After my third EMG continued to point toward the C5-C6 area, I wanted to understand exactly what that meant.
Was the doctor saying my C5 nerve was damaged?
Was it the C6 nerve?
Could either one cause the pain around my shoulder blade, neck, shoulder, and arm?
The terminology becomes confusing because the name of a disc level and the name of a cervical nerve root are not always the same. A C5-C6 disc problem commonly affects the C6 nerve root, while a C4-C5 disc problem commonly affects the C5 nerve root.
C5 and C6 nerve pain symptoms can also overlap. Both may affect the shoulder, upper arm, elbow movement, and nearby muscles. Doctors usually compare the complete pattern of pain, weakness, numbness, reflexes, imaging, and EMG findings rather than identifying the nerve from one symptom.
The Quick Difference
C5 radiculopathy more commonly affects the shoulder and outer upper arm. It may cause weakness when raising or rotating the arm.
C6 radiculopathy often travels farther down the outer arm and forearm toward the thumb and index finger. It may weaken elbow bending and wrist extension.
Those are the classic patterns, but real people do not always follow the textbook.
Research summarized by the American Academy of Physical Medicine and Rehabilitation indicates that cervical pain patterns can vary significantly between patients. Some people do not experience the expected textbook distribution at all.
What Does Cervical Radiculopathy Mean?
Cervical radiculopathy occurs when a nerve root in the neck becomes compressed, inflamed, or otherwise irritated.
The American Academy of Orthopaedic Surgeons explains that cervical radiculopathy can cause pain that travels into the shoulder or arm along with numbness and muscle weakness.
Symptoms can include:
- Neck pain
- Shoulder-blade pain
- Shoulder pain
- Pain traveling down the arm
- Numbness or tingling
- Muscle weakness
- Reduced reflexes
- Pain that changes with neck or arm position
Not every person develops all these symptoms. Some people mainly experience pain, while others have weakness or numbness with surprisingly little pain.
Why a C5-C6 Disc Problem Usually Affects the C6 Nerve Root
This confused me for a long time.
I had the disc between my C5 and C6 vertebrae replaced. It would be reasonable to assume that the damaged nerve must therefore be called the C5-C6 nerve.
However, individual cervical nerve roots are usually identified by one number.
The C6 nerve root normally exits the spinal canal near the C5-C6 disc level. Because of that anatomy, narrowing or a herniated disc at C5-C6 commonly affects the C6 nerve root.
The C5 nerve root normally exits one level higher, near the C4-C5 disc.
The usual relationship
- C4-C5 disc level commonly affects the C5 nerve root.
- C5-C6 disc level commonly affects the C6 nerve root.
- C6-C7 disc level commonly affects the C7 nerve root.
This relationship is useful, but it does not diagnose an individual person. Bone spurs, narrowing in different locations, unusual anatomy, inflammation, and findings involving more than one level can change the pattern.
What C5 Nerve Pain Usually Feels Like
C5 radiculopathy often produces symptoms closer to the neck and shoulder than C6 radiculopathy.
Pain may be felt around:
- The side of the neck
- The upper shoulder
- The inner border of the shoulder blade
- The outer part of the upper arm
- The area near the deltoid muscle
The pain may not travel all the way into the hand. Some people with C5 radiculopathy have shoulder and upper-arm symptoms that resemble a rotator-cuff or other shoulder problem.
The American Academy of Physical Medicine and Rehabilitation describes the typical C5 pain pattern as involving the medial shoulder-blade border and lateral upper arm.
This interests me because pain around my left shoulder blade and upper back has been one of my most persistent symptoms.
What Weakness Can C5 Radiculopathy Cause?
C5 contributes to muscles that raise and rotate the arm at the shoulder.
Possible weakness may involve:
- Lifting the arm out to the side
- Raising the arm overhead
- Rotating the shoulder outward
- Stabilizing the shoulder joint
- Beginning certain reaching movements
The deltoid, supraspinatus, and infraspinatus muscles may be affected.
A person with significant C5 weakness may have difficulty lifting the arm even when the shoulder joint itself is structurally healthy.
That is one reason cervical radiculopathy may be mistaken for a shoulder injury.
What Numbness Can C5 Radiculopathy Cause?
C5 sensory changes are usually described around the outer shoulder and lateral upper arm.
Numbness in the thumb or index finger would fit the classic C6 pattern better than an isolated C5 pattern.
