A client has a lumbar puncture procedure. Which position should the client be placed in?

• A. Lateral (side) position with the knee and head flexed at an acute angle.
• B. Supine with the legs extended.
• C. Prone with the head rotated to the side.
• D. Seated upright with the back flexed.

Answer: (A)

Maximizing access to the subarachnoid space by widening the spaces between the lumbar vertebrae is what positioning for a lumbar puncture aims to achieve. Turning the patient onto the side with the knees drawn up to the chest and the head tucked toward the chest (a fetal, side-lying position) flexes the spine and straightens the canal, which opens the interlaminar spaces between vertebrae. This makes it easier to advance the needle into the subarachnoid space and reduces the chance of bone contact or nerve irritation. While other positions can be used in some settings, the side-lying, knee-and-head-flexed posture is the most effective for obtaining access safely and is commonly preferred.