part of the iliac bone)
- Pars scapularis (part of the shoulder blade)
function
The latissimus dorsi muscle turns the arm onto its back with the palm facing outwards, e.g. B. when the hand is brought to the buttocks. For this reason it is also called the “apron binder muscle” or, in an older German translation, “Arskratzermäuslein” ( lat. Musculus “little mouse”). “Scholarly muscle” is also used as a trivial name because it helps the professor from the old school to think deeply, to put his arm on his back and to be able to devote himself to his thoughts while walking leisurely. Its main effect is when the arms are raised, which can be lowered or the torso can be pulled up (e.g. when doing pull-ups ). This makes it the antagonist of the deltoid and trapezius muscles. Together with the teres major muscle , it forms the posterior axillary fold.
The muscle plays a synergistic role in the extension and sideways flexion of the lumbar spine. It helps with compressed exhalation (anterior fibers) and also acts as an auxiliary respiratory muscle during inhalation (posterior fibers).
As part of the auxiliary expiratory muscles , the latissimus dorsi ("cough muscle") supports the emptying of the lungs during heavy breathing.
The strength, size, and strength of this muscle can be developed through a variety of exercises. These are:
- Vertical pulling movements such as B. the lat pulldown and the chin-up. These exercises primarily serve the breadth of latissism dorsi. While a wide grip puts more strain on the upper muscle fibers, a tight grip works more on the lower fibers. An underhand grip results in greater biceps strain.
- Horizontal pulling movements such as B. Barbell rows, T-bar rows, and other rowing movements. The latter are primarily used for back density, i.e. the vertically running muscle fibers. The rhomboids and the rear part of the deltoid muscle are also trained.
- Coatings
Lifting under control helps reduce injuries.
Use in plastic surgery
Flaps of the latissimus dorsi muscle are used in plastic surgery as an autologous graft , especially in reconstructive surgery . They are used to cover defects , for example after severe injuries or tumor resections .
Individual evidence
- ^ Muscles Testing and Function With Posture and Pain 2005, ISBN 978-0-7817-4780-6 , p. 238.
- ↑ HS Pätsch: Possible uses of the latissimus dorsi flap. (PDF; 3.4 MB) Dissertation, University of Hamburg, 2008.