Jendrassik maneuver

Jendrassik maneuver is a medical procedure used to enhance the patellar reflex. The maneuver is named after the Hungarian physician Ernő Jendrassik, who first described the technique in the late 19th century.

Overview

The Jendrassik maneuver is a neurological examination technique used to distract the patient and thereby enhance certain tendon reflexes, most notably the patellar reflex, also known as the knee-jerk reflex. The technique involves the patient clenching their teeth or pulling their hands apart while the examiner tests the reflexes. This distraction allows for a more accurate assessment of the reflex being tested.

Procedure

The Jendrassik maneuver is performed as follows:

1. The patient is asked to sit or lie down with their legs hanging freely.
2. The examiner taps the patient's patellar tendon with a reflex hammer.
3. While the examiner is performing the tap, the patient is asked to perform a task that distracts them, such as clenching their teeth or pulling their hands apart.

The distraction task is intended to inhibit the patient's voluntary control over their muscles, allowing the reflex to be observed more accurately.

Clinical significance

The Jendrassik maneuver is primarily used to enhance the patellar reflex, but it can also be used to enhance other tendon reflexes. It is particularly useful in cases where the reflexes are diminished or difficult to elicit. The maneuver can help to distinguish between hyporeflexia (a condition characterized by below-normal reflexes) and areflexia (a complete absence of reflexes), which can aid in the diagnosis of various neurological conditions.

See also

• Deep tendon reflex
• Monosynaptic reflex
• Reflex arc