Association between cervicocephalic kinesthetic sensibility and frequency of subclinical neck pain

The cervico-ocular reflex changes following treatment in individuals with subclinical neck pain: a randomized control trial

Individuals with subclinical neck pain (SCNP) exhibit altered cerebellar processing, likely due to disordered sensorimotor integration of inaccurate proprioceptive input. This association between proprioceptive feedback and SMI has been captured in cervico-ocular reflex (COR) differences where SCNP showed higher gain than healthy participants. Previous neurophysiological research demonstrated improved cerebellar processing in SCNP participants following a single treatment session, but it is unknown whether these neurophysiological changes transfer to cerebellar function. In a parallel group, randomized control trial conducted at Ontario Tech University, 27 right-hand dominant SCNP participants were allocated to the 8-week chiropractic care (n = 15; 7M & 8 F) or 8-week control (n = 12; 6M & 6 F) group. COR gain (ratio of eye movement to trunk movement) was assessed using an eye-tracking device at baseline and at post 8-weeks (treatment vs. no treatment). COR gain (10 trials): participants gazed at a circular target that disappeared after 3 s, while a motorized chair rotated their trunk at a frequency of 0.04 Hz, with an amplitude of 5º, for 2 minutes. A 2 × 2 repeated measures ANOVA was performed. COR gain was significantly reduced following 8-weeks of chiropractic care compared to the SCNP control (8-weeks of no treatment) group (p = 0.012, ηp2 = 0.237). The decrease in COR gain following treatment is likely due to normalized proprioceptive feedback from the neck, enabling improved processing and integration within the flocculonodular lobe of the cerebellum.

A cluster analysis of cervicocephalic kinesthetic sensibility in persons with nonspecific neck pain

INTRODUCTION

Inter-individual variability may contribute to impaired cervicocephalic kinesthetic sensibility (CKS) in patients with nonspecific neck pain.

OBJECTIVES

To identify subgroups of participants with nonspecific neck pain based on cervical joint position errors (JPEs) and to determine potential factors associated with identified subgroups.

METHODS

One hundred participants with nonspecific neck pain (unidentified pathoanatomical cause) and 50 controls were recruited. JPEs were measured in cervical extension and rotation, using a laser pointer. JPEs were expressed as absolute (AEs), constant (CEs), and variable (VEs) errors. Clinical characteristics were pain intensity, duration, disability, side of pain, dizziness, psychological features, and range of motion. All tests were performed within 1 day. A cluster analysis was conducted based on AEs. A logistic regression was used to identify factors associated with the cluster groups.

RESULTS

Analysis divided neck pain participants into two groups: cluster 1 with greater impaired CKS (n = 36) and cluster 2 with lesser impaired CKS (n = 64). The AEs (all cervical movements) and CE (left rotation) were larger in cluster 1 than 2 (p ≤ .002). Overall, participants in clusters 1 and 2 had larger AEs, CEs, and VEs than controls (p ≤ .04). The presence of dizziness was a risk factor associated with cluster 1 (OR=2.5, p = .04). The other characteristics were not associated with the cluster groups (p ≥ .09).

CONCLUSION

The AEs identified two subgroups of patients with nonspecific neck pain. Participants in subgroup 1 had greater impaired CKS, and participants in subgroup 2 had lesser impaired CKS. Dizziness was a potential risk factor associated with greater impaired CKS.

Impact of subclinical neck pain on eye and hand movements in goal-directed upper limb aiming movements

Individuals with untreated, mild-to-moderate recurrent neck pain or stiffness (subclinical neck pain (SCNP)) have been shown to have impairments in upper limb proprioception, and altered cerebellar processing. It is probable that aiming trajectories will be impacted since individuals with SCNP cannot rely on accurate proprioceptive feedback or feedforward processing (body schema) for movement planning and execution, due to altered afferent input from the neck. SCNP participants may thus rely more on visual feedback, to accommodate for impaired cerebellar processing. This quasi-experimental study sought to determine whether upper limb kinematics and oculomotor processes were impacted in those with SCNP. 25 SCNP and 25 control participants who were right-hand dominant performed bidirectional aiming movements using two different weighted styli (light or heavy) while wearing an eye-tracking device. Those with SCNP had a greater time to and time after peak velocity, which corresponded with a longer upper limb movement and reaction time, seen as greater constant error, less undershoot in the upwards direction and greater undershoot in the downwards direction compared to controls. SCNP participants also showed a trend towards a quicker ocular reaction and movement time compared to controls, while the movement distance was fairly similar between groups. This study indicates that SCNP alters aiming performances, with greater reliance on visual feedback, likely due to altered proprioceptive input leading to altered cerebellar processing.

Development of the Sensory-Motor Dysfunction Questionnaire and Pilot Reliability Testing

Both chronic and recurrent spinal pain alter sensorimotor integration (SMI), which is demonstrated using complex neurophysiological techniques. Currently, there is no patient-reported outcome measure that documents and/or assesses SMI in populations with spinal problems. The purpose of this study was to develop the Sensory-Motor Dysfunction Questionnaire (SMD-Q) and assess its test-retest reliability and internal consistency in individuals with recurrent spinal pain. The SMD-Q was developed based on the existing literature on motor control disturbances associated with disordered SMI. The initial SMD-Q drafts underwent review by two separate panels of subject matter experts and a focus group with subclinical spine pain. Their suggestions were incorporated into the questionnaire prior to reliability testing. The questionnaire was administered twice at a seven-day interval using QualtricsTM. A total of 20 participants (14 females and 6 males; 20.95 ± 2.46 years of age) completed the study. Quadratic weighted kappa (Kw) was used to assess test-retest reliability and Cronbach's alpha (α) was used to assess internal consistency. Four items had a Kw < 0.40, seven had a 0.40 < Kw < 0.75, and one had a Kw > 0.75 (excellent agreement), with excellent internal consistency (α > 0.90). The pilot SMD-Q appears to reliably measure altered SMI, suggesting that revisions and testing with a larger sample are worth pursuing.

Validity and reliability of the Balance Error Score System (BESS) Thai version in patients with chronic non-specific neck pain

BACKGROUND

Neck pain has been found to affect the somatosensory system, which can lead to impaired balance control. To assess the balance of patients with neck pain and other conditions, the balance error scoring system (BESS) is commonly used as a static balance measurement tool. However, this tool is seldom used in Thailand due to its English language format.

OBJECTIVE

To translate and determine the content, convergent validity, and reliability of a Thai version of the BESS tool.

