Muscular System

Multifidus

Musculus multifidus

Overview

The multifidus is a deep segmental muscle that spans 2–4 vertebral segments. It originates from the articular and transverse processes of vertebrae and inserts on the spinous processes of vertebrae 2–4 segments cranially. Its actions include fine segmental stabilization of the spine, proprioceptive feedback, and extension of individual segments. The cervical portion (multifidus cervicis) performs the same function in the neck. It is innervated by the medial branches of the dorsal rami of the spinal nerves (segmental). Research has shown that multifidus atrophy is closely correlated with back pain and osseous spinal pathology. The atrophy can be ipsilateral to the site of pathology and can persist after the original pain resolves. Targeted rehabilitation (dynamic mobilization exercises, belly lifts, and other core work) can increase multifidus cross-sectional area. Ultrasound is used to assess size and symmetry.

Quick Answer: The most important deep spinal stabilizer muscle. It spans 2–4 vertebral segments and provides fine segmental stability and proprioceptive feedback. Atrophy is closely correlated with back pain and can be assessed with ultrasound.

Anatomical Details

Origin: Articular and transverse processes of vertebrae

Insertion: Spinous processes of vertebrae 2-4 segments cranially

Action: Fine segmental stabilization of the spine; proprioceptive feedback; extends individual segments

Innervation: Medial branches of dorsal rami of spinal nerves (segmental)

Clinical Significance

Multifidus atrophy and asymmetry are common findings in horses with back pain, kissing spines, or chronic lameness. Ultrasound can measure cross-sectional area and compare left and right sides. Rehabilitation focused on core stabilization is often recommended.

Common Conditions & Injuries

Multifidus atrophy from back pain

## Overview The multifidus muscles stabilize individual vertebral segments. Back pain causes rapid, segmental atrophy of these muscles that can persist even after the pain resolves, creating a cycle

Core rehabilitation target

## Overview Core rehabilitation targets the deep stabilizing muscles of the trunk and neck (including multifidus, abdominals, and thoracic sling musculature) to restore spinal stability, improve post

What Horse Owners Should Know

Reluctance to bend, hollow back, or poor engagement under saddle can involve the multifidus and other deep stabilizers. Have persistent back issues evaluated. Core exercises can help restore function.

Frequently Asked Questions

What is Multifidus atrophy from back pain in horses?

## Overview The multifidus muscles stabilize individual vertebral segments. Back pain causes rapid, segmental atrophy of these muscles that can persist even after the pain resolves, creating a cycle of instability and re-injury. Visible asymmetry or poor topline that does not respond to general exercise may be noted. ## What It Indicates Chronic or recent back pain leading to disuse of the deep spinal stabilizers. ## Diagnosis Ultrasound measurement of multifidus cross-sectional area, often asymmetric next to specific spinous processes. ## Treatment Targeted rehabilitation exercises that activate the multifidus, along with treatment of the original pain source. ## Recovery and Prognosis Muscle can be rebuilt with specific exercises, but recovery is slower than with general conditioning. ## Prevention Early treatment of back pain and inclusion of core-stability work. Signs include: visible or ultrasound-detected atrophy alongside specific spinous processes; poor topline unresponsive to general exercise; chronic back pain

What is Core rehabilitation target in horses?

## Overview Core rehabilitation targets the deep stabilizing muscles of the trunk and neck (including multifidus, abdominals, and thoracic sling musculature) to restore spinal stability, improve posture, and support recovery from back pain or limb injury. It is a therapeutic approach rather than a disease. ## Causes N/A (this is a care strategy). ## Diagnosis Assessment of posture, muscle development, and functional stability by a veterinarian or equine physiotherapist. ## Treatment Dynamic mobilization exercises, resistance-band work, baited stretches, and progressive core-strengthening under guidance. ## Recovery and Prognosis Most horses show improved posture and comfort with consistent work over weeks to months. ## Prevention Regular inclusion of core exercises in conditioning programs. Signs include: N/A (therapeutic target); associated findings may include poor topline, hollow back, or reduced spinal stability

What are the clinical concerns for the Multifidus?

Multifidus atrophy and asymmetry are common findings in horses with back pain, kissing spines, or chronic lameness. Ultrasound can measure cross-sectional area and compare left and right sides. Rehabilitation focused on core stabilization is often recommended.

What should horse owners know about the Multifidus?

Reluctance to bend, hollow back, or poor engagement under saddle can involve the multifidus and other deep stabilizers. Have persistent back issues evaluated. Core exercises can help restore function.

Explore This Structure in 3D

See the Multifidus on our interactive 3D horse model. Open 3D Model