Plausible impact of forward head posture on upper cervical spine stability

Abstract

The cervical spine is responsible for allowing mobility and stability to the head and neck. Any deviation to the center of gravity of the head results in an increase in cantilever loads, which can be particularly damaging to the upper cervical joints. Excessive neck bending also exaggerates stretching through the cervical spine and all of the spinal structures below. It has been reported that forward head posture (FHP) can cause a multitude of disorders including cervical radiculopathy, cervicogenic headaches and cervicogenic dizziness. Most of these conditions manifest with clusters of painful symptoms and spine dysfunctions. The purpose of this case study is to describe the radiographic imaging considerations and to illustrate the potential impacts in symptomatic adults with FHP. We randomly selected radiographs of three individuals with FHP who had undergone cervical adjustment for cervical pain. The occipito‐axial (C0‐C2) and atlanto‐axial (C1‐C2) joints were assessed via the C0‐2 distance from the C2 base to the McGregor line (Redlund‐Johnell criterion) and the Ranawat C1‐2 index, in addition to subjective radiographic parameters. By comparing the radiographs of before‐and‐after intervention of each patient, a regressive joint spacing was observed from both indices. Such a long‐lasting stretching concordant with FHP was assumed to be hazardous to joint stability. A definite conclusion, however, cannot be drawn due to the small sample size and a lack of convincing measurements.

Full text

© 2020 Journal of Family Medicine and Primary Care | Published by Wolters Kluwer - Medknow 2517
Introduction
Ithasbeenreportedthatforwardheadposture(FHP)cancause
a multitude of disorders including cervical radiculopathy,[1]
cervicogenic headaches,[2] and cervicogenic dizziness.[3] The
purpose of this report is to shed light on the potential impacts
of  FHP on upper cervical stability in symptomatic adults.
Radiographic parameters used in this report included the
following: The center of gravity of the head was approximated
by using the anterior portion of the external auditory canal as
the initial point for the plumb line,[4] cervical gravity line is a
plumb line drawn through the apex of the dens. Both gravity
lines allow a gross assessment of the gravitational stresses.
McGregor’slineisthelinedrawnbetweenthehardpalateand
the most caudal occipital point, and is used to assess a vertical
displacement of the C2 relative to insert proper parameter.
Redlund‑Johnell criterion is the distance from the base of C2
totheMcGregor’sline(males>34mmandfemales>29mm).
Ranawat’s line is the perpendicular distance between the midpoint
of the base of C2 and a line drawn along the axis of the C1
vertebra,(males>23.7 mm, females>24.2mm).[5] Swischuk’s
line is the line drawn between the laminae of C1 and C3 on a
lateralX‑ray.C2shouldbewithin1.5–2mmof thisline.There
are several radiographic parameters commonly used to assess
the cervical alignment including lordotic angle, cranio‑vertebral
angle, neck tilt, etc., However, a gross angle measurement may
be obliterated by the effect of segmental deformities, as those
Plausible impact of forward head posture on upper
cervical spine stability
Eric C. P. Chu1, Fa Sain Lo1, Amiya Bhaumik2
1New York Chiropractic and Physiotherapy Centre, New York Medical Group, Hong Kong, China, 2Faculty of Sciences, Lincoln
University College, Kelantan, Malaysia
Abs tr Ac t
The cervical spine is responsible for allowing mobility and stability to the head and neck. Any deviation to the center of gravity of
the head results in an increase in cantilever loads, which can be particularly damaging to the upper cervical joints. Excessive neck
bending also exaggerates stretching through the cervical spine and all of the spinal structures below. It has been reported that forward
head posture (FHP) can cause a multitude of disorders including cervical radiculopathy, cervicogenic headaches and cervicogenic
dizziness. Most of these conditions manifest with clusters of painful symptoms and spine dysfunctions. The purpose of this case
study is to describe the radiographic imaging considerations and to illustrate the potential impacts in symptomatic adults with
FHP. We randomly selected radiographs of three individuals with FHP who had undergone cervical adjustment for cervical pain.
