The Hoffman test, also known as the Hoffman sign test, lets your doctor know whether there are compression — or pressure — problems in your spine near your neck. During this brief examination, your doctor evaluates the possibility of spinal cord compression caused by an upper neuron lesion or another underlying nerve condition such as cervical myelopathy. The test is based on how your hand's reflexes respond to a quick flick of a fingernail.
What Are the Hoffman Test and Hoffman's Sign?
The Hoffman test determines whether a person has spinal cord damage. During this quick test, you hold out one of your arms and open your palm facedown, extending your fingers in front of you. Your doctor will then flick your middle fingernail. This will determine your Hoffman's sign or reflex result, which is also known as:
- The digital reflex
- The snapping reflex
- Tromner’s sign
- Jakobsen’s sign
If your thumb or forefinger move after the doctor's flick, your Hoffman sign result is positive. This means that you have damage in the upper region of your cervical cord — the upper part of the spine near your neck. This damage can include upper neuron lesions — or wounds — because of cervical cord compression.
If you don't experience any movement after the flick, your Hoffman sign result is negative. Several studies indicate that up to 3% of people will have positive Hoffman sign results even though their spinal cord is normal.
Is the Hoffman Test Accurate?
The Hoffman test should only be used as an initial screening tool — not a gold standard — for diagnosing cervical cord compression. For a more thorough evaluation, your doctor will order a magnetic resonance imaging (MRI) test to better assess spinal cord damage.
While studies are mixed on the accuracy of the Hoffman sign test, there does seem to be a greater than 50% correlation between the results of the Hoffman test and MRI test results. This means that it can accurately predict cervical compression some of the time but should not be used as the only diagnostic tool.