Lateral ventral sacrocaudal muscle

Origin: Ventral surface of the body of the last lumbar vertebra and from the sacrum; the remainder arise from the ventral surfaces and roots of the transverse processes of the caudal vertebrae..

Insertion: Ventral lateral tubercle of the proximal end of the sixth through last caudal vertebrae.

Action: Flexion of the tail and occasionally lateral movement.

Nerve: Branches of the plexus caudalis ventralis.

Variation:

In equids, the lateral ventral sacrocaudal muscle is large and consists of long bundles ending in long tendons. It originates from the ventral surface of the body of the last sacral vertebra, the edge of the sacrotuberous ligament, and the base of the transverse processes of the first coccygeal vertebrae. The first tendon inserts at the sixth coccygeal vertebra. The following tendons split into two branches: a medial branch that inserts together with the tendons of the medial ventral sacrocaudal muscle, and a lateral branch that inserts on the rough areas replacing the transverse processes. From the fifth tendon onward, only a lateral branch remains, extending to the tip of the tail vertebrae