Question 1: The "Head Turn" Trigger
Does your dizziness get worse when you turn your head quickly, look up, or tilt down at your phone?
Cervicogenic dizziness is specifically provoked by neck movements.
As Singapore’s leading Structural Correction expert, I resolve Cervicogenic Dizziness, chronic unsteadiness, and the "off-balance" feeling at the source. We fix the "glitchy" signals in your upper cervical spine with precise, X-ray-guided correction. Drug-free. Safe. Measurable.
The Structural Distinction
You cannot "strengthen" a bone back into its correct alignment. While general physiotherapy addresses the muscles, 2025 research confirms that Structural Correction of the cervical lordosis (the neck curve) provides a more definitive long-term resolution for balance disorders.
By restoring the curve first, we physically decompress the C1-C2 sensors, allowing your nervous system to naturally recalibrate your balance.
Doctor's Note
"In 20 years of treating neck patients in Singapore, I've seen hundreds of professionals who spent $3,000–$5,000 on MRIs, ENT visits, and neurologist consultations only to be told 'everythinglooks normal.'
The reason? Standard hospital imaging isdone lying down, which removes gravity andhides the structural shifts that cause your dizziness.
The answer was never in your ears or your brain. It was in your upper cervical spine all along."
Specifically, the C1 and C2 vertebrae - your body's primary 'GPS sensors' - were sending conflicting movement data to your brain the entire time.”

Understanding Your Dizziness
The unsettling "floaty" feeling when you stand up from your desk.
The world that seems to "lag" when you turn your head.
The vague heaviness behind your eyes that becomes a throbbing headache by 3 PM.
You've had the MRI. You've seen the ENT. Your hearing is "normal." Your brain scan is "clear."
Yet you still feel like you're walking on a boat.
Many of our patients describe it as a nightmare they cannot explain to anyone. You question your own sanity. You’re scared it’s something sinister, a tumour, MS, a stroke. Doctors say “it’s just stress” and hand you a prescription for Stemetil or Betaserc.
But the dizziness returns.
The headache returns.
And the fear never leaves.
The Daily Struggle
Your World is Shifting, But No One Else Can See It
You don't have the classic "room spinning" vertigo, but what you have is just as debilitating. It is a constant, vague sense of unsteadiness. Many of our patients describe it as feeling like they are "walking on a boat" or moving through thick water. Clinically, this is known as postural instability, a condition where your brain loses the ability to keep your body properly aligned over its center of gravity because the spatial data coming from your neck is completely corrupted.
The Singapore Reality:
The "Supermarket Effect"
Walking down the bright, busy aisles of NTUC or through crowded malls like VivoCity makes you feel completely overwhelmed and "floaty."
The "Traffic Tilt"
A split-second of panic when you turn your head quickly to check your blind spot while driving.
The "MRT Sway"
You feel unsteady standing on the train platform, even when you aren't moving.
The “Swimmy” Screen Switch
You feel uncoordinated and dizzy switching between dual monitors at your CBD desk, like your eyes can’t keep up with your head.
The Morning Stiffness Cascade
Waking with a stiff, heavy neck that escalates into a throbbing headache wrapping from the base of your skull to behind your eyes by lunchtime.
The Social Shutdown
Cancelling dinners, avoiding weekend sports, and declining travel because you never know when the next episode will strike.
The Anxiety Loop
The dizziness triggers anxiety, the anxiety tightens your neck muscles, the tighter muscles worsen the dizziness, a vicious, self-reinforcing cycle.
The "MBFC Elevator Drop"
Feeling the floor "sink" or your head "swim" when exiting the high-speed lifts at MBFC, Asia Square, or CapitaSpring.
The "Jewel Changi Overload"
Feeling disoriented or "floaty" while watching the movement of the Rain Vortex or navigating the busy glass walkways of Jewel.
Why Traditional Methods Fail?
Why Traditional Methods Fail?
You've tried the standard medical route: Stemetil, Betahistine, or resting. These might temporarily dull your brain's perception of dizziness, but the moment the medication wears off, the swaying returns. If the structural mechanical stress in your neck remains, the "signal jammer" is still active.
Deep Dive: The "Tech Neck" Connection
This sensory mismatch is often the neurological result of long-term Forward Head Posture (Tech Neck).