However, sensation patterns vary, and many people with cervical radiculopathy do not develop a perfectly outlined patch of numbness.
I do not think it is wise to trace one area of tingling on a diagram and declare that one nerve must be damaged. The pattern provides a clue, not a final answer.
What Reflex Can Change With C5 Radiculopathy?
Doctors may check the biceps and brachioradialis reflexes when evaluating the C5 and C6 nerve roots.
Some medical references associate C5 more closely with changes in the supinator or brachioradialis reflex, although reflex contributions overlap.
A reduced reflex may support the rest of the examination, but it does not diagnose a cervical nerve-root problem by itself.
Reflexes can naturally differ between people. The doctor may be more interested in a clear difference between the left and right sides.
What C6 Nerve Pain Usually Feels Like
C6 radiculopathy often produces symptoms that travel farther down the arm.
The classic C6 pain path can include:
- The neck
- The shoulder or shoulder-blade region
- The outer upper arm
- The outer forearm
- The thumb
- The index finger
Pain may feel sharp, burning, aching, electrical, or like a deep pulling sensation.
Not everyone experiences a clean line running from the neck to the thumb. The pain may stop at the shoulder, appear mainly in the forearm, or involve several separated areas.
Because I had surgery at the C5-C6 disc level, the C6 nerve root is an important part of the discussion. Still, I want my doctor to explain exactly which muscles were abnormal instead of assuming the affected nerve from the surgical level alone.
What Weakness Can C6 Radiculopathy Cause?
C6 contributes to several movements involving the shoulder, elbow, forearm, and wrist.
Possible C6 weakness can affect:
- Bending the elbow
- Turning the palm upward
- Extending the wrist backward
- Helping stabilize and rotate the shoulder
- Holding or carrying objects with the elbow bent
The biceps, brachioradialis, wrist extensors, and portions of certain shoulder muscles may show weakness.
This pattern could help explain why carrying my baby with my left arm becomes difficult so quickly. Holding a child requires continuous work from the shoulder stabilizers and elbow flexors rather than one brief burst of strength.
Within roughly five minutes, my pain can become miserable through the left side of my neck, shoulder blade, shoulder, and arm.
That does not prove C6 radiculopathy is the only cause, but it gives my doctors a real activity to consider when evaluating the weakness.
What Numbness Can C6 Radiculopathy Cause?
The classic C6 sensory pattern includes the outer forearm, thumb, and sometimes the index finger.
A person may experience:
- Numbness
- Tingling
- Pins and needles
- Burning
- Reduced sensitivity
- Unusual hot or cold sensations
Some people have substantial C6 weakness without much numbness. Others mainly experience pain and tingling.
The absence of thumb numbness does not automatically rule out a C6 nerve-root problem.
What Reflex Can Change With C6 Radiculopathy?
C6 radiculopathy may reduce the biceps or brachioradialis reflex.
The doctor may strike a tendon with a reflex hammer and compare the response on both sides.
A difference can support the suspected level when it matches the strength, sensation, imaging, and EMG findings.
Again, overlap matters. The biceps reflex is not controlled by only one completely isolated nerve root.
Why C5 and C6 Symptoms Overlap So Much
The body is not wired like a row of completely separate extension cords.
A muscle often receives nerve input from more than one cervical root. An area of skin may also receive overlapping sensory input.
For example, a muscle may receive substantial input from both C5 and C6. An injury affecting either root could therefore weaken the same general movement.
The pain itself can be even less predictable. Pain may spread into areas that do not match the classic dermatome diagrams shown online.
The AAPM&R review of cervical radiculopathy notes that expected pain-referral patterns may occur in only around 54 percent of patients in some studies.
That means nearly half of patients in those studies did not follow the clean textbook pattern.
Why Shoulder Pain Alone Cannot Tell C5 From C6
Both C5 and C6 problems can affect muscles involved in shoulder movement.
A person may feel pain in the shoulder even though the shoulder joint, tendons, and rotator cuff appear healthy.
I had my shoulder evaluated, and the shoulder doctor did not find a major structural problem that explained everything. I also experience popping with certain arm movements, which makes the shoulder feel involved even though the broader pattern continues pointing my doctors toward my neck.
