A knee hammer, also known as a reflex hammer, is used by medical professionals to test deep tendon reflexes. This helps in diagnosing neurological diseases and identifying abnormalities in the central or peripheral nervous system.
Here's a more detailed breakdown:
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Purpose: The primary function of a knee hammer is to elicit or assess reflexes.
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How it works: When the hammer strikes a tendon (like the patellar tendon below the kneecap), it stretches the muscle. This triggers a reflex arc, causing the muscle to contract and the leg to extend.
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Neurological Assessment: The presence, absence, or abnormal intensity of reflexes can indicate neurological problems. For example:
- Exaggerated reflexes may suggest an upper motor neuron lesion (e.g., stroke, spinal cord injury).
- Diminished or absent reflexes may suggest a lower motor neuron lesion (e.g., nerve damage, muscle disease).
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Part of a Neurological Exam: Reflex testing is a standard component of a comprehensive neurological examination, alongside tests for sensation, strength, coordination, and mental status.
Therefore, the knee hammer serves as a crucial diagnostic tool for assessing the integrity of the nervous system.
