Lumbar Plexus

Authors

Affiliations

Nate Yomogida, PT, DPT

Doctor of Physical Therapy

B.S. in Kinesiology

Chloë Kerstein, PT, DPT

Doctor of Physical Therapy

B.A. in Neuroscience

Nerve	Roots	Motor Innervation	Cutaneous Innervation
Iliohypogastric N.	L1
Ilioinguinal N.	L1
Genitofemoral N.	L1, L2
Lateral Cutaneous Nerve of the Thigh	L2, L3
Obturator N.	L2, L3, L4
Femoral N.	L2, L3, L4

Direct Branches

Table 1: Direct Lumbar Plexus Muscular innervations

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

Dysfunction

“The lumbar plexus arises from higher levels (L1–L4) of the spinal cord and supplies muscles of the abdominal wall and anterior and medial thigh.”¹

References

1.

Gilroy AM, MacPherson BR, Wikenheiser JC, Voll MM, Wesker K, Schünke M, eds. Atlas of Anatomy. 4th ed. Thieme; 2020.