What is a facet joint?

Short answer: A facet joint is a small joint at the back of the spine. Each vertebra has a pair, one on each side, linking it to the vertebra above and below. Facet joints guide and limit how your spine bends and twists. When they're strained, stiff or inflamed, they're a common source of neck and back pain.

What is a facet joint and where are they?

Each level of your spine has three joints. At the front is the intervertebral disc, a tough, cushioning pad between the vertebral bodies. At the back are two facet joints, one on the left and one on the right. Together, these three form what's sometimes called the "three-joint complex".

The facet joints (also called zygapophyseal or "z-joints") are formed where small bony projections from one vertebra meet the vertebra below. Like your knee or knuckle, each one is a true synovial joint:

• the joint surfaces are covered with smooth cartilage
• a capsule wraps around the joint and holds lubricating fluid
• the capsule is well supplied with nerves, which is why these joints can be quite painful when irritated

Facet joints run all the way from the top of the neck to the base of the low back, where the last lumbar vertebra meets the sacrum.

What do facet joints do?

The disc carries most of the weight. The facet joints act more like guide rails. Their angle changes from region to region, which shapes how each part of your spine moves:

The facet joints also share load with the disc, especially when you lean backwards or stand for a long time with an increased low back curve. They sit right beside the openings where spinal nerves leave the spine, which is why a swollen or enlarged facet joint can sometimes contribute to a pinched nerve.

What does facet joint pain feel like?

Facet joint pain is a common type of mechanical neck and back pain. It often has some of these features:

• a deep, aching pain to one side of the spine, sometimes both
• pain that's worse leaning backwards, twisting or turning towards the sore side
• stiffness first thing in the morning or after sitting still, easing as you get moving
• pain that can refer into the buttock or upper thigh from the low back, or into the shoulder blade and the back of the head from the neck
• local tenderness over the joint

Pain referred from a facet joint usually doesn't travel below the knee or into the hand, and doesn't usually come with numbness or weakness. That's one of the ways we tell it apart from nerve root irritation.

What causes facet joint pain?

• Sudden strain: an awkward twist, lift or reach. A "locked" neck or back after a sudden movement often involves a facet joint.
• Sustained positions: long periods standing, or sitting with the head pushed forward, keep load on the same joints.
• Age-related change: over the years, facet cartilage can thin and the joints can stiffen, often alongside disc changes. This is very common and doesn't always cause pain.
• Injury: falls and car accidents, including whiplash, can strain the facet joint capsules in the neck.
• Repetitive extension and rotation: sports and jobs that involve lots of arching, twisting or working overhead.

Facet joints and the nervous system

Facet joints aren't just mechanical guide rails. They're part of your spine's sensory system. Their capsules carry nerve endings, and the deep muscles that cross each spinal level are packed with muscle spindles, sensors that tell your brain how that level is moving. Together they give your brain a detailed, moment-by-moment report on the position of your spine.

When a segment is strained or stiff, that report can change. In the current research model, pain or injury can alter how the brain controls the segment: the deep muscles tighten, the facet joints move less, and the brain gets thinner information back, which can keep the cycle going. Chiropractors call this a vertebral subluxation.¹

An adjustment is a quick, precise thrust to a specific segment, designed to send a burst of information from those deep tissues to the brain. Research has measured what happens next. One study found a single session changed how the brain's prefrontal cortex processed sensory information from the body.² Learn more about chiropractic and your nervous system.

How we approach this at MPCC

There's no single test that proves pain is coming from a facet joint, so a careful assessment matters. Your new patient appointment takes 30 to 40 minutes. We hear your story, take posture pictures, and do a thorough chiropractic, orthopaedic and neurological check of your spine, joints and nerves. We look at which movements provoke your pain, feel how each joint moves, and check the nerves so we can tell joint pain apart from nerve or disc irritation.

X-rays aren't routine. We only refer for them when your history and check point to them, and the imaging clinic we refer to bulk bills X-rays our chiropractors request.

At your report of findings appointment we explain what we found in plain English and what we'd do. Depending on your case, care may include specific chiropractic adjustments to restore movement in stiff joints, work on our flexion-distraction table for the low back, and exercises to take home. Read more about low back pain and neck pain.

Looking after your facet joints at home

• Keep moving. Gentle, regular movement helps joint fluid circulate and stiffness settle.
• Break up long periods of standing or sitting.
• Use heat or ice, whichever feels better, for 15 to 20 minutes at a time.
• Strengthen your trunk and hips. Our glute bridges are a good place to start.