A toddler is to have a lumbar puncture. Which positioning is appropriate?

• A. Place toddler in side-lying knee-chest position
• B. Place the toddler in prone position with head turned
• C. Seat the toddler upright on the parent's lap
• D. Place the toddler in supine with legs extended

Answer: (A)

The key idea is to position the child so the spaces between the lumbar vertebrae are widest and the spine is relaxed, making needle insertion easiest and safer. Placing a toddler in a side-lying position with the knees drawn up toward the chest (lateral decubitus) achieves this by maximally flexing the spine. That flexion opens the interlaminar spaces and aligns the spinal column for a smoother, more accurate needle path, while also helping the child stay still and comfortable during the procedure.

The other positions don’t provide the same access. A prone position with the head turned doesn’t optimize the lumbar interspaces and can complicate alignment and airway safety. Sitting upright on a parent’s lap may lead to movement and makes it harder to access the lumbar region. Lying on the back with legs extended reduces spinal flexion, narrowing the interspaces and hindering needle placement.