Understanding the complete pathophysiology of chronic mild to moderate neck pain: Implications for the inclusion of a comprehensive sensorimotor evaluation

Abstract

BACKGROUND:

Inconsistencies in the literature concerning the effect of neck pain have led to a lack of understanding concerning the complete pathophysiology of neck pain. While the effect of neck pain on motor function as measured by active range of motion and isometric neck strength is well documented the effect of neck pain on sensory measures such as tactical acuity and neck reposition error (NRE) remain poorly understood.

OBJECTIVE:

The purpose of this study was to evaluate a combined sensorimotor evaluation to explore the potential benefits of incorporating both sensory and motor task into a physical evaluation of neck pain suffers to gain an added knowledge of the complete pathophysiology of their health status.

METHODS:

A cross-sectional study that measured neck joint reposition error, tactical acuity, neck isometric strength and range of motion in 40 volunteer participants (22 pain, 18 control).

RESULTS:

A statistically significant increase in NRE in flexion (2.75 ${}^{\circ}$ $\pm$ 1.52 ${}^{\circ}$ vs. 4.53 ${}^{\circ}$ $\pm$ 1.74 ${}^{\circ}$ and in extension (3.78 ${}^{\circ}$ $\pm$ 1.95 ${}^{\circ}$ vs 5.77 ${}^{\circ}$ $\pm$ 2.73 ${}^{\circ}$ in participants suffering from neck pain was observed. Additionally, the dermatome C5 was found to be the most affected. No differences were found in neck strength or neck range of motion between healthy controls and patients with chronic moderate neck pain.

Keywords

Tactile acuity neck reposition error isometric neck strength range of motion two-point discrimination proprioception training

1. Introduction

Neck pain is reported to effect 33% of the population each year [1]. That percentage is estimated to affect 16% of people between the age of eighteen and twenty-nine and increases with age [1]. The source of neck pain is often illusive and can come as a result of varying pathologies leading to the common use of the term “non-specific neck pain”. These pathologies include whiplash [2], poor posture [3], and high velocity sports injuries i.e. concussion [4, 5, 6, 7]. Sensory and motor function are important in maintaining postural control allowing the neck to perform movements required to perform ADLs such as driving a motor vehicle and to protect against potential sporting hazards such as tackling in football or heading in soccer [8]. Structures involved in appropriate sensory and motor function include muscle spindles, articular receptors, muscles, efferent motor pathways, afferent sensory pathways, connective tissue and bony articulations which work synergistically to support the head [9].

Head position sense is controlled in part by passive constraints such as ligaments, tendons and connective tissues and the architecture of each individual cervical vertebrae, and secondly by afferent feedback from muscle spindles in the cervical musculature which send messages to the sensory cortex and motor cortex respectively via the cerebellum and thalamus [9]. However, it has been reported that the osteoligamentous structures of the cervical spine contribute only a mere 20% of the minimally needed mechanical stability of the cervical spine [10], suggesting that the remaining 80% of the mechanical load is managed by the cervical musculature.

Damage to the cervical musculature has been reported to interrupt the communication between muscle spindles in the cervical musculature and the somatosensory cortex in the brain leading to decreases in neck function [11]. Disruption due to neck pain has been reported to effect neck muscle strength [12, 13], neck muscle size and thickness [14, 15, 16], range of motion [17, 18], neck reposition error (NRE) [8, 19], and tactile acuity (TA) of cervical dermatomes [20]. NRE and neck range of motion help to analyze the integration between sensory and motor function creating highly integrated sensorimotor movements [21, 22], while isometric neck strength is primarily a measure of motor function and TA a measure of sensory function [23].

In addition to sensory dysfunction, motor dysfunction as identified by deficits isometric neck strength and active range of motion have been reported in chronic neck pain sufferers [12, 13, 17, 18]. However, the role sensory disturbances contribute to cervical motor dysfunction is poorly understood as previous research has typically focused on evaluating a single aspect of cervical function i.e. decreases in strength or increases in position error [24]. Recent reports identifying balance disturbances and oculomotor disturbances in conjunction with neck reposition error in patients suffering from chronic neck pain have highlighted the importance of understanding the complete pathophysiology of neck pain and its implications [2, 19, 24].