For a detailed look at how modern desk habits physically reshape your neck and "jam" your balance signals, visit our Structural Posture & Tech Neck Guide.
💡 Specialist Resource:
Does your "giddiness" peak after 4 hours at your desk? Learn how we reverse the structural damage of the Singapore CBD "Desk Hunch" here.

The Structural Toll of the CBD Desk Hunch. This X-ray shows a complete reversal of the natural curve (Cervical Kyphosis). In this position, the head exerts up to 3x its normal weight on the C1-C2 balance sensors, physically "jamming" the signals to your brain.
The "Fuse Box" Connection
The “Proprioceptive GPS”. Why Your Neck Controls Your Balance
Your body maintains balance through three integrated systems: your inner ear (vestibular system), your eyes (visual system), and the position sensors in your neck (proprioceptive system). What most people, and many doctors, don’t realise is that the upper cervical spine plays a disproportionately large role in this equation.
The C1–C2 “Fuse Box” - Your Body’s Most Sensitive Sensor Hub:
The suboccipital muscles surrounding C1 (Atlas) and C2 (Axis) contain the highest density of muscle spindles, specialised cervical mechanoreceptors, of any muscle group in the human body. Histological data confirms these deep neck tissues house up to 36 spindles per gram. These aren’t ordinary muscles; they are high-speed communication devices that tell your brain, every millisecond, exactly where your head is in space.
The Four Mechanisms of Sensory Disruption

Proprioceptive Convergence
Signals from these cervical sensors converge with vestibular and visual inputs at the vestibular nuclei, thalamus, and cerebral cortex, creating your “postural control system.” (Frontiers in Neurology, 2025).
.avif)
The Sensory Mismatch
When C1–C2 misalignment “locks” these joints, the sensors send distorted, frantic signals. Your eyes say you’re still, but your neck says you’re moving. The result? Your brain receives a data conflict it cannot resolve, and you experience dizziness, unsteadiness, or that vague “floating” sensation.
.avif)
Visual Dependence
Research confirms that patients with cervicogenic dizziness show increased visual dependence and impaired cervical relocation, meaning your brain gives up on neck data and over-relies on your eyes, making you vulnerable in visually complex environments like crowded MRTs and busy CBD streets. (De Hertogh et al., Frontiers in Neurology, 2025)
.avif)
The 50% Rotation Rule
Approximately 50% of all cervical spine rotation occurs at the C1–C2 joint. If this joint is restricted, every head turn generates corrupted position data, explaining why quick movements trigger your dizziness.
CLINICAL NOTE
While your primary symptom is dizziness, structural misalignments often present with secondary issues. If you are also experiencing Hand Numbness or Nerve Compression or have been diagnosed with Cervical Spondylosis (Neck Arthritis), please mention this during your initial assessment.
The Headache Connection
Why Dizziness and Headaches Often Travel Together
If your "off-balance" feeling is accompanied by a heavy, throbbing head, you aren't dealing with two separate problems. You are dealing with a single structural "short circuit" at the C1–C3 Neurological Crossroads.
The same nerve pathways that carry corrupted "GPS" data (causing your dizziness) converge at the brain’s headache relay station. This anatomical overlap is why a single structural correction often resolves both the "floaty" feeling and your chronic head pain simultaneously.
The "Ram’s Horn" Sign
If your pain wraps from the base of your skull to behind your eye, it is the #1 indicator that your dizziness is coming from your neck.
The Vagus Connection
Structural pressure here can also trigger the nausea and "heavy head" feeling that often mimics a migraine.
Are your headaches more debilitating than your dizziness?
Explore our dedicated Migraine & Headache Treatment page for a full clinical breakdown of the "Ram's Horn" pattern and how we decompress the Greater Occipital Nerve.
Self-Assessment
Before you scroll further, try this simple test:
Stand with your feet together on a flat surface.
Slowly turn your head to the far left, then to the far right.
Check for any visual lag, sway, or unsteadiness.
Do you feel a "lag" in your vision, a sudden sway, or a sense of unsteadiness? If your eyes struggle to "re-anchor" to the room when your neck moves, it is a classic indicator that your upper cervical proprioceptors are misaligned. This isn't an ear problem; it's a "signal lag" from your neck.

