Musculus corrugator supercilii
Small brow muscle drawing skin medially and downward. In horses, contributes to the worried expression noted in pain assessment (inner brow raiser action unit).
Origin: Frontal bone above the medial orbital rim
Insertion: Skin of the medial eyebrow region
Action: Draws the brow medially, creating vertical wrinkles above the eye
Innervation: Auriculopalpebral branch of facial nerve (CN VII)
Persistent brow tension is a validated sign of chronic pain or stress, scored in equine welfare assessments.
Persistent brow tension is a validated sign of chronic pain or stress, scored in equine welfare assessments. Signs include: Pronounced furrow above the inner eye; tense, worried expression at rest; often accompanies flared nostrils and stiff ears.
See the Corrugator Supercilii on our interactive 3D horse model. Open 3D Model