Spinal Reflexes - Myotactic (Stretch) Reflexes

Spinal Reflexes – Myotactic (Stretch) Reflexes – Patellar Reflex
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Myotactic (Stretch) Reflexes

Patellar Reflex

•	The patellar reflex is an excellent example of the myotactic stretch reflex. The impulse is derived from the reflex hammer striking the patellar ligament. (to figure 5)
•	Anatomy and Physiology
	The motor component of this reflex arises from L4-L6 in the spinal cord which is the origin of the femoral nerve. The femoral nerve innervates the quadriceps muscle which is the effector muscle of this reflex.
•	Assessment
	The limb should be supported under the femur and have the stifle slightly flexed. The patellar ligament is struck. The expected response results in a single quick extension.