MATERIAL AND METHODS

A process of cross-cultural adaptation was utilized to translate BESS into a Thai version, called BESS-TH. To assess content validity, five physical therapy lecturers specializing in the musculoskeletal field used BESS to measure balance in participants with neck pain. For the convergent validity process, 130 patients diagnosed with chronic non-specific neck pain (CNSNP) were randomly assessed using four static balance tests (BESS, Single-leg balance test (SLBT), Romberg test, and Tandem stance test). For reliability, two assessors with varying years of work experience independently assessed videos of the participants twice using the BESS-TH, with a minimum 7-day interval between assessments.

RESULTS

The BESS-TH used to assess balance of patients with neck pain demonstrated acceptable content validity (index of item objective congruence (IOC) = 0.87). The Spearman's Rank Correlation Coefficient was calculated between the BESS-TH and three other measures: the SLBT with eyes open and eyes closed, the Romberg test with eyes open and eyes closed, and the Tandem stance test with eyes open and Tandem stance test with eyes closed. The values obtained were as follows: -0.672, -0.712, -0.367, -0.529, -0.570, and -0.738, respectively. The inter-rater and intra-rater reliability were 0.922 (95% CI = 0.864-0.956) and 0.971 (95% CI = 0.950-0.983), respectively. Minimum detectable change (MDC) for the total BESS score of inter-rater and intra-rater reliability were 7.16 and 4.34 points, respectively.

CONCLUSION

The BESS-Thai version was acceptable, reliable, and valid for evaluating balance performance in patients with CNSNP. This tool can be used and applied to clinically evaluate postural control in Thailand.

The reliability and validity of a novel wearable inertial sensor to measure the cervical proprioception

BACKGROUND

Proprioceptive function assessment is crucial in clinical practice for patients with chronic non-specific neck pain (CNNP) as it is a major issue affecting their condition.

PURPOSE

To verify the reliability and validity of baiobit sensor in measuring the neck proprioceptive function of CNNP patients.

METHODS

Fifty-three CNNP patients were recruited (36 females, 17 males; age range 21-60 years) and were assessed for cervical joint position error by two blinded raters using the Baiobit sensor and laser pointer devices. The second measurement was conducted by the same rater 48 h later. Intra and inter-rater reliability of the Baiobit sensor was evaluated using the intra-class correlation coefficient (ICC), while the validity of the Baiobit sensor was established using the Spearman correlation coefficient.

RESULTS

The Baiobit sensor demonstrated moderate to excellent intra-rater reliability in flexion, extension, left lateral flexion, right lateral flexion, and right rotation (ICCs=0.71∼0.85, 95 %CIs: 0.50∼0.91), left-rotation shows poor to good intra-rater reliability (ICC=0.56, 95 %CI: 0.25∼0.75). The Baiobit sensor also demonstrated moderate to excellent inter-rater reliability in flexion, extension, left lateral flexion, right lateral flexion, and right rotation (ICCs=0.80∼0.88, 95 %CIs: 0.65∼0.91), left-rotation shows poor to good intra-rater reliability (ICC=0.59, 95 %CI: 0.29∼0.76). Validity analysis showed that the Baiobit sensor had a range of low to high validity (r = 0.46∼0.88) for measuring cervical proprioception function, with lower validity observed in the left flexion direction. The Baiobit showed good absolute reliability with low SEM and MDC90 values (0.35°∼2.42°).

CONCLUSION

The new device could be used as an alternative tool to evaluate neck proprioception.

Cervico-Ocular and Vestibulo-Ocular Reflexes in Subclinical Neck Pain and Healthy Individuals: A Cross-Sectional Study

Alterations in neck sensory input from recurrent neck pain (known as subclinical neck pain (SCNP)) result in disordered sensorimotor integration (SMI). The cervico-ocular (COR) and vestibulo-ocular (VOR) reflexes involve various neural substrates but are coordinated by the cerebellum and reliant upon proprioceptive feedback. Given that proprioception and cerebellar processing are impaired in SCNP, we sought to determine if COR or VOR gain is also altered. COR and VOR were assessed using an eye-tracking device in 20 SCNP (9 M and 11 F; 21.8 (SD = 2.35) years) and 17 control (7 M and 10 F; 22.40 (SD = 3.66) years) participants. COR gain (10 trials): A motorized chair rotated the trunk at a frequency of 0.04 Hz and an amplitude of 5° while participants gazed at a circular target that disappeared after three seconds. VOR gain (30 trials): Rapid bilateral head movements away from a disappearing circular target while eyes fixated on the last observed target. Independent t-tests on COR and VOR gain were performed. SCNP had a significantly larger COR gain (p = 0.006) and smaller VOR gain (p = 0.487) compared to healthy controls. The COR group differences suggest an association between proprioceptive feedback and SMI, indicating COR may be a sensitive marker of altered cerebellar processing.

Widespread Proprioceptive Acuity Impairment in Chronic Back Pain: A Cross-sectional Study

OBJECTIVE

To investigate whether proprioceptive accuracy measured with the Joint Position Sense (JPS) in patients with chronic neck and low back pain is impaired exclusively in affected areas or also in distant areas, not affected by pain.

DESIGN

Cross-sectional study.

SETTING

Interdisciplinary outpatient rehabilitation clinic for back and neck pain.

PARTICIPANTS

Patients with chronic neck pain (n=30), patients with chronic low back pain (n=30), and age- and sex-matched asymptomatic control subjects (n=30; N=90).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Patients and asymptomatic control subjects completed a test procedure for the JPS of the cervical spine, lumbar spine, and ankle in a randomized order. Between group differences were analyzed with the univariate analysis of variance and associations of the JPS with clinical features using the Pearson's correlation coefficient.

RESULTS

Both patients with chronic neck pain (P<.001) and patients with chronic low back pain (P<.01) differed significantly from asymptomatic controls in the JPS of the cervical spine, lumbar spine and ankle joint, regardless of the painful area. No difference was shown between patient groups (P>.05). An association of the JPS with clinical characteristics, however, could not be shown.

CONCLUSION

These results suggest widespread impairment of proprioceptive accuracy in patients with chronic and low back pain and a role for central sensorimotor processes in musculoskeletal pain conditions.

Muscle strength, balance and upper extremity function are not predictors of cervical proprioception in healthy young subjects

Purpose/Aim: The aim of this study is to examine the relationship between cervical proprioception sense and balance, hand grip strength, cervical region muscle strength and upper extremity functionality in healthy young subjects.Methods: A total of 200 people with a mean age of 20.8 ± 1.8 participated in the study. Cervical proprioception sense of the participants was evaluated with Cervical Joint Position Error Test (CJPET), balance with Biodex Stability System, hand grip strength with hand dynamometer, and upper extremity functionality with Perdue Pegboard test. The relationship of variables with cervical proprioception was evaluated with Pearson Correlation analysis.Results: According to this study results, there was no significant relationship between CJPET (extension, left rotation, right rotation) and sub-parameters of dynamic balance (anteroposterior, mediolateral, overall), cervical muscle strength and hand grip strength (p > 0.05). There was a significant correlation between CJPET flexion and static balance variables (p < 0.05).Conclusion: According to this study, there is no relationship between cervical proprioception and balance, hand grip muscle strength, cervical region muscle strength and upper extremity functionality in healthy young subjects.

