Sensorimotor Neck Study, towards an Objective Approach of non-specific neck pain.

Non-specific neck pain is a widespread complaint. Non-specific neck pain is a
widespread complaint. The overall prevalence of neck pain in the general
population ranges between 0.4% and 86.8% (mean: 23.1%) with an estimated 1 year
incidence of neck pain from available studies ranges between 10.4% and
21.3%.(Hoy, Protani et al. 2010) . The group of suffering from neck pain seems
to be heterogeneous, no age group, high or low anxiety levels or occupation is
spared (wright et al., 1999).
In people with non-specific neck pain the mobility and stability of the
cervical spine is often decreased. In addition regularly also vertigo,
dizziness and difficulty keeping balance is reported (Eck et al. 2001).
Treleaven (2008) revealed that sensorimotor disturbances could play a role in
non-specific neck pain. The term sensorimotor describes all the afferent,
efferent, and central integration and processing components involved in
maintaining stability in the postural control system through intrinsic motor
control properties (Kristjansson et al., 2009).
Afferent information from the vestibular, visual and proprioceptive system of
the cervical spine plays an important role in the sensorimotor control of
posture and head and eye movements (Treleaven, 2008). The cervical suboccipital
muscles rely on afferent and efferent information from the central nervous
system, the visual and the vestibular apparatus (Bolton, 1998, Corneil, 2002,
Helstrom
2002). One of the reflexes involved in the cervical afferents is the cervical
ocular reflex (COR) (Kelders et al., 2006). The COR is interrelated with the
vestibule ocular reflex (VOR) and the optokinetic reflex (OKR) this to ensure
clear vision with movement (Mergner, 1998).
Stimulation of cervical muscle spindle afferents in asymptomatic individuals
through vibration of neck muscles induces disturbances in eye and head
position, changes in body sway and the pace and direction of gait and running
(Bove 2002, Courtine 2003).
In patients with cervical sensory dysfunction, disturbances in cervical joint
position sense (Heikkila, 1996, Treleaven 2003), postural stability (Sjostrom
2003, Treleaven, 2005 a,b, Field 2007) and oculomotor control as altered smooth
pursuit (Tjell, 2003, Treleaven 2005 a,b, Storaci 2006) can be present.
Deficits in tests of head and eye movement, an increased gain of the COR and
postural stability are found in patients with neck disorders of traumatic
origin in association with dizziness (Tjell, 2003, Treleleaven, 2003, 2005a,b,
Montfoort, 2006). There is some preliminary evidence that these deficits can
also be present in patients with idiopathic neck pain (Kristjansson, 2003,
Tjell, 2003, Field, 2007).
Research also has provided evidence of specific deficits in the coordination of
the deep and superficial cervical muscles (Jull, 2004). Studies have revealed
increased electromyographic amplitude of the large superficial
sternocleidomastoid and anterior scalene muscles in patients with neck pain
(Falla, 2004, Jull 2004). This was associated with reduced activation of the
deep cervical flexors, longus capitis and longus colli and reduced range of
cranio cervical flexion (Falla, 2004).
A vast majority of the research that is done throughout the last decade has
focused on subgroups of patients with neck pain such as people suffering from
neck pain after a car accident or people with chronic neck pain. The deficits
in sensorimotor control and accompanying symptoms such as dizziness are more
obvious in this group (Tjell, 2003, Treleaven 2003, 2005 a,b, Field, 2007).
Nevertheless the main group of patients with neck pain has no history of a car
accident or neck pain in a chronic sense (Feyer et al., 2006).
The lack of research which investigates the relationship between non-specific
neck pain and a disturbed sensorimotor control and also not being able to make
a precise analysis of which system within the sensorimotor system is disturbed
makes it hard to make an exact diagnosis. The effect of this inability is that
it is difficult to come to a targeted therapy for non specific neck pain.
The hypothesis of this study is that reflexive eye movement measurements can
assist to make the connection between functional impairments and symptoms for
non specific pain patients. Recording of eye reflexes might help to objectively
assess the severity of complaints of neck pain patients.

The overall aim is to develop an objective symptom profile of non specific
neckpain patients which addresses more facets of the health problem, including
sensorimotor dysfunction. The first stage is the establishment of an objective
quantification of sensorimotor dysfunction in people with non specific neckpain.

The main research question is:
Is there a difference in sensorimotor control in people with non specific neck
pain compared to people without any neck pain?

In order to get insight into the different elements which are related to the
sensorimotor control related to non specific neck pain it is necessary
to answer the following questions:
Is there a significant difference between the gain (ratio between eye and
stimulus movement) of the cervico-ocular reflex (COR), the vestibulo-ocular
reflex (VOR) and the optokineticreflex (OKR) in subjects (aged 18-60) with and
without non specific neck pain?
Is there a significant difference in the outcome of the smooth pursuit neck
torsion test (SPNT) in people with non-specific neck pain compared to people
without non-specific neck pain?
Is there a significant difference in cervical joint position error in people
with non-specific neck pain in contradiction to people without non-specific
neck pain?
Is there a significant difference in the active movement of the upper cervical
spine (C0-C3) and the mid cervical spine (C3-C7) in people with and without
non-specific neck pain?
Is there a correlation between the synergy of the gain of the eye reflexes
(COR, VOR and OKR) and cervical functionality (range of motion, joint
reposition error and the active movement of the upper cervical spine and the
mid cervical spine
Is there a correlation between the perceived impairments (Vas, Neck Disability
Index and Dizziness Handicap Inventory) and objective parameters (COR, VOR, OKR
and spnt)?

The study design is a cross sectional design.
All the measurements will take place at the same time.
This applies to the group of people with non-specific neck pain and the control
group

There are no risks related to this study. There are no related physical of
psychological side effects to the measurements. The burden of participating is
just the invested time. All subjects undergo one measurement which last
approximately an hour each.