Increases in NRE have been reported in patients suffering from neck pain and are indicative of a difference between an individual’s “perceived” head position and the actual position of the head therefore decreasing the ability to appropriately position the head in a desired position [19]. Similarly decreased sensation has been reported in patients suffering from complex pain associated disorders and are indicative of decreased sensorimotor function [25]. The primary role of NRE is to assess the afferent input from the muscle spindles in the cervical musculature by measuring the ability of the head to return to normal resting posture following movement, thereby providing clinicians a method to measure proprioception in the neck [7, 8]. NRE has been reported to be higher in patients suffering from pain related symptoms as a result of disruption of the ascending sensory pathway to the receptors and on to the sensory and motor cortexes [7, 21]. The reliability of NRE testing has also been explored and found to be adequately reliable to produce significant results [19].

TA measures the perception or sharpness of the sense of touch [26]. Proper mechanoreceptor activity in the neck and surrounding areas is critical to sense touch and contribute to neck function [26]. The most common method of measuring TA is the two-point discrimination threshold test To our knowledge no research has compared the effect of mild to moderate chronic neck pain on the sensation of cervical dermatomes C-4 through C-8 which radiate down the shoulder and arm in conjunction with NRE to evaluate the role of decreased sensation in overall neck function and the potential implications for rehabilitation of the cervical spine in chronic pain suffers.

The purpose of this examination was to explore the use of a combined sensorimotor evaluation using both sensory and motor test to evaluate cervical dysfunction in patients with mild neck pain and the potential effectiveness of using this measures to track progress through out a treatment protocol in neck pain suffers.

2. Methods

2.1 Subjects

Forty subjects (22 females, 18 males) were recruited from a convince sample of university students and staff. Subjects were divided into two groups; a pain group and a healthy group. Twenty-two subjects participated in the pain group (13 females, 9 males; age 25.5 $\pm$ 9.75 years; weight 77.76 $\pm$ 15.56 kg; height 172.36 $\pm$ 10.19 cm). Eighteen subjects participated in the healthy control group (9 females, 9 males; age 23 $\pm$ 5.91 years; weight 70 $\pm$ 13.05 kg: height 174.42 $\pm$ 10.19 cm). All subjects were required to sign a consent form approved by the ethical board comprised of members of the university’s IRB prior to participation in the study.

2.2 Inclusion criteria

The study design was a cross-sectional study. Subjects were assigned to a group based on their Neck Disability Index score [27]. The neck disability index scores from 0–50 and consist of 10 sections, each section represents a functional task i.e. pain intensity, personal care, lifting, work, headaches, reading, recreation, driving, sleeping and concentration. Each section is scored on a scale from 0–5 ranging from no pain during the activity (0) to unable to perform activity (5) and then the total score across each section is summed. All participants scoring above an 8 were assigned to the neck pain group. Participants scoring a 4 or below were assigned to the control group. Two patients scoring $>$ 5 and $<$ 8 were excluded from the study. Previous literature has suggested a score of $>$ 8 is indicative of moderate disability while a score $>$ 15 has been identified as significant neck functional disability due to neck pain [28]. Visual analogue scale (VAS) scores measured on a 100 mm line were also collected as an indicator of pain in both groups. The VAS was anchored on the left with the words, “NO Pain” and on the right with “Worst Imaginable Pain”. Each group’s pain indicator scores are shown in Table 1. The researcher that performed the NRE and TA measurements was blind to each subject’s group to avoid any researcher bias.

Table 1
Pain measures

	Healthy group	Pain group	$P$ -values
	Mean $\pm$ SD	Mean $\pm$ SD
Visual analog	3.83 $\pm$ 6.86	28.68 $\pm$ 15.24	* $<$ 0.0001
scale (mm 1–100)
Neck disability	1.06 $\pm$ 1.21	10.73 $\pm$ 3.21	* $<$ 0.0001
index (1–50)

*Statistically significant difference between two groups.

