Glosaurus
Human Anatomy

Long thoracic nerve

A critical nerve that plays a pivotal role in shoulder movement and stability.
The long thoracic nerve is a branch of the brachial plexus, originating from the nerve roots of C5, C6, and C7. It innervates the serratus anterior muscle, which is essential for proper scapular function and arm elevation. Damage to this nerve can result in significant impairments in shoulder mechanics.
Terminologia Anatomica
nervus thoracicus longus
System
Nervous system
Function
The primary function of the long thoracic nerve is to provide motor innervation to the serratus anterior muscle, which is instrumental in the protraction and upward rotation of the scapula. This muscle allows the arm to be raised above shoulder level by stabilizing the scapula against the rib cage during arm movements. Optimal functioning of the long thoracic nerve is essential for various actions such as reaching overhead, pushing, and other upper limb activities. Furthermore, the serratus anterior plays a notable role in maintaining proper shoulder girdle alignment, which is crucial for preventing injuries and ensuring fluid movement of the arm. The interplay between the long thoracic nerve and the serratus anterior is fundamental not only for athletic performance but also for daily activities that require lifting or reaching.
Location
The long thoracic nerve courses down the lateral aspect of the thorax before reaching its target, the serratus anterior muscle. It runs along the surface of the upper and middle portions of the serratus anterior, lying just beneath the skin and often in close proximity to the ribs. This nerve can be particularly vulnerable to injury in certain positions, especially when the arm is elevated, as its path runs close to the ribs. Anatomically, it travels from the spinal cord down through the neck and axilla, making it an intricate component of the brachial plexus, and it is strategically positioned to facilitate its important role in shoulder stability and function.
Did You Know?
  • Injury to the long thoracic nerve often leads to a condition known as 'winged scapula,' where the shoulder blade protrudes outwards, making the shoulder appear unstable.
  • Athletes engaging in overhead sports, like swimming and tennis, must maintain strong serratus anterior muscles to prevent long thoracic nerve injury.
  • The long thoracic nerve can be compromised during surgical procedures in the axilla or due to trauma, requiring careful attention during such interventions.