L5 myotome tests which movement?

L5 myotome tests which movement?

• A. Knee extension
• B. Great toe extension and hip abduction
• C. Elbow flexion and wrist extension
• D. Finger abduction and adduction

Answer: (B)

L5 myotome is tested by movements that are primarily controlled by muscles innervated by the L5 nerve root. The most characteristic actions here are great toe extension (extensor hallucis longus) and hip abduction (gluteus medius). In a neuro exam, asking the patient to actively extend the big toe and to abduct the hip directly assesses the L5 motor function. Knee extension corresponds to L3-L4, elbow flexion and wrist extension to cervical roots around C6-C7, and finger abduction/adduction to T1. So the movement pair of great toe extension and hip abduction best matches the L5 myotome.

L5 myotome is tested by movements that are primarily controlled by muscles innervated by the L5 nerve root. The most characteristic actions here are great toe extension (extensor hallucis longus) and hip abduction (gluteus medius). In a neuro exam, asking the patient to actively extend the big toe and to abduct the hip directly assesses the L5 motor function. Knee extension corresponds to L3-L4, elbow flexion and wrist extension to cervical roots around C6-C7, and finger abduction/adduction to T1. So the movement pair of great toe extension and hip abduction best matches the L5 myotome.