2.3 Two-point discrimination (tactile acuity)

Thresholds were measured at each dermatome from C3–C8. Measurements were taken using a Baseline Discriminator Aesthesiometer (Electro Medical, Marietta, GA). Dermatomes were measured bilaterally and then summed and divided to represent the average between each side. Due to the limitations that have been identified with two-point discrimination the following parameters were followed to limit inconstancies between measurements. All measurements were taken with a vertical orientation [29]. The tips of the baseline two-point discriminator device were filed slightly to create a more blunt edge to avoid any sensation of sharpness or pain [29]. When two stimuli were presented special care was taken to make contact at the same time with both points [26]. The pressure applied to the skin was kept to about 10 grams or that equal to the first blanching of the skin [26]. The threshold was determined by the smallest distance between the two stimuli that the participant could still detect two distinct stimuli rather than just one [29]. For each stimulus given the participant was asked to respond either one or two depending on wither one stimulus was perceived or two. The starting distance for the two-point discrimination threshold was 10 mm for dermatomes C6–C8. Initial pilot data of 5 individuals showed that dermatomes C3–C5 had a much larger threshold and so the starting threshold was set at 30 mm. If the first test was incorrectly identified the distance was increased by 5 mm until the first correct identification of two points was obtained. The test started after the initial correct identification of two distinct stimuli. Adjustments to the distance between the two points were made as follows: for each correct answer of either one or two stimuli the distance between the two points was reduced by 2 mm and for each incorrect answer the distance was increased by 1 mm. Participants were given one or two stimuli until 5 total incorrect answers were given. Both the examiner and participant were seated with their arms supported on a table. The following landmarks were used to identify each cervical dermatome measured: C3–3 cm above the mid-clavicular line, C4-anterior edge of the acromion, C5-the lowest point of the deltoid insertion, C6-the thenar eminence, C7-volar surface of the base of the 3 ${}^{\rm rd}$ digit, and C8-volar surface of the base of the 5 ${}^{\rm th}$ digit [30]. Two point discrimination thresholds were taken by the same researcher for all participants. ICC values for this researcher were calculated and ranged from 0.89–0.92 during pilot testing.

Figure 1.

Joint reposition error test.

2.4 Neck reposition error

The procedures established by Revel et al. with slight modifications were followed to collect NPE [21]. Each participant was positioned exactly 90 cm from a target placed on the wall and strapped into a straight backed chair to limit accessory movement of the torso see Fig. 1. Following positioning the participants were instructed to position their head in the most comfortable natural resting head position staring straight at the wall. Blacked-out glasses were worn by each participant to occlude their vision to insure that they could not see the target during each trial. The participant was asked to maximally flex their neck and then actively return to the starting position. The point where the laser came to a rest on the target was marked and the distance from the center point mas measured and marked as the error. The same process was repeated with the participant extending the neck, rotating the neck to the left and rotating to the right representing both horizontal and vertical movements. No practice trials were allowed and the mean of 8 trials was used in the analysis as 8 trials had previously been identified to be the maximum number of trials required to obtain optimal reliability [31]. The degrees of error were derived by calculating the arc tangent of the distance between the center point and the marking on the target in centimeters divided by 90 centimeters (the distance the subject was from the target).

2.5 Range of motion

Range of motion measurements were taken using cervical range of motion instrument 3 (Performance Attainment Associates, Manitowoc, WI). Range of motion was taken for flexion, extension, left and right lateral flexion and left and right rotation. During the range of motion measurements participants were seated in a straight back chair and strapped in to minimize any accessory movements at the torso. The intra-tester and inter-tester reliability have previously been reported to be reliable in both normal and chronic neck pain groups with high ICC coefficients ranging from 0.75–*0.92 [32].

2.6 Isometric strength

Isometric strength was measured using a microFET2 hand held dynamometer (Hoggan Health, Sandy, UT). To minimize examiner error the hand held dynamometer was mounted to a mobile device. This device allowed for the location and orientation of the dynamometer to be adjusted both vertically and horizontally and to be lined up with the proper landmark for measuring isometric strength in each direction. The participants were then seated and strapped into a straight backed chair next to the device. Flexion, extension, left and right lateral flexion and left and right rotation were measured. To measure flexion the dynamometer was aligned with the forehead of the individual and they were instructed to, “over the course of 5 seconds try as hard as you can to bring your chin down to your chest”. This procedure was repeated in extension with the dynamometer being aligned with the occiput. For lateral flexion the dynamometer was aligned just superior to the ear and for right and left rotation the dynamometer was aligned slightly superior to the pterion. Three trials were performed for each motion and the average of the highest was used as the maximum isometric contraction. Pilot data revealed that 3 trials was sufficient to attain reliable measurements with intra-session ICC values ranging from 0.88–0.95 for 5 pilot subjects.

