Ligamentum Flavum
Overview
Ligamentum Flava refers to the sum of actions of all of the ligamentum flavums in the body.
Anatomy
A single ligamentum flavum originates on the anterior lamina of a vertebral body and inserts onto the posterior lamina of the inferiorly adjacent vertebral body1.
The ligamentum flava form the posterior wall of the vertebral canal1.
The ligamentum flava in the lumbar spine are thicker than those in the thoracic and cervical spine since the lumbar spine experienes the most intervertebral flexion out of the 3 regions1.
Histology
Ligamentum flavum literally means “yellow ligament” due to its yellow pigment as a result of the high amounts of yellow elastic connective tissue1. The ligamentum flavum is made up of 80% elastin and only 20% collagen1. This provides the ligamentum flavum with highly elastic properties1.
Function
Since the ligamentum flavum is 80% elastin it results in an elastic tissue that excels at exerting a constant force at a moderate resistance1. The ligamentum flavum is taut in end-range spinal flexion where it functions to absorb some of the intervertebral compression1.
The ligamentum flavum increases in strain by ~35% from neutral spine to full flexion1.
Dysfunction
Extreme spinal flexion past full ROM can lead to a ligamentum flavum rupture1.
This position will not only place excess strain on the ligamentum flavum but also place high amounts of compression on the anterior aspect of the intervertebral disc