The "Self-Diagnosis" Tool
Most Singaporeans call it "giddiness," but identifying the exact type of dizziness is the first step to fixing it. True spinning vertigo is often an inner ear (BPPV) issue, while an "off-balance" or "floaty" feeling is typically Cervicogenic Dizziness, caused by a structural misalignment in your neck.
Take our free, 60-second assessment below to decode your symptoms, or scroll down to read the full clinical checklist.
The 7 Clinical Signs of Cervicogenic Dizziness
The “Head Turn” Trigger
Dizziness provoked specifically by neck movements or looking up.
The “Stiffness Precursor”
Neck pain that appears before or alongside the dizziness.
The “Normal Test” Paradox
Your ENT and MRI tests are clear, but the "floaty" feeling persists in the CBD office.
The “Not Spinning” Distinction
Feeling unsteady or heavy-headed rather than experiencing room-spinning vertigo.
The “Ram's Horn” Headache
Pain wrapping from the base of the skull to the eye.
The “Air-Con” Spike
Office AC drafts triggering hypersensitive cervical nerves.
The “3 PM Office” Peak
Symptoms worsen after hours at a desk and ease when lying down.
Also experiencing other "glitches"?
NOTE
Pain wrapping from the base of the skull to the eye - read our guide to resolving Tension Headaches & Migraines
NOTE
If you have a stiff neck but absolutely zero dizziness or neurological symptoms, please visit our Neck & Shoulder page instead.
CLINICAL REFERENCE - Key Discovery
A 2025 Frontiers in Neurology review confirms that the key diagnostic indicators for cervicogenic dizziness include: neck pain preceding dizziness, temporal relationship between dizziness and neck symptoms, and dizziness provoked by cervical movements. The presence of neck symptoms is a required diagnostic criterion.
Why Traditional Methods Fail
You've likely been through the standard Singapore medical route. Here's why that cycle fails:
MEDICATIONS
These drugs treat the wrong organ entirely.
Anti-vertigo medications like Stemetil (prochlorperazine) and Betaserc (betahistine) target the inner ear and vestibular system. If your dizziness is cervicogenic, these drugs are treating the wrong organ entirely. You might get temporary dulling of symptoms, but the structural misalignment that generates the corrupted signals remains untouched.
MRI GAP
Hospital MRIs eliminate gravity as a factor.
Hospital MRIs in Singapore are performed lying down, eliminating gravity as a factor. The very structural shifts causing your symptoms under the load of daily upright posture disappear when you’re horizontal. Our Weight-Bearing Structural Analysis identifies posture-dependent misalignments that standard imaging consistently misses.
PHYSIOTHERAPY
You're using muscle to fight a bone problem.
Standard physio focuses on strengthening muscles and general exercises. But if the underlying vertebral alignment is wrong, muscle strengthening cannot force a bone back into position. You’re using muscle to fight a bone problem, and patients consistently report that non-specific PT provides, at best, temporary relief.
ENT LIMITS
The cervical spine is rarely examined.
ENT specialists are trained to diagnose inner ear disorders, including BPPV, Meniere’s disease, and vestibular neuritis. When their tests come back “normal,” many patients are told “it’s just stress” or “anxiety.” The cervical spine is rarely examined. Yet a landmark scoping review of 156 studies published by Gill-Lussier et al. (2023) confirms that cervicogenic dizziness is a well-evidenced, clinically distinct, and treatable condition. Furthermore, 2025 research in Frontiers in Neurology highlights that it requires focused physical examination of the upper cervical spine and its links to oculomotor function, something standard ENT testing completely skips.
KEY FINDING
A 2024 study in JAMA Otolaryngology–Head & Neck Surgery demonstrated that patients with Cervical Spondylosis have an elevated risk of cervicogenic dizziness, confirming that the structural condition of the neck directly drives the dizziness.
Athletes & Active Professionals
Most clinics only treat seniors for balance issues. But for Singapore’s active community, like BJJ fighters, rugby players, and CrossFitters, sudden dizziness is rarely an ear issue. It is often a delayed neurological symptom of an old trauma.
The Whiplash Loop
A hard tackle or fall "jams" the upper neck joints.
Misaligning the Atlas (C1) by mere millimetres. Read more about the hidden damages of whiplash.
The Visual Lag
A split-second delay where your vision can't keep up.
You notice it during a heavy squat or a sprint, a split-second delay where your vision struggles to catch up to your body's movement. A heavy axial load can also cause a cervical disc herniation that compounds your balance issues.