2.7 Statistical analysis

There were two groups of subjects, classified as either with neck pain or healthy. The most important response variables included joint reposition error (four variables: flexion, extension, right and left), and tactile acuity at six cervical dermatomes. A standard independent two-sample t-test with equal variance was reported for each cervical dermatome and for each movement with joint reposition error as well as peak isometric strength and cervical R.O.M.

Table 2
Tactile acuity threshold (mm)

	Healthy group	Pain group	$P$ -values	T-test	df	95% CI
	Mean $\pm$ SD	Mean $\pm$ SD				Lower	Upper
C3	24.00 $\pm$ 7.43	27.41 $\pm$ 6.36	0.1259	$-$ 1.565	38	$-$ 7.82	1.00
C4	29.25 $\pm$ 7.39	35.43 $\pm$ 12.81	0.0778	$-$ 1.813	38	$-$ 13.09	$-$ 0.72
C5	35.25 $\pm$ 10.06	45.86 $\pm$ 13.54	*0.0089	$-$ 2.757	38	$-$ 18.41	$-$ 2.82
C6	3.86 $\pm$ 1.66	4.02 $\pm$ 1.29	0.7306	$-$ 0.347	38	$-$ 1.10	0.78
C7	4.64 $\pm$ 1.77	5.02 $\pm$ 2.06	0.5361	$-$ 0.624	38	$-$ 1.63	0.86
C8	4.36 $\pm$ 1.40	4.90 $\pm$ 1.64	0.2762	$-$ 1.105	38	$-$ 1.53	0.45

*Significant difference at 0.05 level.

Table 3

Neck reposition error

	Healthy group	Pain group	$P$ -values	T-test	df	95% CI
	Mean $\pm$ SD	Mean $\pm$ SD				Lower	Upper
Flexion	2.75 $\pm$ 1.52	4.53 $\pm$ 1.71	*0.0015	$-$ 3.433	38	$-$ 2.83	$-$ 0.73
Extension	3.78 $\pm$ 1.95	5.77 $\pm$ 2.73	*0.0133	$-$ 2.598	38	$-$ 3.54	$-$ 0.44
Right rotation	3.43 $\pm$ 1.45	3.38 $\pm$ 1.53	0.9239	0.096	38	$-$ 0.92	1.01
Left rotation	4.08 $\pm$ 1.71	5.47 $\pm$ 3.77	0.1558	$-$ 1.448	38	$-$ 3.34	0.55

*Significant at level of 0.05.

Table 4

Neck range of motion in degrees

	Healthy group	Pain group	$P$ -values	T-test	df	95% CI
	Mean $\pm$ SD	Mean $\pm$ SD				Lower	Upper
Flexion	62.15 $\pm$ 10.18	55.68 $\pm$ 11.62	0.072	1.850	38	$-$ 0.61	13.54
Extension	74.07 $\pm$ 10.33	74.82 $\pm$ 18.03	0.877	$-$ 0.155	38	$-$ 10.45	8.96
Right rotation	57.76 $\pm$ 5.45	59.01 $\pm$ 8.63	0.596	$-$ 0.535	38	$-$ 6.00	3.49
Left rotation	57.42 $\pm$ 7.39	57.86 $\pm$ 9.33	0.873	$-$ 0.161	38	$-$ 5.92	5.54
Left lateral flexion	41.97 $\pm$ 8.77	45.41 $\pm$ 9.00	0.232	$-$ 1.214	38	$-$ 9.16	2.29
Right lateral flexion	44.53 $\pm$ 8.10	45.63 $\pm$ 11.23	0.730	$-$ 0.348	38	$-$ 7.50	5.31

Table 5

Neck isometric strength (Kg)

	Healthy group	Pain group	$P$ -values	T-Test	df	95% CI
	Mean $\pm$ SD	Mean $\pm$ SD				Lower	Upper
Flexion	12.63 $\pm$ 6.28	11.33 $\pm$ 6.81	0.537	0.623	38	$-$ 2.93	5.53
Extension	14.77 $\pm$ 5.80	13.45 $\pm$ 7.554	0.546	0.609	38	$-$ 3.07	5.71
Right rotation	10.55 $\pm$ 5.70	9.35 $\pm$ 3.70	0.425	0.807	38	$-$ 1.82	4.23
Left rotation	10.24 $\pm$ 5.31	8.87 $\pm$ 4.00	0.356	0.935	38	$-$ 1.60	4.36
Left lateral flexion	12.24 $\pm$ 5.34	10.84 $\pm$ 5.44	0.418	0.818	38	$-$ 2.07	4.88
Right lateral flexion	12.03 $\pm$ 5.86	10.57 $\pm$ 5.35	0.415	0.824	38	$-$ 2.13	5.05

