Upper limb
Long thoracic nerve (Nerve of Bell)
Nervus thoracicus longus
- Origin
- Arises from the anterior rami of C5, C6, and C7 roots of the brachial plexus
- Insertion
- Descends along the lateral chest wall on the superficial surface of serratus anterior with the lateral thoracic artery
- Function
- Pure motor innervation to the serratus anterior muscle (protraction and upward rotation of the scapula)
- Innervation
- Pure motor supply (C5–C7)
- Movement & chain
- Glides over the lateral thoracic cage during scapulothoracic movement
- Palpation
- Not distinctly palpable through thoracic subcutaneous tissue
- Clinical
- Scapular winging (scapula alata: prominent medial border and inferior angle when pushing forward against resistance); susceptible to traction and surgical injury during axillary node dissection
- Segmental innervation
- C5, C6, C7 roots
- In clinical practice
- Diagnosed via the wall push-up test; protected meticulously during axillary lymphadenectomy and mastectomy
- Region in the model
- Upper limb