The cremasteric reflex (Image 1) may be elicited by stroking along the thigh. Normally, the ipsilateral scrotum contracts. If there is bilateral absence of the cremasteric reflex, an upper motor neuron injury is suspected. Unilateral absence of the cremasteric reflex indicates a lower motor neuron lesion.

The L4 patella tendon (Image 2) and the S1 Achilles tendon (Image 3) reflexes are quite familiar.