The BEST way to test if a patient has sufficient protective sensation in the foot to prevent skin breakdown is to use:

• A. Monofilaments and test areas exposed to high weight-bearing
• B. A feather and brush lightly over the bottom of the foot
• C. A sharp pin prick and test for a painful response
• D. A hot/cold discrimination test and test heat and cold tolerance

Answer: (A)

Testing protective sensation is about whether a person can feel pressure on the parts of the foot that bear weight. The best way to assess this is with a Semmes-Weinstein monofilament, which is designed to apply a defined amount of pressure when pressed against the skin. Applying this filament to weight-bearing plantar areas—such as the ball of the foot and the toes—targets the sites most at risk for skin breakdown if sensation is lost. If the patient perceives the filament, protective sensation is present; if not, there’s a significant risk for ulcers because the person may not notice painful or damaging pressures.

Other methods test different sensory modalities and aren’t as predictive for preventing skin breakdown. A feather or brush measures light touch but not the threshold for protective pressure. A sharp pin prick assesses pain sensation, which is not the same as the protective sensation needed to sense potentially injurious pressures. A hot/cold discrimination test checks temperature sense, also not the protective pressure sense used to guard against ulcers.