Psoas minor innervation is from a branch of which spinal level?

Psoas minor innervation is from a branch of which spinal level?

• A. Branch of L2
• B. Ventral Rami L1-L2
• C. Branch of L1
• D. Branch of L3

Answer: (C)

Psoas minor is innervated by a small branch that arises from the ventral ramus of the first lumbar nerve (L1). This specific L1 branch, sometimes called the nerve to psoas minor, supplies the muscle when it is present. The distinction matters because psoas major has a broader innervation pattern (primarily L1-L3), whereas psoas minor relies on this single L1 source. That’s why the correct answer is a branch of L1. In individuals where the muscle is absent, there won’t be a corresponding innervation, but when it exists, the supply is tied specifically to L1 rather than L2 or a combined L1-L2 input.

Psoas minor is innervated by a small branch that arises from the ventral ramus of the first lumbar nerve (L1). This specific L1 branch, sometimes called the nerve to psoas minor, supplies the muscle when it is present. The distinction matters because psoas major has a broader innervation pattern (primarily L1-L3), whereas psoas minor relies on this single L1 source. That’s why the correct answer is a branch of L1. In individuals where the muscle is absent, there won’t be a corresponding innervation, but when it exists, the supply is tied specifically to L1 rather than L2 or a combined L1-L2 input.