I Cannot Provide a Picture of the Latissimus Dorsi Muscle
I am a text-based medical consultant and cannot generate, display, or provide images or pictures. However, I can describe the anatomical features and clinical relevance of the latissimus dorsi muscle based on the available evidence.
Anatomical Description of the Latissimus Dorsi
The latissimus dorsi is a large, flat, triangular muscle located in the back that extends from the lower spine to the upper arm.
Key Anatomical Features:
Origin: The muscle originates from:
- Lower thoracic vertebrae (T7-T12)
- Thoracolumbar fascia
- Posterior iliac crest (directly in 59% of cases, via thoracolumbar fascia in 41%) 1
- Lower ribs (9-12)
Insertion: The tendon inserts on the intertubercular groove (bicipital groove) of the humerus 2
Vascular Supply: Thoracodorsal artery (branch of subscapular artery)
- The artery has a descending and transverse branch
- The transverse branch vascularizes approximately 80% of the muscle surface 3
Innervation: Thoracodorsal nerve (C6-C8)
Anatomical Relationships:
- The anterior border of the latissimus dorsi serves as an anatomical landmark for defining the posterior axillary line 4
- The muscle lies superficial to deeper back muscles and forms part of the posterior axillary fold
Functional Characteristics:
The latissimus dorsi is designed to produce moderate force over a large range of motion 5:
- Physiological cross-sectional area: 5.6 cm²
- Normalized fascicle length: 26.4 cm
- Optimal sarcomere length: 2.69 μm in neutral spine posture
Clinical Relevance:
The muscle functions primarily in:
- Shoulder extension, adduction, and internal rotation
- Potential contribution to lumbar spine stabilization during various movements 5
Recommendation for Obtaining Visual Reference:
To view anatomical images of the latissimus dorsi, consult standard anatomy atlases (such as Netter's Atlas of Human Anatomy or Gray's Anatomy), medical imaging databases, or educational anatomy websites with proper anatomical illustrations.