Why the Multifidus Fails in Chronic Spinal Pain

Chronic low back pain affects millions of people worldwide. It is estimated that 80% of the population will experience low back pain in their lifetime, and the U.S. Centers for Disease Control and Prevention (CDC) has officially recognized the multifidus muscle as a major contributor to chronic spinal pain. This deep spinal muscle plays a critical role in stability, and it is often missed in traditional rehab.

At The Center for Total Back Care, we have long focused on why this muscle is so vulnerable to injury. The mechanism of the shutdown, and how spinal strength is measured, is covered in our guide to multifidus dysfunction.

What the multifidus does

The multifidus is a small muscle that runs along the spine. It works behind the scenes to stabilize the vertebrae during walking, sitting, bending, and turning.

Unlike the bigger muscles that create large movements, it has short fibers and a large cross-sectional area, so it is built for fine control. It spans only a few vertebral segments. It stays active to hold an upright posture through the day, and the realistic way to rest it is to lie down. That combination makes it prone to fatigue and injury at the segmental level.

What happens when the multifidus fails

Research shows that people with chronic back and neck pain often have:

• Weakness in the multifidus
• Poor endurance
• Fatty infiltration (atrophy)

When the multifidus is unable to do its job, the body recruits larger spinal muscles to take over. These muscles were not designed for stability. That extra work increases pressure on spinal joints, discs, and ligaments, and it can lead toward a herniated disc.

A weak multifidus can lead to instability, poor posture, muscle spasms, and chronic recurring pain.

Why multifidus dysfunction is so common

Healthy individuals show little to no dysfunction in the multifidus. In people with lower back pain, it is a different story.

The CDC now officially recognizes multifidus atrophy and fat replacement as a pathological cause of low back pain.

Factors that contribute to multifidus injury include:

1. Trauma such as a car accident or fall. Multifidus weakness is usually the residual pain that people experience following a car accident.
2. Sedentary lifestyles, including long hours sitting, looking at phones, or using screens.
3. Poor posture.
4. Driving for extended periods.
5. Lack of spinal-specific exercise.

Even after the pain goes away, the multifidus can be left in a weakened state, leaving the spine unprotected and vulnerable to future injuries.

Pain can improve while the muscle stays underactive. A familiar pattern is an injury, a period of relief, a return to normal activity, and then the pain comes back. Feeling better and being fully rehabilitated are not always the same thing.

Why general exercise is not enough

Active rehabilitation is essential for spinal pain, and most exercise routines still do not target the multifidus. Traditional gym workouts tend to activate the glutes, hamstrings, or hip flexors. Common floor exercises lack a way to isolate the deep spinal muscles, and standard machines often cannot progressively strengthen them without the hips taking over.

MedX for the lumbar and cervical spine

At The Center for Total Back Care we use MedX lumbar and cervical testing to compare spinal strength with age- and weight-matched norms, then rebuild it with the pelvis stabilized. When neck pain travels with this weakness, that evaluation includes the neck.

This approach identifies the weakness and rebuilds strength and endurance for daily activity and the demands of work.