Courtesy of Godoy Medical Forensics
An abrasion is a scrape from friction between the skin and another surface. The surface does not necessarily need to be hard, but the softer it is, the more friction is needed. An example of hard surface abrasions are road rash from motor vehicle accidents, where the skin is dragged one direction across the pavement. An example of soft surface abrasion would be from a shoelace tied around a wrist—the movement of the wrist in the attempt to liberate from the shoelace would cause ligature marks, even if the shoelace itself is a soft material. We also see abrasions from cervical collars applied by emergency personnel.
A laceration is from blunt force trauma where the impact causes the skin to split apart. It is recognized by an irregular wound edge. Tissues that are “bridging” the two sides together are also commonly seen. The wound edges in the image to the left are irregular, and the arrows point to bridging tissues, indicating it is a laceration from blunt force trauma.
Cut/Incision: Sharp Object
Cuts, or incisions, are wounds made by sharp objects. Incisions are most commonly used in reference to medical procedures. Cuts are more commonly used when an object, such as a knife or glass is used. Both cuts and incisions will have sharp wound edges and no bridging tissues. The wound edges in the image to the right are clean and there are no bridging tissues, indicating it is an incision or cut (in this case it is a surgical procedure).