Prevalence of Static Balance Impairment and Associated Factors of University Student Smartphone Users with Subclinical Neck Pain: Cross-Sectional Study

The aim of this study was to assess the prevalence of static balance impairment in university student smartphone users with subclinical neck pain and identify the associated risk factors. Because of rapid and widespread smartphones use, and the subsequent effect on neck pain in university students, it is essential to determine the prevalence of balance impairment and associated factors in this population. Simple random sampling was completed among eighty-one participants in this cross-sectional study. A self-reported questionnaire, fitted precisely for smartphone users, was used prior to clinical assessment by the Balance Error Scoring System. Both simple and multiple logistic regressions were used to analyze the prevalence of static balance impairment and associated factors. The prevalence of static balance impairment in university student smartphone users with subclinical neck pain was 74.07% (95% CI: 64.32 to 83.82). The significant risk factors were "daily smartphone use ≥ 4 h'' (AOR: 19.24 (95% CI 4.72 to 78.48) p = 0.000), "≥4 years of smartphone use" (AOR: 5.01 (95% CI 1.12 to 22.38) p = 0.035), and "≥7 neck disability index score'' (AOR: 12.91 (95% CI 2.24 to 74.45) p = 0.004). There was a high prevalence of static balance impairment in university smartphone users with subclinical neck pain. University student smartphone users with subclinical neck pain who met at least one of the risk factors should realize their static balance impairment.

Physical Performance Tests in Adult Neck Pain Patients with and without Clinical Myelopathic Signs: A Matched Case-Control Study

Patients with neck pain may experience cervical myelopathy, this may be detected by clinical myelopathic signs, although they did not have any symptom of myelopathy, except having neck pain. Decreasing physical performance is one symptom of cervical myelopathy that can lead to reduced quality of life in the elderly, however, in adult neck pain with clinical myelopathic signs have not been evaluated. Therefore, this research aimed to compare physical performance in two groups of adult patients with neck pain: those with and without clinical myelopathic signs. A total of 52 participants, gender, age, and body mass index (BMI) matched were allocated into 2 groups of 26 subjects with neck pain, those with, and without, clinical myelopathic signs. The grip and release test, nine-hole peg test, ten second step test and foot-tapping test were evaluated. The group of neck pain participants with clinical myelopathic signs exhibited greater impairment in all the tests than the group without clinical myelopathic signs (p < 0.001). Effect sizes (Cohen’s d) were grip and release test: 2.031, nine-hole peg test: 1.143, ten second step test: 1.329, and foot-tapping test: 0.798. Neck pain participants with clinical myelopathic signs demonstrated reduced physical performance. Physical performance tests may need to assessed in adult patients with neck pain who had clinical myelopathic signs.

Interoceptive accuracy and bias in somatic symptom disorder, illness anxiety disorder, and functional syndromes: A systematic review and meta-analysis

Somatic symptom disorder, illness anxiety disorder, and functional syndromes are characterized by burdensome preoccupation with somatic symptoms. Etiological models propose either increased interoceptive accuracy through hypervigilance to the body, or decreased and biased interoception through top-down predictions about sensory events. This systematic review and meta-analysis summarizes findings of 68 studies examining interoceptive accuracy and 8 studies examining response biases in clinical or non-clinical groups. Analyses yielded a medium population effect size for decreased interoceptive accuracy in functional syndromes, but no observable effect in somatic symptom disorder and illness anxiety disorder. The overall effect size was highly heterogeneous. Regarding response bias, there was a small significant effect in somatic symptom disorder and illness anxiety disorder. Our findings strengthen the notion of top-down factors that result in biased rather than accurate perception of body signals in somatic symptom disorder and illness anxiety disorder.

Influence of Neck Pain, Cervical Extensor Muscle Fatigue, and Manual Therapy on Wrist Proprioception

OBJECTIVE

The purpose of this study was to examine the effects of submaximal isometric neck muscle fatigue and manual therapy on wrist joint position sense (JPS) within healthy individuals and individuals with subclinical neck pain (SCNP).

METHODS

Twelve healthy participants and 12 participants with SCNP were recruited. Each group completed 2 sessions, with 48 hours between sessions. On day 1, both groups performed 2 wrist JPS tests using a robotic device. The tests were separated by a submaximal isometric fatigue protocol for the cervical extensor muscles (CEM). On day 2, both groups performed a wrist JPS test, followed by a cervical treatment consisting of manual therapy (SCNP) or neck rest (20 minutes, control group) and another wrist JPS test. Joint position sense was measured as the participant's ability to recreate a previously presented wrist angle. Each wrist JPS test included 12 targets, 6 into wrist flexion and 6 into wrist extension. Kinematic data from the robot established absolute, variability, and constant error.

RESULTS

Absolute error significantly decreased (P = .01) from baseline to post-fatigue in the SCNP group (baseline = 4.48 ± 1.58°; post-fatigue = 3.90 ± 1.45°) and increased in the control group (baseline = 3.12 ± 0.98°; post-fatigue = 3.81 ± 0.90°). The single session of manual cervical treatment significantly decreased absolute error in participants with SCNP (P = .004).

CONCLUSION

This study demonstrated that neck pain or fatigue can lead to altered afferent input to the central nervous system and can affect wrist JPS. Our findings demonstrate that acute wrist proprioception may be improved in individuals with SCNP by a single cervical manual therapy session.

Comparison and correlation of cervical proprioception and muscle endurance in general joint hypermobility participants with and without non-specific neck pain-a cross-sectional study

Background

Cervical proprioception and muscle endurance are essential for maintaining cervical functional joint stability. Proprioception and muscle endurance may be impaired in those with general joint hypermobility (GJH). Examining these aspects is crucial. This study's aims are to (1) compare the cervical joint position error (JPE) and muscle endurance holding capacities in GJH individuals with and without non-specific neck pain (NSNP) (2) to assess the relationship between hypermobility Beighton scores, cervical JPE's, and muscle endurance in GJH individuals with and without NSNP.

