Reflex hammer’s are useful metrics for assessing abnormalities in the central and peripheral nervous systems. Hyperreflexia, or heightened reflexes, is associated with problems of the former nervous system, while reduced reflex are associated with disorders of the latter. The stimulus power that was utilised to elicit the reaction has an impact on its amplitude, but though there have been attempts to measure the force necessary to elicit a response, the results are difficult to quantify and vary depending on the hammer used.

With the doctor holding the end of the Taylor hammer, the entire instrument is swung in an arc-like manner onto the affected tendon. Usually held perpendicular to the affected tendon, the Queen Square and Babinski hammers are passively swung onto the tendon with the help of gravity. 

The Jendrassik procedure, which entails interlocking flexed fingers to distract a patient and set off the reflex reaction, is another technique for emphasising reflexes. In situations of hyperreflexia, the doctor may tap the finger with a hammer while placing his finger on top of the tendon. Reflex hammers aren’t always required to cause hyperreflexia; in many cases, simply tapping the tendon with your fingers will do the trick.