3. Results

The results of the two-point discrimination test are displayed in Table 2. C5 dermatome showed a significant level of difference in sensation between the neck pain group and the healthy group. While none of the other levels achieved a statistical significant difference the absolute mean in two-point discrimination threshold was higher in the pain group in each of the six measured dermatomes. Results for NRE can be found in degrees in Table 3. Neck flexion and extension were found to vary significantly between the healthy and neck pain groups; however, right rotation, left rotation showed no significant differences between the two groups. The values for range of motion and neck isometric strength are shown in Tables 4 and 5 respectively. No significant difference was found between the neck pain group and healthy group range of motion or isometric strength measurement in any movement direction.

4. Discussion

In spite of the fact that the mean NDI for our moderate chronic neck pain participants was less than 11 points, statistically significant differences between our chronic moderate neck pain group and the heathy controls were observed in NRE for flexion and extension as well as sensation at the C5 dermatome. Similar to previous research in which differences in NRE ranging from 3–6 ${}^{\circ}$ have been observed our results suggest the NRE test is a sensitive indicator of sensorimotor disturbances in the presence of even moderate chronic neck pain [19, 21, 24, 33]. This is significant as the previous cut-off value of the NDI identified to be associated with disability has been reported to be 15 points [28]. Our results demonstrate moderate neck pain may be sufficient to lead to decreases in sensorimotor function if experienced over a chronic period of time in the case of this article a minimum of 12 weeks.

The dermatome identified to be most affected by the moderate neck pain was C5. This suggests that the effect of neck pain on tactile acuity is not limited to the area directly surrounding the neck, but may also effect the upper arms as the sensory afferents associated with sensation of the upper arm pass through the neck and pain may at the neck may alter neuronal activity. Previous, literature on the effects of neck pain on tactile sensation are limited however preliminary data using monofilaments has shown so indication of impaired sensory function in neck pain suffers [30]. This evidence combined with our findings suggests that while evaluating neck sensation of an individual following a neck injury, in the presence of neck pain, it may be of interest to measure the sensation of the surrounding dermatomes and not limit the examination to dermatomes C3, C4 surrounding the neck.

Isometric neck strength as well as range of motion have also been reported to be affected by neck pain [12, 34, 35, 36]. Our results however, showed no significant differences in cervical range of motion or isometric neck strength in of the movements measured suggesting that perhaps moderate neck pain is not sufficient to alter the descending motor efferent neurons from the motor cortex to the musculature of the cervical spine. This evidence suggests that perhaps a more inclusive examination including NPE, tactile acuity, cervical range of motion and isometric neck strength may give a more comprehensive view of the patients symptoms prior to treatment and may allow for a more detailed picture of a patient’s neck dysfunction.

Clinical test such as NPE and two-point discrimination allow clinicians to identify deficiencies in these afferent pathways and respective sensory receptors. Increased understanding of the effect neck pain has on these afferent pathways and in turn on neck function has led to a recent increase in vestibular and cervicogenic rehabilitation as a treatment of neck pain as well as the treatment of concussion related symptoms [8]. Recent evidence suggests that neck pain sufferers may benefit from training exercises designed to improve neck position sense and sensation as well as restore normal muscle strength. The two-point discrimination threshold test offers an inexpensive and rapid method for measuring the tactile acuity of the associated dermatomes of the neck within a clinical setting [29].

5. Conclusion

In spite of using a population with mild to moderate chronic neck pain both the Two-Point Discrimination Test and the NRE appear to give clinicians additional inexpensive and quick objective data that can be used in the diagnostic portion of an examination when combined with other measures such as range of motion and isometric neck strength. The results of such diagnostic exams could in turn be used in designing a rehabilitation program and assisting in monitoring progress during the course of treatment of cervical pain. Further research is needed to establish the clinical significance of this information.