The occipito‑axial (C0‑C2) and atlanto‑axial (C1‑C2) joints were assessed via the C0‑2 distance from the C2 base to the McGregor
line (Redlund‑Johnell criterion) and the Ranawat C1‑2 index, in addition to subjective radiographic parameters. By comparing the
radiographs of before‑and‑after intervention of each patient, a regressive joint spacing was observed from both indices. Such a
long‑lasting stretching concordant with FHP was assumed to be hazardous to joint stability. A definite conclusion, however, cannot
be drawn due to the small sample size and a lack of convincing measurements.
Keywords: Atlantoaxial joint, cervical adjustment, forward head posture, instability, occipito‑axial joint
Case Report
Access this article online
Quick Response Code:
Website:
www.jfmpc.com
DOI:
10.4103/jfmpc.jfmpc_95_20
Address for correspondence: Dr. Eric C. P. Chu,
New York Chiropractic and Physiotherapy Centre, 41/F Langham
Place Office Tower, 8 Argyle Street, Hong Kong, China.
E‑mail: eric@nymg.com.hk
How to cite this article: Chu EC, Lo FS, Bhaumik A. Plausible impact
of forward head posture on upper cervical spine stability. J Family Med
Prim Care 2020;9:2517-20.
This is an open access journal, and articles are distributed under the terms of the Creative
Commons Attribution‑NonCommercial‑ShareAlike 4.0 License, which allows others to
remix, tweak, and build upon the work non‑commercially, as long as appropriate credit is
given and the new creations are licensed under the identical terms.
For reprints contact: WKHLRPMedknow_reprints@wolterskluwer.com
Received: 16‑01‑2020 Revised: 12‑03‑2020
Accepted: 15‑03‑2020 Published: 31‑05‑2020

Chu, et al.: Cervical instability in forward head posture
Journal of Family Medicine and Primary Care 2518 Volume 9 : Issue 5 : May 2020
with the S‑shaped cervical curvature [Figure 1a]. The regional
vertebral anomaly must be taken into consideration when dealing
with a gross curve assessment.
Case Reports
This retrospective chart review was exempted from the ethics
committee/IRB approval.
Case 1
A55‑year‑oldmale, ofceworker,presentedwith ahistoryof 
progressively worsening nuchal pain and paresthesias radiating
into the right shoulder and arm of 6 months duration. The
symptoms were worse in the latter part of the day. On clinical
examination,thepatientexhibitedforwardheadposture(FHP),
joint restrictions in upper and mid cervical regions, limited
cervical extension, and sensory deficit consistent with C5
dermatomal distribution. The cervical radiography [Figure 1a]
showed a loss of cervical lordosis, backward subluxation of
the C4 on C5 (red circle), and an occipital enthesophyte (white
arrow). A right C5 radiculopathy was diagnosed, and subsequently
cervical adjustment was commenced. After 12 sessions of
chiropractic treatment, the patient experienced complete
alleviation from nuchal pain and radicular symptoms. At 9 month
follow‑up radiographs revealed a restoration of the cervical
curvature [Figure 1b].
Case 2
A 49‑year‑old female, accounting manager, presented with neck
pain and radicular pain travelling down the right shoulder and
back of the arm and forearm, going into the 4th and 5th digits.
