Registered Nurses' Association of Ontario

Nursing Best Practice Guidelines

Use of the Semmes-Weinstein Monofilament

Directions for use of Semmes – Weinstein Monofilament

  1. Assess integrity of monofilament (no bends/breaks).
  2. Show the monofilament to the client. Place the end of the monofilament on his/her hand or arm to show that the testing procedure will not hurt.
  3. Ask the client to turn his/her head and close his/her eyes or look at the ceiling.
  4. Hold the monofilament perpendicular to the skin.


  1. Place the end of the monofilament on the sole of the foot. Ask the patient to say ‘yes’ when he/she feels you touching his/her foot with the monofilament. DO NOT ASK THE PATIENT, “did you feel that?” If the patient does not say ‘yes’ when you touch a given testing site, continue on to another site. When you have completed the sequence RETEST the area(s) where the patient did not feel monofilament.
  2. Push the monofilament until it bends, then hold for 1-3 seconds.
  3. Lift the monofilament from the skin. Do not brush or slide along the skin.
  4. Repeat the sequence randomly at each testing site on the foot (see pictures below).

Sites on the sole of the foot for monofilament testing
Loss of protective sensation = absent sensation at one or more sites.



  • Apply only to intact skin. Avoid calluses, ulcerated or scarred areas. DO NOT use a rapid or tapping movement.
  • If the monofilament accidentally slides along the skin, retest that area later in the testing sequence.
  • Store the monofilament according to the manufacturer’s instructions.
  • Clean the monofilament according to agency infection control protocols.