Several conditions can resemble one another:
- C5 radiculopathy
- C6 radiculopathy
- Rotator-cuff problems
- Shoulder impingement
- Biceps tendon irritation
- Suprascapular nerve injury
- Axillary nerve injury
- Brachial plexus problems
- Muscle strain around the shoulder blade
- More than one condition occurring together
That is why a shoulder examination, cervical examination, imaging, and EMG may all be needed.
Can C5 or C6 Cause Shoulder-Blade Pain?
Yes. Both can potentially be associated with pain around the shoulder blade, although shoulder-blade pain is not exclusive to either nerve root.
C5 radiculopathy is often associated with pain near the medial border of the shoulder blade and outer upper arm. Cervical radiculopathy at other levels can also produce scapular pain. The relationship between these symptoms and C5-C6 nerve irritation is discussed in C5 radiculopathy and shoulder-blade pain.
Shoulder-blade pain may occur before the arm symptoms, alongside them, or without a strong hand pattern.
This is important in my case because the pain beside and underneath my left shoulder blade can feel like the center of the entire problem.
I previously explained how my neck and shoulder pain worsens when I let my arm hang normally. Supporting or lifting the arm can change the tension and reduce some of the discomfort.
That positional response may provide a clue, but it still cannot identify C5 or C6 by itself.
Can C5 or C6 Cause Upper-Back Pain?
Cervical radiculopathy can contribute to pain felt in the upper-back and shoulder-blade region.
This does not mean a cervical nerve runs as one simple cord down the back and arm. The nerve roots contribute to branching nerve networks that serve muscles and skin throughout the shoulder and upper limb.
Pain may also cause nearby muscles to tighten and compensate. The trapezius, rhomboids, rotator-cuff muscles, and other shoulder stabilizers may become painful when I change how I carry or support the arm.
I may therefore experience nerve-root pain and secondary muscle pain at the same time.
That mixed pain could help explain why ibuprofen reduces my overall nerve-related pain better than several nerve-pain medications I have tried.
Which Nerve Makes the Arm Tire Quickly?
Either C5 or C6 dysfunction could contribute to rapid arm fatigue, depending on the muscles involved.
C5 weakness may make it harder to hold the arm up at the shoulder. C6 weakness may affect elbow bending, wrist positioning, and shoulder stabilization.
Holding a child requires several movements at once:
- The shoulder must remain stable.
- The upper arm must stay positioned against the body.
- The elbow must remain bent.
- The forearm and wrist must support the weight.
- Shoulder-blade muscles must stabilize the entire structure.
Weakness anywhere in that chain can make the arm tire faster. Pain can also make the muscles shut down or compensate before they reach their true strength limit.
My next symptom article will look more closely at why the arm can become exhausted so quickly with cervical radiculopathy.
How an EMG Helps Separate C5 From C6
An EMG does not simply measure the most painful spot.
The doctor inserts small needle electrodes into several muscles. The goal is to identify a pattern across muscles supplied by different peripheral nerves.
For suspected C5 involvement, the doctor may examine muscles such as the deltoid, supraspinatus, infraspinatus, or other muscles receiving strong C5 input.
For suspected C6 involvement, the doctor may examine the biceps, brachioradialis, wrist extensors, and other appropriate muscles.
If abnormal muscles share the same cervical nerve root but receive their signals through different peripheral nerves, the findings may support radiculopathy.
My third test included electrical shocks followed by many small needle pokes in my hand, arm, areas closer to my neck, and a spot around my upper back. My recent article about what three EMG tests actually felt like explains the physical experience.
The latest doctor said the findings still appeared connected to C5-C6. I now want to know whether the written report specifically identifies C5, C6, or an overlapping C5-C6 pattern.
Can an EMG Be Certain About the Exact Nerve Root?
Not always.
An EMG may provide strong evidence of a cervical radiculopathy, but distinguishing one exact root can be difficult because muscles receive overlapping nerve input.
The doctor also has to select the correct muscles. An incomplete test may not provide enough information to separate C5 from C6.
The timing and severity of the injury matter as well. A mild or mainly sensory radiculopathy may produce a normal EMG even when the person has real pain.
This is why the report may use cautious wording such as:
- Findings consistent with C5 radiculopathy
- Findings consistent with C6 radiculopathy
- Chronic C5-C6 radiculopathy
- Active and chronic cervical radiculopathy
- Findings suggestive of a cervical nerve-root lesion
Those phrases are not interchangeable. I want the doctor to explain the exact wording used in my report.
