The Spinal KineticsFeb 26, 2025 8:00:00 AM4 min read

Which Patients Need CRMA™? How to Identify and Diagnose Non-Disc Ligament Injuries

Introduction To Excessive Motion Testing

When you suspect a spinal injury in your patient—be it from an auto accident, a sports collision, or a fall—you’ll often order a variety of imaging tests to pinpoint the specific tissue damage. Many doctors already know when to order a CT scan (suspected fracture) or an MRI (suspected disc herniation). But what about the spinal ligaments that aren’t part of the discs? That’s where an excessive motion study—a CRMA™ (Computerized Radiographic Mensuration Analysis)—comes into play.
Below, we’ll break down the why, when, and how of ordering CRMA™ so you can ensure you’re delivering the most accurate and effective care for your patients with potential non-disc ligament injuries.

Understanding the Two Types of Connective Tissue

Disc Ligaments (23 in total)
- When these are damaged, an MRI will typically reveal a disc herniation.
Non-Disc Spinal Support Ligaments (197 in total)
- Damage to these ligaments often manifests as excessive motion on stress X-rays, which is what a CRMA™ captures.

If your patient hasn’t fractured a vertebra (ruling out CT) or shown obvious signs of disc herniation (ruling out the need for MRI), you’re still left with the possibility of non-disc ligament injury—and that requires an excessive motion study for a conclusive diagnosis.

Why Excessive Motion Matters

Spinal stability hinges on healthy ligaments. When they’re damaged, the spine can exhibit abnormal movement between vertebrae. This phenomenon, known as excessive motion, is the definitive imaging biomarker for non-disc ligament injuries.

CT or X-ray shows bone fractures/displacements.
MRI reveals herniations or soft tissue damage to the disc.
CRMA™ specifically measures and quantifies the spinal instability (excessive motion) that arises from ligament tears or stretches in non-disc support structures.

Key Point: If you suspect a spinal ligament injury in your patient—based on history, physical exam findings, or mechanism of injury—an excessive motion study is the only way to determine the severity of that ligament damage.

When Should You Order a CRMA™?

Ask yourself: Do I suspect a ligament injury? If the answer is yes, CRMA™ can clarify the extent. Here are some typical scenarios:

Auto Accidents
- Even seemingly mild crashes can result in serious ligament strain. If there’s pain, loss of motion, or neurological symptoms that don’t match with disc findings, a CRMA™ may reveal the hidden instability.
Whiplash-Associated Disorders
- Rapid neck flexion-extension can stretch or tear cervical ligaments. While MRI may rule out a major disc injury, CRMA™ can catch subtle excessive motion in the upper cervical region.
Suspected Upper Cervical Instability
- This is particularly common in cases that overlap with mild traumatic brain injury symptoms (e.g., headaches, dizziness, balance issues). The upper cervical ligaments are not disc-related; therefore, only an excessive motion test can confirm their integrity.
Persistent Spinal Pain Without Clear MRI Findings
- Not all spinal pain stems from disc or bone problems. When disc herniations and fractures are ruled out, CRMA™ can detect if the real culprit is ligament damage.

Remember: If you don’t order a CRMA™, it signals to insurers, attorneys, and even other clinicians that you don’t suspect ligament injury. Make sure that assumption is correct—these injuries are all too easy to miss.

What If the Patient Has Both Disc and Non-Disc Injuries?

It’s entirely possible for a patient to have a disc herniation and a non-disc ligament injury. In fact, disc injuries can occur alongside or because of the same compressive or shear forces that damage non-disc ligaments. An MRI will catch the disc herniation, but only an excessive motion test like CRMA™ will reveal whether there’s additional instability from ligament damage.

The Consequences of Missing Ligament Damage

Undiagnosed Instability
- Patients could be living with a level of instability severe enough to qualify for spinal fusion surgery, yet go untreated if never tested.
Inadequate Treatment Plans
- Physical therapy or chiropractic care might be beneficial, but fully addressing ligament damage requires targeted treatment. Without knowing the extent of the injury, providers risk under-treating the condition.
Chronic Pain and Long-Term Dysfunction
- If a patient goes without the correct diagnosis, they may continue to experience pain, reduced range of motion, and other lingering issues that can become permanent.
Overlapping Brain Injury Symptoms
- Particularly in upper cervical ligament injuries, patients may present with symptoms resembling mild traumatic brain injury (e.g., headaches, dizziness). Proper testing can confirm whether these symptoms originate from spinal instability.

Take-Home Message About Excessive Motion Testing

An excessive motion study (CRMA™) is indispensable for diagnosing non-disc ligament injuries. If there’s any reason to suspect ligament damage—based on the mechanism of injury, clinical signs, or patient complaints—don’t hesitate to order a CRMA™. It’s the only test that can quantify how badly those ligaments have been compromised, ensuring you deliver the most effective treatment plan.

In Short:

Fracture? Order CT.
Disc Herniation? Order MRI.
Suspected Non-Disc Ligament Damage? CRMA™ is your go-to diagnostic tool.

By combining CRMA™ findings with your clinical expertise, you’ll provide more precise, comprehensive care—helping patients recover faster and reducing the risk of chronic instability and pain.

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