How to Check Knee-Jerk?

To check the knee-jerk reflex, which is also known as the patellar reflex, you need a reflex hammer and a cooperative patient.

Checking the Knee-Jerk Reflex

Here's a step-by-step guide based on the provided reference material:

1. Positioning the Patient:

   • Have the patient sit with their legs dangling freely.
   • Ensure the leg muscles are relaxed to accurately assess the reflex.

2. Locating the Patellar Tendon:

   • Identify the patellar tendon located just below the kneecap.

3. Striking the Tendon:

   • Use the reflex hammer to gently but briskly tap the patellar tendon.
   • Observe the patient's leg for a response, such as a kick.
   • As the video demonstrates, you may need to repeat this action one or more times to be sure of the response.

4. Evaluating the Response

   • A normal response is the leg extending.
   • The video shows examples of a normal, good response.
   • The absence or a noticeably weaker or stronger response might indicate the need for further investigation.

Summary Table of Knee-Jerk Check

Step	Action	Purpose
1	Position patient with legs dangling	Ensures relaxed leg muscles for accurate reflex assessment
2	Locate patellar tendon below the kneecap	Target the correct spot for the reflex test
3	Gently tap tendon with reflex hammer	Elicit the knee-jerk response
4	Observe leg extension	Evaluate the response to check the reflex strength

Remember, proper technique is important to gain an accurate assessment of the patellar or knee-jerk reflex. The video example provides a good visual understanding of what a normal response looks like.