Two examples of early lancets. In the top lancet, the operator pulled back on “A” and, after positioning the lancet, released the lever “B” to make the capillary puncture. The bottom lancet accomplished a capillary puncture by the operator making a swift jab. As you will quickly discern, a capillary puncture using these devices was not a pleasant experience. The portion that made the capillary puncture was somewhat adjustable in both of these lancets. Even at their shortest, the length was still excessive. This was of particular concern when doing heel sticks on babies. The excessive length would cause the lancet to hit the baby’s heel bone, causing a heel spur to possibly form (see below). Fortunately, the way we now do heel sticks and the required length of lancets have eliminated this possibility.
A heel spur is a calcium deposit causing a bony protrusion on the underside of the heel bone. They are frequently associated with Plantar Fasciitis, a painful inflammation of the fibrous band of connective tissue that runs along the bottom of the foot.