The Performance Drop
Your brain spends 30% of its energy just keeping you upright.
We don't just patch the pain; we recalibrate the joint receptors so your athletic balance returns to 100%. (If your injury was recent, see our Neck Injury page).
Pro-Athlete Tip
If your "balance" feels off during high-intensity training, your C1 'GPS' is likely misaligned. Don't lose your competitive edge to a 'Signal Jam.'
The Solution
I understand the terror of living with unpredictable dizziness. The fear of driving, the anxiety at your desk, the dread of crowded spaces. I understand the frustration of being told “everything is normal” when you know something is deeply wrong.
After treating over 3,000 neck patients in Singapore, I’ve learned that lasting relief from cervicogenic dizziness and headaches only comes from correcting the structural misalignment that creates the proprioceptive “signal noise”.
At Dr Neck Pain Singapore, we don't just ask where it hurts. We use precision X-ray analysis to find exactly WHERE the misalignment is, HOW MUCH it has shifted, and WHAT nerve pathway it is disrupting. Then we correct it.
We don't suppress your symptoms with medication. We correct the structural misalignment that creates the proprioceptive "signal noise", eliminating the cause, not just dulling the effect.
BENEFITS

The dizziness stops because the cause no longer exists.
We identify and realign the exact vertebrae sending distorted proprioceptive signals. By restoring structural alignment, the sensory mismatch is physically eliminated, and the dizziness stops because the cause no longer exists.
.avif)
The anxiety naturally reduces because the trigger no longer exists.
Research confirms a vicious cycle: dizziness triggers anxiety, anxiety tightens neck muscles, tighter muscles worsen the proprioceptive disruption, causing more dizziness. Structural correction breaks the physical foundation of this loop. When the cervical structure is corrected, your nervous system stops generating the cascade, and the anxiety naturally reduces because the trigger no longer exists.
.avif)
The neurological and vascular trigger mechanism is structurally resolved.
By correcting the C1–C2 alignment, we decompress the Greater Occipital Nerve and restore proper blood flow through the vertebral arteries. The “Ram’s Horn” headache pattern, the “3 PM brain fog,” and the stabbing pain behind your eyes stop because the neurological and vascular trigger mechanism has been structurally resolved. A 2025 network meta-analysis confirmed that spinal manipulation of the upper cervical spine shows significant benefit for cervicogenic headache outcomes. (Xu & Ling, Frontiers in Neurology, 2025)
.avif)
You get your life back.
With the structural dysfunction corrected, you can turn your head without triggering an episode. You can drive without gripping the steering wheel in fear. You can walk through Orchard Road or the MRT without feeling like the floor is shifting. You get your life back.
THE Process
We use a precise, medical-grade methodology to physically realign your upper cervical spine and restore clear communication between your neck, eyes, and brain.
We trust that the ENT and/or Neurologist have performed a proper vestibular assessment. We use precise digital X-rays to look for the Atlas Misalignment, the exact millimetre of deviation at the top of your neck that is jamming your brain's GPS, and we link it with your cervical lordosis. We map your specific Cervico-Ocular Pathways so we never have to guess.
We use targeted techniques to calm the deep fascial adhesions and "protective guarding" in the suboccipital muscles (the muscles at the base of your skull that control your eye-tracking).
We apply a gentle, highly specific correction to the C1/C2 vertebrae and the lower neck to "reboot" the signal. Note: No aggressive "cracking" or heavy rotation is used for dizziness cases; we use exact, measured precision.
We provide highly specialised, customised vestibular rehabilitation exercises to retrain your eyes, inner ears, and neck joints to work together smoothly. While traditional, generalised vestibular rehabilitation therapy often fails because it ignores the underlying bone alignment, our protocol combines these advanced neurological balance exercises with physical structural correction.
Reclaim your steady footing with a head that feels "grounded." We finalise your 90-day protocol with post-correction X-rays to physically verify the improvement in your upper cervical alignment, ensuring the mechanical "signal jammer" is permanently resolved. This ensures the brain automatically maintains a clear, unjammed signal even in crowded, visually complex environments.