Methods

In this cross-sectional comparative study, 33 GJH participants with NSNP (mean age 21.7 ± 1.8 years) and 35 asymptomatic participants GJH (mean age 22.42 ± 1.7 years) participated. Beighton's score of ≥4 of 9 tests was used as criteria to diagnose GJH. Cervical JPEs were estimated in degrees using a cervical range of motion device, and muscle endurance (flexor and extensor) were estimated in seconds using a stopwatch.

Results

GJH participants with NSNP showed significantly larger cervical JPEs (p < 0.001) and decreased muscle endurance holding times (p < 0.001) compared to asymptomatic participants. Beighton hypermobility scores showed a significant moderate positive correlation with cervical JPEs (flexion: r = 0.43, p = 0.013), left rotation: r = 0.47, p = 0.005, right rotation: r = 0.57, p = 0.001) in NSNP individuals. Also, Beighton hypermobility scores showed a moderate negative correlation with muscle endurance in NSNP (flexor muscles: r = -0.40, p = 0.020, extensor muscles: r = -0.41, p = 0.020, and asymptomatic individuals (flexor muscles: -0.34, p = 0.045, extensor muscles: r = -0.45, p = 0.007).

Conclusion

GJH individuals with NSNP showed increased cervical JPEs and reduced muscle endurance compared to asymptomatic. Individuals with GJH with higher Beighton scores demonstrated increased cervical JPEs and reduced neck muscle endurance holding ability. In clinical practice, therapists should be aware of these findings, incorporate proprioceptive and muscle endurance assessments, and formulate rehabilitation strategies for NSNP individuals with GJM.

The Effects of Spinal Manipulation on Motor Unit Behavior

Over recent years, a growing body of research has highlighted the neural plastic effects of spinal manipulation on the central nervous system. Recently, it has been shown that spinal manipulation improved outcomes, such as maximum voluntary force and limb joint position sense, reflecting improved sensorimotor integration and processing. This study aimed to further evaluate how spinal manipulation can alter neuromuscular activity. High density electromyography (HD sEMG) signals from the tibialis anterior were recorded and decomposed in order to study motor unit changes in 14 subjects following spinal manipulation or a passive movement control session in a crossover study design. Participants were asked to produce ankle dorsiflexion at two force levels, 5% and 10% of maximum voluntary contraction (MVC), following two different patterns of force production (“ramp” and “ramp and maintain”). A significant decrease in the conduction velocity (p = 0.01) was observed during the “ramp and maintain” condition at 5% MVC after spinal manipulation. A decrease in conduction velocity suggests that spinal manipulation alters motor unit recruitment patterns with an increased recruitment of lower threshold, lower twitch torque motor units.

Cervical Proprioception Impairment in Neck Pain-Pathophysiology, Clinical Evaluation, and Management: A Narrative Review

Neck pain is very common, but most of the causes are unknown, making diagnosis and treatment extremely challenging. Current studies have found that one of the main problems in patients with neck pain is the impairment of cervical proprioception, which subsequently leads to cervical sensorimotor control disturbances. Cervical spine has a very delicate proprioceptive system that plays a crucial role in controlling posture and balance. Cervical proprioceptive impairment in neck pain occurs through a variety of mechanisms. Experimental neck muscle pain induced by injection of hypertonic saline results in inhibition of the activation of painful muscle; chronic neck pain causes structural and functional impairment of cervical muscles; excessive activation of mechanoreceptors in degenerative cervical discs and facet joints produces a large number of erroneous sensory signals. Clinical examinations to assess the link between structural pathology and neck pain have been unsuccessful, opening the way for the development of function-based tests. To date, eight neck sensorimotor control tests have been reported to evaluate patients with chronic neck pain. Although some tests may involve different subsystems (such as oculomotor system and vestibular system), all tests measure sensorimotor control in the neck, and the most commonly used is cervical joint position error (JPE) test. Current studies support the effectiveness of exercises targeting different aspects of sensorimotor function, in particular retraining aimed at improving cervical proprioception and muscle coordination. Based on the available evidence, it is recommended that patients with neck pain should be assessed and managed for cervical proprioceptive impairment and sensorimotor control disturbances.

Influence of Forward Head Posture on Cervicocephalic Kinesthesia and Electromyographic Activity of Neck Musculature in Asymptomatic Individuals

OBJECTIVE

The purpose of this study was to compare cervicocephalic kinesthesia and electromyographic (EMG) activity of neck muscles-upper trapezius (UT) and sternocleidomastoid (SCM)-between individuals with and without forward head posture (FHP) and to examine the correlation between cervicocephalic kinesthesia and craniovertebral angle (CVA).

METHODS

Twenty-two asymptomatic individuals with FHP and 22 without FHP were recruited for the present study. Craniovertebral angle was measured, and those with CVA ≤53° were assigned to the FHP group, whereas those with CVA >53° were assigned to the control group. Thereafter, cervicocephalic kinesthesia and EMG activity of the neck muscles were assessed. Cervicocephalic kinesthesia was measured using a head repositioning accuracy test for all cervical spine motions. EMG activity of the UT and SCM muscles was recorded at rest and during activity.

RESULTS

Position-sense error values were found to be significantly greater for all directions-ie, flexion, extension, side flexion, and rotation-in participants with FHP than those without (P < .05). EMG activity of the UT and SCM muscles was found to be significantly raised both at rest and during activity in individuals with FHP relative to the non-FHP group (P < .05). Position-sense error values showed a significant inverse correlation with CVA (P < .05).

CONCLUSION

Findings of the present study suggest that cervicocephalic kinesthesia and activation patterns of the neck muscles may be significantly altered in individuals with FHP. Also, cervicocephalic kinesthesia is significantly associated with the severity of FHP.

Slower reaction and response times and impaired hand-eye coordination in individuals with neck pain

BACKGROUND

Neck pain is associated with sensorimotor dysfunction. Research is sparse of the effect of neck pain on reaction and response times and hand-eye coordination.

OBJECTIVES

To investigate hand and foot reaction and response times and hand-eye coordination in individuals with neck pain and to determine any relationships with clinical features of neck pain.

METHODS

Sixty individuals with neck pain and 60 controls of similar age and gender were recruited. Tests of simple reaction and response time were measured on the dominant hand and foot. Hand-eye coordination was measured by tracing a variety of coordination patterns with different levels of difficulty. Clinical features measured were intensity and duration of pain, and neck disability.

RESULTS

Hand and foot reaction and response times were significantly slower in the neck pain group compared to controls (all p < 0.001). The neck pain group took longer to trace the hand-eye coordination task at the hardest level (p = 0.03). Neck disability scores correlated with hand reaction time (r = 0.4, p = 0.005) and time taken in hand-eye coordination tasks (r = 0.2 for all levels, p < 0.05). Reaction and response times were correlated with time taken in the hand-eye coordination test (r = 0.2-0.4, p < 0.01).