Limitations

Limitations to this study include variation in the duration and intensity of pain for each participant in the pain group. The mean NDI value of our chronic pain group was below the reported cut-off value of the NDI to detect pain associate with disability. All participants had experienced neck pain $>$ 12 weeks but no additional data was gathered with regards to duration or location of chronic pain. Additionally, no postural assessments were performed on the participants in this study and it may be possible that poor posture in the initial resting head position lead to greater neck reposition error rather than the presence of pain. This however was controlled for in our methodology to the best of our ability.

Conflict of interest

The authors declare no conflicts of interest.

References

Croft

Lewis

Papageorgiou

Thomas

Jayson

MIV

Macfarlane

, et al. Risk factors for neck pain: A longitudinal study in the general population. Pain. 2001; 93(3): 317-25.

Sjolander

Michaelson

Jaric

Djupsjobacka

. Sensorimotor disturbances in chronic neck pain – range of motion, peak velocity, smoothness of movement, and repositioning acuity. Man Ther. 2008; 13(2): 122-31.

Cunha

Burke

Franca

Marques

. Effect of global posture reeducation and of static stretching on pain, range of motion, and quality of life in women with chronic neck pain: A randomized clinical trial. Clinics (Sao Paulo). 2008; 63(6): 763-70.

Leddy

Baker

Merchant

Picano

Gaile

Matuszak

, et al. Brain or strain? Symptoms alone do not distinguish physiologic concussion from cervical/vestibular injury. Clinical Journal of Sport Medicine. 2015; 25(3): 237-42.

Ellis

Leddy

Willer

. Physiological, vestibulo-ocular and cervicogenic post-concussion disorders: An evidence-based classification system with directions for treatment. Brain Inj. 2015; 29(2): 238-48.

Marshall

Vernon

Leddy

Baldwin

. The role of the cervical spine in post-concussion syndrome. Physician Sportsmed. 2015; 43(3): 274-84.

Kristjansson

Treleaven

. Sensorimotor function and dizziness in neck pain: Implications for assessment and management. J Orthop Sports Phys Ther. 2009; 39(5): 364-77.

Schneider

Meeuwisse

Nettel-Aguirre

Barlow

Boyd

Kang

, et al. Cervicovestibular rehabilitation in sport-related concussion: A randomised controlled trial. Br J Sports Med. 2014; 48(17): 1294-U55.

Armstrong

McNair

Taylor

. Head and neck position sense. Sports Med. 2008; 38(2): 101-17.

10.

Panjabi

Cholewicki

Nibu

Grauer

Babat

Dvorak

. Critical load of the human cervical spine: An in vitro experimental study. Clinical Biomechanics. 1998; 13(1): 11-7.

11.

Loudon

Ruhl

Field

. Ability to reproduce head position after whiplash injury. Spine. 1997; 22(8): 865-8.

12.

Cagnie

Cools

De Loose

Cambier

Danneels

. Differences in isometric neck muscle strength between healthy controls and women with chronic neck pain: The use of a reliable measurement. Arch Phys Med Rehabil. 2007; 88(11): 1441-5.

13.

Eckner

Joshi

Richardson

Ashton-Miller

. Effect of neck muscle strength and anticipatory cervical muscle activation on the kinematic response of the head to impulsive loads. Am J Sports Med. 2014; 42(3): 566-76.

14.

Rezasoltani

Ahmadipoor

Khademi-Kalantari

Javanshir

. The sign of unilateral neck semispinalis capitis muscle atrophy in patients with chronic non-specific neck pain. J Back Musculoskel Rehabil. 2012; 25(1): 67-72.

15.

McPartland

Brodeur

Hallgren

. Chronic neck pain, standing balance, and suboccipital muscle atrophy – A pilot study. J Manipulative Physiolo Ther. 1997; 20(1): 24-9.

16.

Rezasoltani

Ali-Reza

Khosro

Abbass

. Preliminary study of neck muscle size and strength measurements in females with chronic non-specific neck pain and healthy control subjects. Man Ther. 2010; 15(4): 400-3.

17.

Lee

Nicholson

Adams

. Cervical range of motion associations with subclinical neck pain. Spine (Phila Pa 1976). 2004; 29(1): 33-40.

18.

Lee

Nicholson

Adams

. Neck muscle endurance, self-report, and range of motion data from subjects with treated and untreated neck pain. J Manipulative Physiol Ther. 2005; 28(1): 25-32.

19.

Treleaven

Jull

LowChoy

. The relationship of cervical joint position error to balance and eye movement disturbances in persistent whiplash. Man Ther. 2006; 11(2): 99-106.