From Confusion to Clarity
From Confusion to Clarity
Most patients don’t arrive knowing they have Cervicogenic Dizziness. They arrive confused, frustrated, and scared. Here’s the journey we guide you through
Stage 1
“I have Vertigo (spinning)”
“Is the room spinning, or do YOU feel ‘off’? There is a massive difference. Spinning = inner ear. ‘Off-balance’ = likely your neck.”
Stage 2
“It’s an inner ear infection”
“If your ENT balance tests are clear, your ‘Upper Cervical GPS’ is likely sending corrupted data to your brain.”
Stage 3
“It’s just stress / CBD burnout”
“You aren’t burnt out. Your brain is over-processing conflicting spatial signals from a misaligned neck, and it’s exhausting your nervous system.”
Stage 4
“Could it be my neck?”
The Answer
“Yes. The C0–C2 connection: these 3 segments house the body’s highest density of balance sensors. Even 1mm of shift can cause 100% of your dizziness.”
TCM vs Structural Reality
Is it "Poor Circulation" or a Mechanical Blockage?
In Singapore, we often use TCM terms to describe dizzy spells. While the descriptions of the sensations are incredibly accurate, treating the sensation won't fix a locked structural joint.
You Feel
Lightheaded / Faint
TCM Term
"Poor Blood Qi"
Structural Reality
Vertebral Artery Compression: A misaligned, stiff neck can physically restrict optimal blood flow to the brain's balance centres.
You Feel
Heavy / Unsteady
TCM Term
"Internal Wind"
Structural Reality
Proprioceptive Noise: Your locked neck joints are "screaming" conflicting GPS coordinates at your brain, causing sensory overload.
You Feel
Nauseous / Giddy
TCM Term
"Heatiness"
Structural Reality
Vagus Nerve Irritation: The "locked" upper neck irritates the cranial nerves responsible for your stomach and spatial awareness.
Dizziness Decoder
In Singapore, we often use the catch-all term "giddy" whether the room is spinning violently or we just feel a bit faint. But medically, how you feel dizzy tells us exactly where the biological or structural failure is hiding.
Many of our patients waste thousands of dollars and months of their lives bouncing between ENTs and Cardiologists simply because they are treating a "neck problem" as an "ear problem." Use this quick diagnostic guide to decode your specific symptoms and ensure you are finally treating the true source.
Clinical Note on Red Flags
It is vital to differentiate true cervicogenic dizziness from rare, high-risk vascular conditions like vertebrobasilar insufficiency (a transient restriction of blood flow to the brainstem) or acute stroke.
Neck-Related Signal
A mechanical "signal lag" during head movement and walking.
TCM Term
Sudden slurred speech, double vision, or dropping to the floor.
If structural cervical dysfunction is your primary driver, correcting the C1–C2 alignment addresses the source - without high-risk, aggressive spinal twisting.
The Room is Spinning
Violent, rotational dizziness, especially when rolling over in bed.
LIKELY CAUSE
BPPV / Inner Ear
NEXT STEP
See an ENT Specialist.
Throbbing/Stabbing Pain
Intense pressure or a "Ram's Horn" pain wrapping around your eye.
LIKELY CAUSE
Migraine / Tension
NEXT STEP
Unsteadiness / "Floating"
Feeling like you are walking on a boat, or swaying when standing still.
LIKELY CAUSE
Cervicogenic Dizziness
NEXT STEP
Faint when Standing Up
A sudden "blackout" or lightheaded rush when getting out of a chair.
LIKELY CAUSE
Postural Hypotension
NEXT STEP
See a GP / Cardiologist.
My ENT at SGH or Mount Elizabeth says my ears are fine, but I’m still dizzy. What’s going on?
Is Cervicogenic Dizziness the same as Vertigo?
Can neck problems really cause dizziness?
How long do cervicogenic dizziness episodes typically last?
I’ve tried physiotherapy and sports massage before without lasting results. How is this different?
Can "Tech Neck" from my CBD office job cause both dizziness and headaches?
Why does my dizziness get worse on the MRT, escalators, or in shopping malls like Jewel Changi?
I have "Brain Fog" along with my dizziness. Is that normal?
Can Cervicogenic Dizziness cause anxiety or panic attacks?
How long does treatment take, and is it permanent?
Is this treatment covered by insurance in Singapore?
I also have tinnitus (ringing in my ears). Is that related to my neck?
