The Inception of a New Reflex Hammer without Re-inventing the Wheel

RFX Corporation was founded in 2017 around an idea, and now 2 years later we are launching our website and have officially received our first pre-order for the RFX Hammer. It has been quite the journey.


Before RFX hammer, doctors have used the generic reflex hammer for hundreds of years. A simple rubber headed hammer has taken many shapes and form factors over the years, but essentially hasn’t changed in its ability. A clinician takes a swing and hits the patient. Hopefully in the right spot and without causing injury!


As a medical student I found the reflex exam comical. The science was interesting, but watching my fellow students awkwardly hold a hammer and hit patients with it always seemed barbaric. As most know, a doctor uses the exam to asses for abnormal tendon reflexes, which are the response of the human body to a force on a deep tendon. If the body’s response is too strong or too weak, too brisk or too labile, then it's an indicator for neurologic abnormalities and further tests are needed.


The comical nature of the reflex exam in my mind increased when I looked at the literature. A systematic review of the reflex exam to assess a patient for lumbar radiculopathy (pinched nerves in the lower back, Tawa, et al.),  showed that if a patient has a normal lower extremity deep tendon reflex exam (i.e. reflexes at the knee, ankle, etc.), between 14 and 67% of the time the test is correct (Sensitivity). Luckily the test is a bit more useful when it shows an abnormal finding, which it usually gets correct between 60 and 93% of the time (Specificity).


Discussing this problem with other classmates prior to the inception of RFX Hammer, including Dr. Mathew Moore a family doctor now in Ontario, and engineer and co-founder Corey Reid, I was convinced by them that the medical community should be able to do better with their clinical exams.


With Corey’s critical help, we invented the RFX Hammer, a standard patient hitting device, but with the bonus of knowing how hard you are hitting your patients! This information changes the game, because instead of guessing whether or not you are conducting the reflex exam correctly, this tool confirms it. It improves consistency, skill, technique, and will hopefully prove to increase the dreaded sensitivity and specificity of the reflex examination.


The future of our fledgling company is unknown, but what is known is that medicine should not accept the status quo and continue to search for better ways. Humanity deserves no less. Join us and try the RFX Hammer. If interested in testing its accuracy, we’d love to hear from you too!


Written by: Dr. William Parker, Co-founder



Tawa, Nassib, et al. Accuracy of Clinical Neurological Examination in Diagnosing Lumbo-Sacral Radiculopathy: a Systematic Literature Review.” BMC Musculoskeletal Disorders, vol. 18, no. 1, 2017, doi:10.1186/s12891-016-1383-2.

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