The symptoms were sometimes exacerbated after working on a
computer for long periods. Her primary care physician suggested
that she was suffering from a spinal degeneration and cervical
radiculopathy. The patient underwent physiotherapy and was
prescribed pain medications and herbal remedies over 9 months
duration with only minimal relief. Upon presentation to
our clinic, the patient exhibited FHP. The cervical range of 
motion(ROM)waslimitedto50°rightrotation(normal>90°)
and30°extension(normal>70°).Theintersegmentalrestrictions
were found at C4/5, C5/6, and C7/T1 levels. The cervical
radiography [Figure 2a] displayed reverse cervical lordosis and
degenerative spondylosis with ankylosis of the C7/T1 facet
joints (red circle). In addition, some rotatory displacement of
the C2 was suspected on open mouth view [Figure 3a]. The
patient underwent chiropractic treatment consisting of thermal
ultrasound therapy, spinal mobilization, cervical adjustment, and
cervical extension‑compression traction. The symptoms started
to get better and were resolved at 2 months. The X‑ray indicated
a satisfactory restoration of the cervical lordosis at 9 months
follow‑up [Figure 2b].
Case 3
A 43‑year‑old female, tness trainer,complained of  chronic
nuchal pain and bilateral upper arm pain. Her symptoms
began 2 years prior and had intermittent, insidious symptom
exacerbation. She described the pain as starting from her neck
and extending down to her right shoulder and then to the lateral
forearm. In the absence of  identiable pathology on cer vical
magnetic resonance imaging (MRI), she initiated non steroidal
anti‑inammatorydrugs(NSAID)treatmentanddidnotattain
anysignicantimprovement.Theregularmassagetherapyoffered
some temporary symptomatic relief but no long lasting results.
Approximately one week prior to presenting to our clinic, the
patient had experienced severe, acuteare‑up of  the nuchal
symptoms with shoulder numbness. She sought chiropractic
Figure 2: Cervical spine lateral view of Case 2. (a) Prior to treatment
lateral radiograph displayed a reverse cervical lordosis, degenerative
spondylosis with ankylosis of the C7/T1 facet joints (red circle). The
cervical gravity line (blue dotted line) just touched the anterior body
of the C7. (b) The repeat lateral radiographs 9 months later exhibited
improved general cervical lordosis. A smooth vertical alignment of each
posterior body corner was noted. The cervical gravity line fell within the
C7 vertebra. Redlund‑Johnell criterion (white dotted line) was reduced
by 6.55% and Ranawat index (red dotted line) was reduced by 8.88%
b
a
Figure 1: X‑ray comparison of pre‑ and post‑intervention in
Case 1. (a) The initial X‑ray displayed a loss of cervical lordosis,
backward subluxation of the C4 on C5 (red circle), and an occipital
enthesophyte (white arrow). The cervical gravity line (blue dotted line)
fell forward of the C7 suggestive of anterior head placement. (b) The
9 months follow‑up X‑ray showed the correction of both the neck curve
and the forward head posture. The cervical gravity line fell within the C7
vertebra. Redlund‑Johnell criterion (white dotted line) was reduced by
11.11% and Ranawat index (red dotted line) was reduced by 13.72%
b
a

Chu, et al.: Cervical instability in forward head posture
Journal of Family Medicine and Primary Care 2519 Volume 9 : Issue 5 : May 2020
care and rated the pain at 4/10 on a numeric pain score. The
cervicalROMwaslimitedto70°bilateralrotation(normal>90°)
and40°extension(normal>70°).Thespinalpalpationrevealed
intersegmental restriction at the cervicothoracic junction. The
cervical radiography [Figure 4a] revealed a loss of cervical
lordosis, narrowing of the C7/T1 interspace, and facetitis of
the right C5/C6 and C7/T1 facet joints. In addition, some
rotatory displacement of the C2 was suspected on open mouth
view [Figure 3b]. She was diagnosed with degenerative spondylosis
with possible right C6 radiculopathy. The treatment included
thermal ultrasound, cervical extension‑compression traction, and
spinal manipulation. Within 3 months of initiating the treatment,
thepatient hadsignicant improvementof  hersymptoms and
continued to receive maintenance chiropractic treatment. The
radiographs obtained 2 years since the beginning of treatment
revealed complete restoration of the cervical curve [Figure 4b].
