GLOSSARY

The multifidus is a deep muscle of the transversospinales group that runs the length of the spine from the sacrum to C2 but is bulkiest in the lumbar region, where it is a key stabiliser of the spine.
Its name comes from the Latin multi, meaning “many”, and findere, meaning “to split”, because it is divided into many bundles.

Attachments and Innervation

• Origin: the sacrum, posterior superior iliac spine, and the transverse and mammillary processes of the vertebrae.
• Insertion: the spinous processes of higher vertebrae, spanning 2–4 vertebrae.
• Nerve: the medial branch of the posterior ramus of each spinal nerve; each segment is supplied mainly by a single nerve.

Actions