Main Page | See live article | Alphabetical index The ankle jerk reflex, also known as the Achilles reflex, occurs when the Achilles tendon is tapped while the foot is dorsi-flexed. A positive result would be the jerking of the foot towards its plantar surface. The achilles reflex checks if the s1 and 2 nerve roots are intact and could be indicative of sciatic nerve pathology. This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.