Discussion
The upper cervical spine (C0‑C2) is responsible for 50% of
total neck exion and extensionas as well as 50% of  overall
cervicalrotation.TheFHPinvolvesincreasedextensionsof the
upper cervical vertebrae, extension of the occiput on C1, and
increasedexionof thelowercervicalvertebraeandtheupper
thoracic regions. While the ligaments act as sensory organs
involvedinligamento‑muscularreexes,jointdisplacement(s)
producepainandmusclespasms.Thereexisemanatedfrom
the ligamentous mechanoreceptors (i.e. pacinian corpuscles,
golgi tendon organs, and rufni endings) and transmitted to
the muscles.[6] In the upper cervical spine, joint instability can
cause a number of biomechanical symptoms including, but not
limitedto,vertebrobasilarinsufciency,cervicogenicdizziness,
head and facial pain, nerve irritation, and cervical radiculopathy.[6]
Therefore,itisreasonabletoassumethatinsomecasesof FHP,
the root cause of complaints may be underlying biomechanical
effects due to joint instability.
A bony spur (enthesophyte) projecting from the external
occipital protuberance [Figure 1a] is a vestigial trait as evidence
for previous enthesitis (insertional tendinitis). The enthesis is
the insertional site of where a tendon or ligament attaches to
the bone. Repetitive biomechanical strain and micro damage
caninducecytokinestotriggeraninammatoryresponseinthe
adjacent synovial tissue leading to synovitis.[7] Substantial immune
responsecontributesto abnormalinductionof brous tissue/
bro cartilage‑bone interactions resulting in radiographically
detectable enthesopathy (insertional tendinopathy).[7,8] In cases of
FHP,longlastingpullonthenuchalligamentandnuchalmuscle
created by abnormal postures can cause insertional tendinitis
and bony spur in the nuchal ligament, which extends from the
external occipital protuberance to the spinous process of the
7th cervical vertebra.
The scientic literature indicates that posture, radiographic
positioning, and radiographic line drawing are all very reliable/
repeatable.[9] There are some limitations for the measurement
of  distance and cervical angle. Firstly,most radiog raphic
lms were obtained retrospectively from clinicians’ referral.
There were technical problems to measure the length of line
segments from hard‑copy lms. Secondly, the patients were
positioned to be routinely desired while taking radiography.
The lordosis angle measurement may be independent of a
resting posture. In addition to the effect of segmental spine
deformity,justmeasuringC2‑C7lordosisangledidnotreecta
gross curvature. The S‑shaped cervical spine may obliterate the
angle measurement by a compensatory backward tilting at the
lower neck [Figure 1a]. However, the afore mentioned biases
would be avoided because the radiographic parameters in this
report were analyzed by comparing the differences between the
before‑and‑after images. Both Redlund‑Johnell (white dotted
line) and Ranawat (red dotted line) indices regressed, with average
Figure 3: Open mouth radiographs of Case 2 (a) and of Case 3 (b)
at initial presentation. There was symmetrical spacing of lateral
zygapophyseal (C1‑C2) joints and of odontoid‑lateral mass intervals.
Note a deviation of the C2 spinous process with respect to the alignment
of the dens, a suggestive nding of C2 rotation
b
a
Figure 4: Initial and follow‑up radiographs of Case 3. (a) Initial radiograph
showed a loss of cervical lordosis, osteophytic lipping of the vertebrae,
narrowing of the joint space of the C7/T1, and facetitis of the right C5/C6
and C7/T1 facet joints. (b) The repeat radiography 2 years later exhibited
improved general cervical lordosis. There was a smooth vertical alignment
of each posterior vertebral corner. Redlund‑Johnell criterion (white dotted
line) was reduced by 6.34% and Ranawat index (red dotted line) was
reduced by 10.41% FHP (Forward head posture)
b
a

Chu, et al.: Cervical instability in forward head posture
Journal of Family Medicine and Primary Care 2520 Volume 9 : Issue 5 : May 2020
approximation of 8% and 11% respectively. The symptomatic
improvement is the supporting evidence for radiographic
changes. Any pre‑to‑post alignment changes in patients are a
result of the treatment procedures applied.[9]
The most common postural abnormality is the FHP arising
from modern lifestyle. An observational assessment by a
generalpractitionerwilldetectsignicantfaultsintheposture,
e.g. presence of head tilt, forward head posture, uneven shoulders,
spinal misalignment, and spinal curvature deformities. It will
give an overview of the patient’s problems in clinical settings.
