Small Yet Significant - Reflex Hammer

Overview

More than 130 years since its adaptation into neurology — a simple rubber knob with a handle remains one of medicine's most essential tools. I'm obviously referring to the easy-to-use reflex hammer.

A reflex hammer is an important medical device that we use to assess deep tendon reflexes (DTR). Deep tendon reflex examination and evaluation helps us to discover underlying peripheral and/or central nervous system dysfunction and evaluate the impact of observed abnormalities on the individual's activities of daily life. Additionally, one of the earliest objective clinical findings that might spot the early stages of a nervous system illness may be the clinical evaluation of deep tendon reflexes.?

Types of Hammers

While there are many other types of reflex hammers available, the most popular are the Taylor or tomahawk style reflex hammer, the Queen Square or Babinski style reflex hammer, and the Buck reflex hammer. As the practice of testing the DTR became more popular, so did the invention of various percussion hammers. Early percussion hammers were too light and had inconsistencies. This made us realize that an ideal instrument should be heavier in order to allow quick but powerful percussion without causing pain and impacting the tendon over a vast surface.

The hammers that had been rebuilt were heavier, and some included a handle and a sharp tip to test cutaneous responses, a ruler along the handle, and a pin, brush, or other item to assess feelings. To maximize their efficacy, certain hammers are equipped with a long, flexible handle. Tendons were most effectively struck directly, resulting in the creation of softer rubber impacting surfaces and a more sophisticated method.

Deep Tendon Reflex

Deep tendon reflex testing involves striking a tendon or muscle with a reflex hammer to elicit a reflexive contraction of that same muscle. Things that should be kept in consideration while performing DTR with reflex hammers are as follows:

1. Force of the stimulus must be strong enough to cause a reaction and must be maintained throughout time to allow for a repeatable response.

2. Usually, enough force may be obtained by letting a weighted or Queen Square reflex hammer fall by gravity from a distance of 10 to 12 cm.

3. Reflex hammers of the Taylor or Tomahawk style, which are lighter and unweighted, can be used to apply adequate power by swinging them freely between the thumb and forefinger and arcing the wrist and hammer in a 45 to 60-degree arc.

4. To elicit a clear and consistent reaction, the use of a minimum amount of power is necessary.

Some reflexes are easily evoked by striking the muscle directly with the reflex hammer, whereas others are easily aroused by striking the tendon that connects the muscle. In certain cases, the clinician may insert their finger between the hammer and a muscle or tendon (such as the brachioradialis, biceps, or adductor) to absorb force and/or palpate a reaction that would be hidden from view. The reflex hammer's contacting surface (i.e., its broad or tiny tip) should be matched by the medical professional to the size of the tendon or muscle being examined.

When testing the core reflexes and muscle stretches of the body we generally evaluate the health of the central and peripheral nervous systems. It enables us to keep an eye out for underactive or overactive reflexive responses. An abnormal reflexive response can be a warning sign of an underlying disease in the brain or spinal cord.

Conclusion

In this digital era of medicine, we have lot of technically exhausting instruments made to ease the workload of doctors and to be comfortable for the patients, but, nothing comes close to this humble hammer which has got its way to the neurology kit and still stands irreplaceable. When looked from the angle of cost/benefit I’m very positive that no advanced technology will ever match the diagnostic capacity of this simple knob.