You shouldn't have to "survive" your workday in the Singapore CBD by gripping your desk every time you stand up, or live in fear that the ground will "shift" while crossing a busy street. Whether you are terrified of collapsing in a crowded MRT station or are simply exhausted by constant brain fog, the problem isn't "just stress," anxiety, or an unresolvable inner ear infection. It is a mechanical misalignment in your upper cervical spine.
Our R3NEW X™ Program is a precise, non-surgical solution designed to realign your C1-C2 "Fuse Box," relieve proprioceptive signal noise, and permanently restore clear communication between your neck, eyes, and vestibular system.
Many patients come to our Singapore chiropractic clinic after spending thousands on medical tests that found "nothing." We operate differently by tracking objective, measurable milestones. Because clinical data demonstrates that resolving upper cervical structural distortion directly relieves the mechanical trigger for cervicogenic dizziness and cervical vertigo, we back our specialised care programs with a formal structural baseline commitment.

Our 90-Day "Balance Restoration" Guarantee
For patients who qualify and enroll in our comprehensive 90-Day Structural Guarantee Program, we establish strict, digital X-ray-verified targets at day one. If we do not successfully achieve objective improvement in your cervical lordosis or upper cervical alignment on your post-care imaging, we will refund your entire treatment fee
We don't just promise the "floating" feeling will stop; we prove it with post-correction X-ray imaging.
T&C Applies.
Book your initial consultation, which includes a complete vestibular history, cervical neurological testing, and precise digital X-ray analysis to locate exactly where your balance signals are being disrupted.
We review your specialised cervical spine X-rays together to definitively show how your C1 or C2 vertebrae have shifted, and to map out your 90-day structural correction and recovery plan.
Start your targeted R3NEW X™ journey and experience the relief of a head that feels clear, steady, and fully "grounded" again right here in Downtown Singapore.
Conveniently located at North Bridge Centre, our clinic is the preferred choice for office workers and executives in Bugis, City Hall, and the Singapore CBD. Whether you are battling a "floating" sensation at your desk in Marina Bay or struggling with unsteadiness on your MRT commute, we are easily accessible for precise structural correction.
We understand the specific demands of the local corporate lifestyle, the 12-hour "Desk Hunch," the high-stress environment of the CBD, and the ergonomic strain of dual-monitor setups that jam your upper cervical spine. That is why our appointment slots and R3NEW X™ program are designed for maximum efficiency, allowing you to fit specialised balance care into your lunch break without disrupting your workflow.
The Structural Approach
We don't just prescribe motion sickness pills to dull your senses; we fix the mechanical "signal jammer" at the base of your skull. Our method restores the alignment of your C1 and C2 vertebrae, permanently clearing the proprioceptive noise.
Specialist Diagnosis
We find the subtle cervical misalignments causing your "giddiness" that standard hospital MRIs (done lying down) and ENT tests completely miss.
No "Package Traps"
Results-focused care. We aim to recalibrate your internal GPS and decompress your nerves so you can get back on solid ground, permanently.
Private & Professional
A focused, calm clinical environment designed for high-performing professionals who may be experiencing sensory overload or anxiety during dizzy spells.
Find Us in the Heart of Singapore
📍 Clinic Address: 420 North Bridge Rd, #02-20 North Bridge Centre, Singapore 188727
🚇 MRT: 5-minute walk from Bugis MRT (East-West & Downtown Lines) or City Hall MRT Station
🅿️ Parking: Available at National Library of Singapore, Bugis Junction, and InterContinental Singapore
We are the trusted structural correction specialists for residents across the island:
Centre
Orchard, River Valley, Tanglin, and Newton.
Business Hubs
Tanjong Pagar, Raffles Place, Marina Bay,and Suntec City.
Heartlands
We frequently welcome patients from Tampines, Jurong, and Bishan who have "tried everything" and are seeking specialised Cervicogenic Dizziness and balance care not found in general GP or ENT clinics.
Every recommendation at Dr Neck Pain Singapore is grounded in peer-reviewed research. Below are 10 published studies from Frontiers in Neurology, JAMA, BMC and leading medical journals, documenting why your dizziness is coming from your neck, how the top two vertebrae control your balance, why ENT scans come back clear, and why structural correction works where medication fails.
Clinical References & Medical Sources
10 peer-reviewed studies: proprioception, manual therapy, postural control, prevalence, spondylosis risk & upper cervical dysfunction