National Physical Therapy Examination (NPTE) Practice Exam

Which monofilament grade requires the least amount of force to be detected by a patient with protective sensation?

1. 3.61

2. 4.37

3. 5.07

4. 6.65

The correct answer is: 5.07

The grade of 3.61 monofilament requires the least amount of force to be detected by a patient with protective sensation. This particular grade exerts a force of approximately 1 gram, making it the most sensitive of the options listed. It is used to assess protective sensation, which is critical in lower extremity testing for patients who may be at risk for diabetic neuropathy or other conditions that impair sensation. Testing with the 3.61 monofilament is especially important because it can detect conditions where the patient might not be aware of injuries or pressure on their feet. Regularly screening with this monofilament helps in the early identification of sensory loss, allowing for timely intervention to prevent complications. In contrast, the 4.37 and higher grades, such as 5.07 and 6.65, require greater forces to be detected, which correlate with diminishing levels of sensitivity. While they are useful in assessing deeper levels of sensation or a complete lack of sensitivity (such as in the case of significant neuropathy), they are not ideal for evaluating the protective sensation threshold. Therefore, understanding the force requirements of different monofilament grades is essential for effective clinical assessment in patients at risk for sensory loss.