Analysis of a patient’s posture offers information about the
muscle endurance and the muscle capability to cope with physical
stressors. Severalrepor ts haveestablished the FHP as a real
clinicalentitywithsignicantmusculoskeletalconsequences.[10]
TheFHPcangetworseovertime,causingspinaldegeneration,
muscle weakness and tightness, entrapment neuropathies, and
the loss of vital lung capacity. The general practitioner provides
immediatemedicalassistancefortheFHPpatientwithabroad
range of complains. The practitioner can become an effective
facilitator for alleviating pain and preventing damage where
abnormal posture is found to be a main contributing factor.
Conclusion
By comparing the radiographs before‑and‑after correction of
theFHPinthreesymptomaticpatients,aregressivejointspacing
was observed from both Redlund‑Johnell criterion ((C0‑C2))
and the Ranawat C1‑2 index. The radiographic parameters
illustrated the potential impacts on upper cervical stability in
symptomatic cases.
Declaration of patient consent
A copy of the written consent is available for review by the
Editor‑in Chief of this journal.
Financial support and sponsorship
Nil
Conflicts of interest
Theauthorshavenoconictsof interesttodeclare.
References
1. Chu RCP, Lim T, Mak KC. Cervical radiculopathy alleviating
by manipulative correction of cervical hypolordosis. J Med
Cases 2018;9:139‑41.
2. Chu ECP, Chu VKY, Lin AFC. Cervicogenic headache
alleviating by spinal adjustment in combination with
extension‑compression traction. Arch Clin Med Case Rep
2019;3:269‑73.
3. Chu RCP, Chin WL, Bhaumik A. Cervicogenic dizziness. Oxf
Med Case Reports 2019;11:476‑8.
4. Scheer JK, Tang JA, Smith JS, Acosta FL Jr, Protopsaltis TS,
Blondel B, et al. Cervical spine alignment, sagittal deformity,
and clinical implications: A review. J Neurosurg Spine
2013;19:141‑59.
5. Kwong Y, Rao N, Latief K. Craniometric measurements in
the assessment of craniovertebral settling: Are they still
relevant in the age of cross‑sectional imaging? AJR Am J
Roentgenol 2011;196:W421‑5.
6. Steilen D, Hauser R, Woldin B, Sawyer S.Chronic neck pain:
Making the connection between capsular ligament laxity
and cervical instability. Open Orthop J 2014;8:326‑45.
7. Kehl AS, Corr M, Weisman MH. Review: Enthesitis: New
insights into pathogenesis, diagnostic modalities, and
treatment. Arthritis Rheumatol 2016;68:312‑22.
8. Voudouris KP, Sidiropoulos P, Vounotrypidis P,
Arvanitakis M. Ethesial fibrocartilage‑bone interaction:
A radiographic study of selected sites of nonsynovial
peripheral enthesopathy. J Musculoskel Neuron Interact
2003;3:89‑100.
9. Harrison DD, Colloca CJ, Betz J, Janik TJ, Holland B.
Repeatability over time of posture, radiograph positioning,
and radiograph line drawing: An analysis of six control
groups. J Manipulative Physiol Ther 2003;26:87‑98.
10. Sheikhhoseini R, Shahrbanian S, Sayyadi P, O’Sullivan K.
Effectiveness of therapeutic exercise on forward head
posture: A systematic review and meta‑analysis. J Manip
Physiol Ther 2018;41:530‑9.