Hyperreflexia

Hyperreflexia is a classic sign of UMN disease but can be seen in other conditions such as thyrotoxicosis.
Hyperreflexia in one limb or in lower but not upper extremities can help localize lesions.

Neurology tutorial

Patient 2

A healthy student with no complaints with diffuse hyperreflexia. Medial Hamstring reflex assesses the L5 myotome, while the patellar is L4 and the Achilles is S1

Patellar Reflex

Medial Hamstring Reflex