CONCLUSIONS

Individuals with neck pain had slower hand and foot reaction and response times and impaired hand-eye coordination, suggesting deficits in sensorimotor function. Training speed, as a function of acuity, and hand-eye coordination might be considered in clinical assessment. Further research is needed to identify potential underlying mechanisms of the slower and less well coordinated movement.

Upper cervical spine dysfunction and dizziness

Although various causes of dizziness have been identified, many patients suffer from dizziness of unknown etiology and continue to visit hospitals to resolve their symptoms. Problems that occur in the ligaments or muscles of the upper cervical spine can cause confusion in proprioception. These changes can convey misinformation to the vestibular nucleus, resulting in abnormal reactions that can lead to cervicogenic dizziness (CGD). Though CGD remains controversial, it should be considered while diagnosing patients with dizziness. Understanding CGD can help create treatment strategies for them. This article suggested a relationship between the structure and function of the upper cervical spine and dizziness, and presented evaluations and treatments for the same.

Joint position error after neck protraction-retraction movements in healthy office workers: a cross-sectional study

Since the upper cervical spine (UCS) has been regarded to be distinct from the lower cervical spine (LCS), joint position error (JPE) needs to be tested separately for both regions. The purpose of this study was to investigate the JPE after cervical protraction/retraction movements, involving opposite movements of extension and flexion for the UCS and LCS. These movements are frequently performed during office work. Cervical JPEs were tracked in thirty healthy office workers while performing four tests of cervical pro-retraction movements with variations in vision and movement direction, and assessed using the Kinect head tracker (Microsoft Corp), placed in front of each participant. The JPE was expressed in constant (CE), absolute (AE) and variable errors (VE). Multilevel linear models evaluated main and interaction effects of vision, movement direction, cervical region and sex. Slightly larger JPEs have been found in the UCS. Vision showed no effect on any outcome variable. No effect exceeded typical measurement errors reported for the Kinect head tracker. This study showed, that JPEs after pro-retraction movements of the head and neck may differ for UCS and LCS. The differences were small and not beyond measurement error reported for the Kinect.

Association of Subclinical Neck Pain With Altered Multisensory Integration at Baseline and 4-Week Follow-up Relative to Asymptomatic Controls

OBJECTIVE

The purpose of this study was to test whether people with subclinical neck pain (SCNP) had altered visual, auditory, and multisensory response times, and whether these findings were consistent over time.

METHODS

Twenty-five volunteers (12 SCNP and 13 asymptomatic controls) were recruited from a Canadian university student population. A 2-alternative forced-choice discrimination task with multisensory redundancy was used to measure response times to the presentation of visual (color filled circles), auditory (verbalization of the color words, eg, red or blue), and multisensory (simultaneous audiovisual) stimuli at baseline and 4 weeks later.

RESULTS

The SCNP group was slower at both visual and multisensory tasks (P = .046, P = .020, respectively), with no change over 4 weeks. Auditory response times improved slightly but significantly after 4 weeks (P = .050) with no group difference.

CONCLUSIONS

This is the first study to report that people with SCNP have slower visual and multisensory response times than asymptomatic individuals. These differences persist over 4 weeks, suggesting that the multisensory technique is reliable and that these differences in the SCNP group do not improve on their own in the absence of treatment.

Cervical proprioception and its relationship with neck pain intensity in subjects with cervical spondylosis

Background

Cervical proprioception is critical in the maintenance of posture and movements, so its assessment in different cervical conditions has gained importance in recent clinical practice. Studies reporting this assessment in subjects with cervical spondylosis (CS) have not previously been investigated. The goals of the study are (1) comparison of joint position error (JPE) in subjects with CS to healthy control group. (2) Correlation of neck pain intensity to cervical proprioception in patients with CS.

Methods

In a Cross-sectional study, 132 subjects with CS and 132 healthy age-matched control subjects were evaluated for cervical JPE with the cervical range of motion device. The subjects were blindfolded and repositioned their heads to a target position, which was determined by the examiner previously and their repositioning accuracy (absolute error in degrees) was measured in the frontal (flexion and extension) and transverse planes (left rotation and right rotation). The CS subjects resting neck pain intensity was assessed using visual analog scale (VAS).

Results

CS subjects showed statistically significantly larger JPEs compared to healthy control subjects in all the directions tested (flexion - 95% CI = 2.38–3.55, p < 0.001, extension - 95% CI =3.26–4.33, p < 0.001, left rotation - 95% CI = 2.64 - 3.83, p < 0.001, right rotation − 95% CI = 3.77–4.76, p < 0.001). The mean JPE errors in the CS group ranged from 6.27° to 8.28° and in the control group ranged from 2.36° to 4.48°. Pearson’s correlation coefficient showed a significant and positive relationship between neck pain intensity and cervical proprioception (p ≤ 0.001).

Conclusions

Proprioception is impaired in subjects with CS when compared to healthy control group. Higher pain intensity was associated with greater cervical JPE in patients with CS.

Electronic measures of movement impairment, repositioning, and posture in people with and without neck pain-a systematic review

BACKGROUND

Neck pain is a major public health problem. Our objective was to describe differences in measures of movement and posture between people with and without neck pain.

METHODS

PubMed and Embase were searched before 15 February 2019 for studies comparing people with neck pain with controls using electronic measurements of neck movement and/or posture. Data were extracted on participants, device, test methods, active range of motion (RoM) and quality of motion, joint positioning sense, and posture. Study quality was assessed using the quality assessment of studies of diagnostic accuracy included in systematic reviews (QUADAS) and Guidelines for Reporting Reliability and Agreement Studies (GRRAS) guidelines.

RESULTS

Thirty-six studies were included: 24 studies included measurement of active RoM, 15 quality of motion, 12 joint positioning sense, and 5 cervical spine posture. Measurements and test methods were heterogeneous. The reporting of study populations and methods were poor, whereas devices and statistics were well described. All studies on RoM showed reduced active RoM in people with neck pain when compared with controls, 5 of 10 studies reported reduced movement speed for people with neck pain, and 5 of 9 studies reported significantly greater joint positioning error for people with neck pain compared with controls. Due to heterogeneous test parameters and methods, no conclusion regarding differences in conjunct motion, tracking a motion pattern, and measures of posture could be drawn.

CONCLUSIONS

People with neck pain appear to have reduced active RoM, movement speed, and head repositioning accuracy when compared with controls. However, quality of reviewed studies was low and better descriptions of participants and methods are required before firm conclusions can be drawn.

