How to Measure Wound Undermining

 Wound Undermining

Wound undermining occurs when the tissue under the wound edges becomes eroded, resulting in a pocket beneath the skin at the wound’s edge.

wound undermining wound care education

Undermining is measured by inserting a probe under the wound edge directed almost parallel to the wound surface until resistance is felt.  The amount of undermining is the distance from the probe tip to the point at which the probe is level with the wound edge. Clock terms are also used to identify the area of undermining.

Wound undermining is more commonly found in patients with pressure or neuropathic ulcers.

Because tunneling and undermining are not readily visible, all wounds must he thoroughly probed to identify the full extent of tissue destruction. Wounds presenting with tunnels or undermining heal more slowly than wounds without these characteristics.


  1. I’m a Register Nurse dedicate to wound treatment. I will like to know how to take care of ulcer with underminding.

    1. Hi Catherine, As an RN dedicated to treating wounds, I highly recommend wound care certification. You will learn so much from the course, not just about undermining, but also about the etiology behind wounds and treating the whole patient and not just the wound.

      The online interactive educational programs are convenient and will prepare you for the nationally accredited wound care certification exam provided by the American Board of Wound Management (ABWM). For more information about the ABWM exam eligibility requirements please visit:

      The following presentation provides a brief overview of our program:

      We also recommend reading the following article: The Importance of Formal Accredited Certification in Wound Care:

      For detailed information visit our wound care certification courses page, or contact us directly.
      For detailed information visit our wound care certification courses page, or contact us directly.

  2. A patient with a sacral ulcer. Has deep undermining. 6 cm at 1 o’clock. 2.5 cm from 3 – 9 o’clock. Doctor wants to treat with negative pressure but will not use foam to address undermining, either by packing it in the wound or on top by bolstering. Only by placing a small piece of foam in the opening only. Will the undermining heal this way?

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