20.

Song

Cohen

Ament

Vulpe

Schandler

. Two-point discrimination thresholds in spinal cord injured patients with dysesthetic pain. Paraplegia. 1993; 31(8): 425-93.

21.

Revel

Andredeshays

Minguet

. Cervicocephalic kinesthetic sensibilitity in patients with cervical pain. Arch Phys Med Rehabil. 1991; 72(5): 288-91.

22.

Pleger

Tegenthoff

Ragert

Forster

Dinse

Schwenkreis

, et al. Sensorimotor returning in complex regional pain syndrome parallels pain reduction. An Neurology. 2005; 57(3): 425-9.

23.

Sterling

Jull

Vicenzino

Kenardy

Darnell

. Development of motor system dysfunction following whiplash injury. Pain. 2003; 103(1-2): 65-73.

24.

Treleaven

Jull

Sterling

. Dizziness and unsteadiness following whiplash injury: Characteristic features and relationship with cervical joint position error. J Rehabilitation Med. 2003; 35(1): 36-43.

25.

Lee

Teng

Chai

Wang

. Test-retest reliability of cervicocephalic kinesthetic sensibility in three cardinal planes. Man Ther. 2006; 11(1): 61-8.

26.

Lundborg

Rosen

. The two-point discrimination test – Time for a re-appraisal? J Hand Surg-Br Eur Volume. 2004; 29B(5): 418-22.

27.

Vernon

Mior

. The neck disability index – A study of reliablity and validity. J Manipulative Physiolog Therapeut. 1991; 14(7): 409-15.

28.

Kato

Takeshita

Matsudaira

Tonosu

Hara

Chikuda

. Normative score and cut-off value of the neck disability index. J Orthopaedic Sci. 2012; 17(6): 687-93.

29.

Tong

Mao

Goldreich

. Two-point orientation discrimination versus the traditional two-point test for tactile spatial acuity assessment. Frontiers Human Neurosci. 2013; 7.

30.

Voerman

van Egmond

Crul

BJP

. Normal values for sensory thresholds in the cervical dermatomes – A critical note on the use of Semmes-Weinstein monofilaments. Am J Physical Med Rehabilit. 1999; 78(1): 24-9.

31.

Pinsault

Fleury

Virone

Bouvier

Vaillant

Vuillerme

. Test-retest reliability of cervicocephalic relocation test to neutral head position. Physiother Theory Pract. 2008; 24(5): 380-91.

32.

Law

EYH

Chiu

TT-W

. Measurement of cervical range of motion (CROM) by electronic CROM goniometer: A test of reliability and validity. Journal of Back and Musculoskeletal Rehabilitation U6 Journal Article. 2013; 26(2): 141.

33.

Revel

Minguet

Gergoy

Vaillant

Manuel

. Changes in cervicocephalic kinestheesia after a proprioceptive rehabilitatiion program in patients with neck pain – A randomized controlled-study. Arch Phys Med Rehabilit. 1994; 75(8): 895-9.

34.

Andersen

Kjaer

Andersen

Hansen

Zebis

Hansen

, et al. Muscle activation during selected strength exercises in women with chronic neck muscle pain. Phys Ther. 2008; 88(6): 703-11.

35.

Hudes

. The Tampa Scale of Kinesiophobia and neck pain, disability and range of motion: A narrative review of the literature. J Can Chiropr Assoc. 2011; 55(3): 222-32.

36.

Ylinen

Takala

Kautiainen

Nykanen

Hakkinen

Pohjolainen

, et al. Association of neck pain, disability and neck pain during maximal effort with neck muscle strength and range of movement in women with chronic non-specific neck pain. Eur J Pain. 2004; 8(5): 473-8.

Understanding the complete pathophysiology of chronic mild to moderate neck pain: Implications for the inclusion of a comprehensive sensorimotor evaluation

Abstract

BACKGROUND:

OBJECTIVE:

METHODS:

RESULTS:

Keywords

1. Introduction

2. Methods

2.1 Subjects

2.2 Inclusion criteria

Table 1 Pain measures

2.5 Range of motion

2.6 Isometric strength

2.7 Statistical analysis

Table 2 Tactile acuity threshold (mm)

4. Discussion

5. Conclusion

Limitations

Conflict of interest

References

Table 1
Pain measures

Table 2
Tactile acuity threshold (mm)