Overview
This lecture explains how to assess the patellar deep tendon reflex, including correct technique, anatomical landmarks, and expected response.
Purpose & Anatomy
- The patellar reflex assesses neurological function of spinal cord levels L2 to L4.
- The patellar tendon is located just below the kneecap (patella).
Procedure Steps
- Have the patient extend their leg to help the patellar tendon become visible.
- Place your hand behind the patient’s knee for support and to promote relaxation.
- Locate the tendon below the kneecap.
- Tap the tendon briskly using a reflex hammer.
- Observe for extension (outward movement) of the lower leg as a normal response.
Key Terms & Definitions
- Patella — the kneecap bone at the front of the knee.
- Tendon — tough, fibrous tissue connecting muscles to bones.
- Patellar Reflex — automatic lower leg extension in response to tapping the patellar tendon, testing L2–L4 spinal levels.
- Deep Tendon Reflex (DTR) — an involuntary muscle contraction in response to a tendon tap, used to assess neurological function.
Action Items / Next Steps
- Practice performing patellar reflex assessment.
- Watch additional videos on how to check the other four deep tendon reflexes.