Why should the lateral sides of the infants heel be used for capillary puncture?

Because these is where the best capillary bed is located protecting the calcaneus from being damaged. For Infants under 6 months puncture at the lateral side of the heel is the best site since they’re fingers are so small. A heel stick is best recommended to use for this test.

The lateral sides of the infant’s heel is the preferred site for capillary puncture for it is the safest region for blood collection. If the center portion of the heel, toes and the arch of the foot is used for dermal puncture, it may cause injury to the nerves, tendons and cartilage.