ankle jerk
Last reviewed 09/2023
The ankle jerk reflex is supplied by L5 and S1 nerve roots.
The procedure for eliciting the reflex is:
- position the patient's leg so that the knee is bent and the thigh is externally rotated
- let the tendon hammer fall onto the Achilles tendon
- an intact reflex will result in contraction of the gastrocnemius muscle and plantar flexion
If this reflex is not present then ask the patient to clasp and interlock his fingers together and then pull them hard apart. At this point, examine the reflex again.