Comparative joint position error in patients with non-specific neck disorders and asymptomatic age-matched individuals

Background

Neck pain is a common complaint worldwide and ranked seventh in 2010 as the cause of ‘years lived with disability’ in Ghana. Proprioceptive dysfunction, measured by joint position error (JPE) tests, indicates an association with neck pain frequency, dizziness and balance problems in patients.

Objectives

To examine proprioceptive deficits of the neck using a laser pointer attached to the head.

Methods

Twenty patients within the age group 21–60 years, with at least five points on the neck disability index (NDI), and 20 age- and sex-matched controls with less than five points on the NDI were recruited for this study. The JPE was determined wearing a headlight laser pointer directed towards a Cartesian coordinate system adjusted to x/y = 0/0, placed on a wall after returning from left and right rotation, flexion and extension. From starting in an upright sitting position, facing the Cartesian coordinate system, each participant performed five repetitions for each movement direction. The mean of five repetitions for each movement direction was calculated as absolute error (AE), constant error (CE) and variable error (VE).

Results

Control participants showed larger JPE values for nearly all AE, CE and VE. After repositioning from flexion controls showed an approximately 0.6 ° larger median JPE, and the opposite for extension, with median differences between 1 ° and 2 °.

Conclusion

The results of this study do not reveal any meaningful differences between patients with mild disabled neck movement compared with controls.

Clinical implications

Joint position error testing does not seem useful for patients with mild neck disability.

Increased Voluntary Activation of the Elbow Flexors Following a Single Session of Spinal Manipulation in a Subclinical Neck Pain Population

To investigate the effects of a single session of spinal manipulation (SM) on voluntary activation of the elbow flexors in participants with subclinical neck pain using an interpolated twitch technique with transcranial magnetic stimulation (TMS), eighteen volunteers with subclinical neck pain participated in this randomized crossover trial. TMS was delivered during elbow flexion contractions at 50%, 75% and 100% of maximum voluntary contraction (MVC) before and after SM or control intervention. The amplitude of the superimposed twitches evoked during voluntary contractions was recorded and voluntary activation was calculated using a regression analysis. Dependent variables were analyzed with two-way (intervention × time) repeated measures ANOVAs. Significant intervention effects for SM compared to passive movement control were observed for elbow flexion MVC (p = 0.04), the amplitude of superimposed twitch (p = 0.04), and voluntary activation of elbow flexors (p =0.03). Significant within-group post-intervention changes were observed for the superimposed twitch (mean group decrease of 20.9%, p < 0.01) and voluntary activation (mean group increase of 3.0%, p < 0.01) following SM. No other significant within-group changes were observed. Voluntary activation of the elbow flexors increased immediately after one session of spinal manipulation in participants with subclinical neck pain. A decrease in the amplitude of superimposed twitch during elbow flexion MVC following spinal manipulation suggests a facilitation of motor cortical output.

Asymmetric Thickness of Oblique Capitis Inferior and Cervical Kinesthesia in Patients With Unilateral Cervicogenic Headache

OBJECTIVE

The purpose of this study was to compare the thickness of the oblique cervical inferior (OCI) and the error of the head reposition test between the painful and nonpainful sides of patients with cervicogenic headache (CeH) and between the patients and the asymptomatic group.

METHODS

Thirteen patients (24.5 ± 4.8 years) and 14 asymptomatic participants (23.9 ± 2.7 years) were included. The head reposition test was recorded by a 3-dimensional motion analysis system. The thickness of the OCI was recorded by ultrasonography. The measured outcomes were compared between the painful and nonpainful sides and with the asymptomatic participants.

RESULTS

The thickness of the OCI in the rest condition on the painful side (9.92 ± 2.31 mm) was smaller than that of the nonpainful side (10.56 ± 2.24 mm). The constant error of the head-to-target test toward the nonpainful side was smaller in the patients with CeH (-1.6 ± 4.3°) than in the asymptomatic group (3.3 ± 3.7°, P = 0.005).

CONCLUSION

Asymmetric OCI and cervical proprioception were demonstrated in patients with CeH.

Asymmetry of neck motion and activation of the cervical paraspinal muscles during prone neck extension in subjects with unilateral posterior neck pain

BACKGROUND

Although unilateral posterior neck pain (UPNP) is more prevalent than central neck pain, little is known about how UPNP affects neck motion and the muscle activation pattern during prone neck extension.

OBJECTIVE

To investigate whether deviation in neck motion and asymmetry of activation of the bilateral cervical paraspinal muscles occur during prone neck extension in subjects with UPNP compared to subjects without UPNP.

METHODS

This study recruited 20 subjects with UPNP and 20 age- and sex-matched control subjects without such pain. Neck motion and muscle onset time during prone neck extension were measured using a three-dimensional motion-analysis system and surface electromyography.

RESULTS

The deviation during prone neck extension was greater in the UPNP group than in the controls (p < 0.05). Compared with the controls, cervical extensor muscle activation in the UPNP group was significantly delayed on the painful side during prone neck extension (p < 0.05).

CONCLUSIONS

Subjects with UPNP showed greater asymmetry of neck motion and muscle activation during prone neck extension compared with the controls. This suggests that UPNP has specific effects on neck motion asymmetry and the functions of the cervical extensors, triggering a need for specific evaluation and exercises in the management of patients with UPNP.

Subclinical recurrent neck pain and its treatment impacts motor training-induced plasticity of the cerebellum and motor cortex

The cerebellum processes pain inputs and is important for motor learning. Yet, how the cerebellum interacts with the motor cortex in individuals with recurrent pain is not clear. Functional connectivity between the cerebellum and motor cortex can be measured by a twin coil transcranial magnetic stimulation technique in which stimulation is applied to the cerebellum prior to stimulation over the motor cortex, which inhibits motor evoked potentials (MEPs) produced by motor cortex stimulation alone, called cerebellar inhibition (CBI). Healthy individuals without pain have been shown to demonstrate reduced CBI following motor acquisition. We hypothesized that CBI would not reduce to the same extent in those with mild-recurrent neck pain following the same motor acquisition task. We further hypothesized that a common treatment for neck pain (spinal manipulation) would restore reduced CBI following motor acquisition. Motor acquisition involved typing an eight-letter sequence of the letters Z,P,D,F with the right index finger. Twenty-seven neck pain participants received spinal manipulation (14 participants, 18–27 years) or sham control (13 participants, 19–24 years). Twelve healthy controls (20–27 years) also participated. Participants had CBI measured; they completed manipulation or sham control followed by motor acquisition; and then had CBI re-measured. Following motor acquisition, neck pain sham controls remained inhibited (58 ± 33% of test MEP) vs. healthy controls who disinhibited (98 ± 49% of test MEP, P<0.001), while the spinal manipulation group facilitated (146 ± 95% of test MEP, P<0.001). Greater inhibition in neck pain sham vs. healthy control groups suggests that neck pain may change cerebellar-motor cortex interaction. The change to facilitation suggests that spinal manipulation may reverse inhibitory effects of neck pain.