Why My MRI and Symptoms May Not Match Perfectly
An MRI can show disc material, bone spurs, narrowing around a nerve root, the spinal cord, and other structures.
However, the most dramatic-looking level does not always cause the most severe symptoms. Some people have narrowing without pain, while others have significant symptoms without a dramatic MRI finding.
My artificial disc reportedly looks good after surgery. That is reassuring, but it does not completely explain why I continue experiencing weakness and pain.
I have already written about why an MRI can show little while the pain remains very real.
The MRI, EMG, physical examination, and symptom pattern each provide different information. The most useful diagnosis is the one that makes those pieces fit together.
What Symptoms Fit My Experience Most Closely?
My symptoms include substantial pain around the left side of my neck, shoulder blade, upper back, shoulder, and arm.
I also experience left-arm weakness and rapid fatigue while holding weight.
Some parts resemble a C5 pattern because the shoulder and shoulder-blade region are heavily involved. Other parts may fit C6 because my surgery was performed at C5-C6 and activities requiring elbow and shoulder support quickly become difficult.
That does not allow me to diagnose myself with one exact radiculopathy.
My third EMG gives the doctor more objective information, but I still need a detailed explanation of:
- Which muscles were abnormal
- Whether those muscles share C5 or C6 input
- Whether the changes appear active or chronic
- Whether the newest test improved or worsened compared with the earlier EMGs
- Whether another nerve or shoulder-blade problem could coexist
The article about whether a damaged cervical nerve can still heal after surgery explains why comparing all three EMGs matters at this stage.
Questions to Ask When a Doctor Says C5-C6
Do you mean the C5-C6 disc level or the C6 nerve root?
Those phrases are related, but they do not mean exactly the same thing.
Which muscles were weak during my examination?
The weak movement may help identify the affected root more accurately than the pain location alone.
Which muscles were abnormal on the EMG?
I want the doctor to connect each abnormal muscle to the suspected cervical root.
Did my reflexes differ between sides?
Changes in the biceps or brachioradialis reflex may support the rest of the findings.
Does my numbness follow a C5 or C6 pattern?
Outer upper-arm sensory changes fit C5 more closely, while thumb and index-finger symptoms fit the classic C6 pattern.
Could my shoulder still contribute to the symptoms?
Cervical radiculopathy and a shoulder condition can occur at the same time.
Is there evidence of active nerve injury?
Active denervation may mean something different from stable chronic changes remaining after an older injury.
Does the artificial disc still leave enough room for the nerve?
Good implant positioning is reassuring, but I want to understand the condition of the nerve opening and surrounding tissues.
Symptoms That Need Prompt Medical Attention
Ordinary cervical radiculopathy can be painful, but some neurological changes deserve faster evaluation.
I would contact a medical professional promptly for:
- Rapidly worsening arm or hand weakness
- New trouble holding or controlling objects
- Weakness spreading to other limbs
- New balance or walking problems
- Loss of hand coordination
- Severe symptoms after a new neck injury
- New bowel or bladder problems
- Fever with worsening neck pain
Symptoms involving balance, walking, both hands, or several limbs may raise concern about the spinal cord rather than only one nerve root.
The Main Difference I Finally Understand
C5 and C6 radiculopathy are not identified by pain location alone.
C5 generally stays closer to the shoulder and outer upper arm. It may weaken the muscles that raise and rotate the arm.
C6 more often travels down the outer forearm toward the thumb and index finger. It may weaken the biceps, brachioradialis, and wrist-extending muscles.
The patterns overlap, and many people do not match the textbook exactly.
In my case, the C5-C6 name may refer to the disc level where I had surgery, while the C6 nerve root may be the structure commonly affected at that level. My EMG doctor may also be describing an overlapping pattern rather than one completely isolated nerve.
The next thing I need is not another general statement that my EMG “still shows C5-C6.” I need the doctor to explain which muscles were abnormal, which root those muscles share, and whether the findings look active, chronic, or improving.
That information will help me understand whether the pain and weakness I still have 15 months after disc replacement fit C5, C6, or a more complicated combination.
Written by Daxon Weaver, who shares his real experiences with cervical disc replacement, lumbar fusion, chronic nerve pain, EMG testing, and spine surgery recovery on Spine Recover. This article describes one patient’s experience and is not a substitute for individualized medical care.
