L3 Vertebrae

Authors

Affiliations

Nate Yomogida, B.S., SPT

Doctor of Physical Therapy

B.S. in Kinesiology

Chloë Kerstein, B.S., SPT

Doctor of Physical Therapy

B.A. in Neuroscience

Muscles of the Iliac and Anterior femoral regions¹

Mobility

L3 in most cases serves as the peak or apex of the lumbar lordotic curve, and thus has the most mobility.

Malalignment

Due to the Psoas major’s proximal attachment from the anterior aspect of L3, an overactive Psoas major can result in an anterior translation of the vertebrae. The attachment at L3’s transverse process can also result in ipsilateral rotation of that segment.

Table 1: Psoas Major

Muscle	Origin	Insertion	Innervation	Action
Psoas Major	T12-L4 and associated IV discs L1-L5 TP	Lesser Trochanter	Lumbar Plexus Direct Br. L1 - L3	Hip: Flexion, ER L/S (unilateral contraction with femur fixed): I/L spine sidebend L/S (bilateral contraction): Raises trunk from supine position

References

1.

Gray H. Anatomy of the Human Body. 20th ed. (Lewis WH, ed.). Lea & Febiger; 1918. https://www.bartleby.com/107/