Cervical Proprioception in a Young Population Who Spend Long Periods on Mobile Devices: A 2-Group Comparative Observational Study

OBJECTIVES

The purpose of this study was to evaluate if young people with insidious-onset neck pain who spend long periods on mobile electronic devices (known as "text neck") have impaired cervical proprioception and if this is related to time on devices.

METHODS

A 2-group comparative observational study was conducted at an Australian university. Twenty-two participants with text neck and 22 asymptomatic controls, all of whom were 18 to 35 years old and spent ≥4 hours per day on unsupported electronic devices, were assessed using the head repositioning accuracy (HRA) test. Differences between groups were calculated using independent sample t-tests, and correlations between neck pain intensity, time on devices, and HRA test were performed using Pearson's bivariate analysis.

RESULTS

During cervical flexion, those with text neck (n = 22, mean age ± standard deviation [SD]: 21 ± 4 years, 59% female) had a 3.9° (SD: 1.4°) repositioning error, and the control group (n = 22, 20 ± 1 years, 68% female) had a 2.9° (SD: 1.2°) error. The mean difference was 1° (95% confidence interval: 0-2, P = .02). For other cervical movements, there was no difference between groups. There was a moderately significant correlation (P ≤ .05) between time spent on electronic devices and cervical pain intensity and between cervical pain intensity and HRA during flexion.

CONCLUSION

The participants with text neck had a greater proprioceptive error during cervical flexion compared with controls. This could be related to neck pain and time spent on electronic devices.

The effects of subclinical neck pain on sensorimotor integration following a complex motor pursuit task

Recurrent subclinical neck pain (SCNP) may be associated with neural plastic changes in sensory processing and sensorimotor integration (SMI); however, its impact on motor learning has not been investigated. The aim of this study was to investigate whether SCNP alters neural markers of SMI during a complex motor acquisition task as compared to a healthy control group. Peripheral N9, spinal N13, brainstem N18, and cortical N20, P25, N24 and N30 early somatosensory evoked potentials (SEPs) were recorded following median nerve stimulation for 24 participants (12 control and 12 SCNP) before and after a 10-min tracing motor task intervention. Retention was assessed 24-48 h later. Significant amplitude differences were observed for both N18 and N24 SEP waveforms between groups, indicating there may be a difference in SMI due to altered afferent input as a result of SCNP. Accuracy increased significantly for both groups post-motor training; however, at retention only the control group showed an additional increase in accuracy. Both N18 and N24 SEP peaks are linked with cerebellar pathways, suggesting that SCNP impacts these connections. Significant correlations between these peaks and performance data were also seen. The differential changes in neurophysiological markers of SMI seen in SCNP suggest that SEPs have the potential to be used as an early screening tool for those at risk of having maladaptive neural plastic changes in response to motor training as a result of SCNP.

Disturbed cervical proprioception affects perception of spatial orientation while in motion

The proprioceptive, visual and vestibular sensory systems interact to maintain dynamic stability during movement. The relative importance and interplay between these sensory systems is still not fully understood. Increased knowledge about spatial perception and postural orientation would provide better understanding of balance disorders, and their rehabilitation. Displacement of the body in space was recorded in 16 healthy subjects performing a sequence of stepping-in-place tests without any visual or auditory cues. Spatial displacement and orientation in space were determined by calculating two parameters, “Moved distance (sagittal + lateral displacement)” and “Rotation”. During the stepping-in-place tests vibration were applied in a randomized order on four different cervical muscles, and the effects were compared between muscles and to a non-vibration baseline condition. During the tests a forward displacement (“Moved distance”) was found to be the normal behavior, with various degrees of longitudinal rotation (“Rotation”). The moved distance was significantly larger when the vibration was applied on the dorsal muscles (916 mm) relative to on ventral muscles (715 mm) (p = 0.003) and the rate of displacement was significantly larger for dorsal muscles (36.5 mm/s) relative to ventral (28.7 mm/s) vs (p = 0.002). When vibration was applied on the left-sided muscles, 16° rotation to the right was induced (p = 0.005), whereas no significant rotation direction was induced with right-sided vibration (3°). The rate of rotation was significantly larger for vibration applied on ventral muscles (0.44°/s) relative to on dorsal (0.33°/s) (p = 0.019). The results highlight the influence of cervical proprioception on the internal spatial orientation, and subsequent for postural control.

Intra- and inter-rater reliability of neutral head position and target head position tests in patients with and without neck pain

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Neutral head and target head position tests evaluate cervical proprioception.

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Clinics commonly use those position tests, and it is important to test their reliability.

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Intra- and inter-rater reliability was moderate to high for these tests.

Background

Cervical proprioception is a common term used in neck rehabilitation, and it is examined using neutral head position (NHP) and target head position (THP) tests.

Objective

To investigate intra- and inter-rater reliability of the NHP and THP tests in patients with neck pain and in healthy controls.

Methods

The intra-rater (between-day) and inter-rater (within-day) reliability of the NHP and THP tests were assessed in 36 patients with neck pain and 33 healthy subjects. NHP testing was evaluated in cervical extension, while THP testing was evaluated in six directions of cervical motion: cervical flexion, extension, side bending right, side bending left, rotation right, and rotation left.

Results

The intra-rater reliability for the NHP tests had intraclass correlation coefficient (ICC) values of 0.74–0.78 and a standard error of measurement (SEM) of 1.78–1.88; the THP tests had ICC values of 0.70–0.83 and SEM of 1.45–2.45. Likewise, inter-rater reliability for NHP had ICC values of 0.74–0.79 and SEM of 1.79–1.87. For the THP test, the inter-rater reliability had ICC values of 0.62–0.84 and SEM of 1.50–2.23.

Conclusion

Intra- and inter-rater reliability ranged from good to very good agreement both for NHP and for THP tests of cervical proprioception.

Impact of Spinal Manipulation on Cortical Drive to Upper and Lower Limb Muscles

This study investigates whether spinal manipulation leads to changes in motor control by measuring the recruitment pattern of motor units in both an upper and lower limb muscle and to see whether such changes may at least in part occur at the cortical level by recording movement related cortical potential (MRCP) amplitudes. In experiment one, transcranial magnetic stimulation input-output (TMS I/O) curves for an upper limb muscle (abductor pollicus brevis; APB) were recorded, along with F waves before and after either spinal manipulation or a control intervention for the same subjects on two different days. During two separate days, lower limb TMS I/O curves and MRCPs were recorded from tibialis anterior muscle (TA) pre and post spinal manipulation. Dependent measures were compared with repeated measures analysis of variance, with p set at 0.05. Spinal manipulation resulted in a 54.5% ± 93.1% increase in maximum motor evoked potential (MEPmax) for APB and a 44.6% ± 69.6% increase in MEPmax for TA. For the MRCP data following spinal manipulation there were significant difference for amplitude of early bereitschafts-potential (EBP), late bereitschafts potential (LBP) and also for peak negativity (PN). The results of this study show that spinal manipulation leads to changes in cortical excitability, as measured by significantly larger MEPmax for TMS induced input-output curves for both an upper and lower limb muscle, and with larger amplitudes of MRCP component post manipulation. No changes in spinal measures (i.e., F wave amplitudes or persistence) were observed, and no changes were shown following the control condition. These results are consistent with previous findings that have suggested increases in strength following spinal manipulation were due to descending cortical drive and could not be explained by changes at the level of the spinal cord. Spinal manipulation may therefore be indicated for the patients who have lost tonus of their muscle and/or are recovering from muscle degrading dysfunctions such as stroke or orthopaedic operations and/or may also be of interest to sports performers. These findings should be followed up in the relevant populations.

Accuracy of Different Modalities to Record Natural Head Position in 3 Dimensions: A Systematic Review

PURPOSE

Three-dimensional (3D) images are taken with positioning devices to ensure a patient's stability, which, however, place the patient's head into a random orientation. Reorientation of images to the natural head position (NHP) is necessary for appropriate assessment of dentofacial deformities before any surgical planning. The aim of this study was to review the literature systematically to identify and evaluate the various modalities available to record the NHP in 3 dimensions and to compare their accuracy.

MATERIALS AND METHODS

A systematic literature search of the PubMed, Cochrane Library and Embase databases, with no limitations on publication time or language, was performed in July 2015. The search and evaluations of articles were performed in 4 rounds. The methodologies, accuracies, advantages, and limitations of various modalities to record NHP were examined.

RESULTS

Eight articles were included in the final review. Six modalities to record NHP were identified, namely 1) stereophotogrammetry, 2) facial markings along laser lines, 3) clinical photographs and the pose from orthography and scaling with iterations (POSIT) algorithm, 4) digital orientation sensing, 5) handheld 3D camera measuring system, and 6) laser scanning. Digital orientation sensing had good accuracy, with mean angular differences from the reference within 1° (0.07 ± 0.49° and 0.12 ± 0.54°, respectively). Laser scanning was shown to be comparable to digital orientation sensing. The method involving clinical photographs and the POSIT algorithm was reported to have good accuracy, with mean angular differences for pitch, roll, and yaw within 1° (-0.17 ± 0.50°). Stereophotogrammetry was reported to have the highest reliability, with mean angular deviations in pitch, roll, and yaw for active and passive stereophotogrammetric devices within 0.1° (0.004771 ± 0.045645° and 0.007572 ± 0.079088°, respectively).

CONCLUSIONS

This systematic review showed that recording the NHP in 3 dimensions with a digital orientation sensor has good accuracy. Laser scanning was found to have comparable accuracy to digital orientation sensing, but routine clinical use was limited by its high cost and low portability. Stereophotogrammetry and the method using a single clinical photograph and the POSIT algorithm were potential alternatives. Nevertheless, clinical trials are needed to verify their applications in patients. Preferably, digital orientation sensor should be used as a reference for comparison with new proposed methods of recording the NHP in future research.

The reliability of the cervical relocation test on people with and without a history of neck pain

BACKGROUND

Physical therapy intervention is often sought to treat cervical spine conditions and a comprehensive physical therapy examination has been associated with more favourable outcomes. The cervical relocation test (CRT) is one method used to assess joint position sense (PS) integrity of the cervical spine. Previous research has found significant differences in the CRT between symptomatic and asymptomatic subjects. Impaired kinaesthetic awareness in the cervical spine may be associated with degenerative joint disease, chronicity of the complaint and increased susceptibility to re-injury.

PURPOSE

The purpose of this study was to determine the intertester and intratester reliability of cervical relocation using the cervical range of motion instrument (CROM) and an affixed laser (AL) device among subjects with and without a history of neck pain. In addition, it was hypothesised that those individuals with a history of neck pain would have greater difficulty on the CRT.

METHODS

A total of 50 asymptomatic subjects (n = 50) were assigned to two researchers. The CRT was performed for each tester by the subject rotating the cervical spine for three trials to the right and left for the CROM and AL.

RESULTS

The results indicate a significant intertester reliability of the CROM (interclass correlation coefficient (ICC) = 0.717[0.502-0.839]; 0.773[0.595-0.873]) for the subjects in this sample.

CONCLUSION

This study demonstrated that the CROM is a reliable device for measuring cervical relocation between different testers. Future research should investigate if the CRT is predictive of prognosis in patients with cervical pathology.

Manipulation of Dysfunctional Spinal Joints Affects Sensorimotor Integration in the Prefrontal Cortex: A Brain Source Localization Study

Objectives. Studies have shown decreases in N30 somatosensory evoked potential (SEP) peak amplitudes following spinal manipulation (SM) of dysfunctional segments in subclinical pain (SCP) populations. This study sought to verify these findings and to investigate underlying brain sources that may be responsible for such changes. Methods. Nineteen SCP volunteers attended two experimental sessions, SM and control in random order. SEPs from 62-channel EEG cap were recorded following median nerve stimulation (1000 stimuli at 2.3 Hz) before and after either intervention. Peak-to-peak amplitude and latency analysis was completed for different SEPs peak. Dipolar models of underlying brain sources were built by using the brain electrical source analysis. Two-way repeated measures ANOVA was used to assessed differences in N30 amplitudes, dipole locations, and dipole strengths. Results. SM decreased the N30 amplitude by 16.9 ± 31.3% (P = 0.02), while no differences were seen following the control intervention (P = 0.4). Brain source modeling revealed a 4-source model but only the prefrontal source showed reduced activity by 20.2 ± 12.2% (P = 0.03) following SM. Conclusion. A single session of spinal manipulation of dysfunctional segments in subclinical pain patients alters somatosensory processing at the cortical level, particularly within the prefrontal cortex.

Influence of Subclinical Neck Pain on the Ability to Perform a Mental Rotation Task: A 4-Week Longitudinal Study With a Healthy Control Group Comparison

OBJECTIVE

Mental rotation of objects and the frame of reference of those objects are critical for executing correct and skillful movements and are important for object recognition, spatial navigation, and movement planning. The purpose of this longitudinal study was to compare the mental rotation ability of those with subclinical neck pain (SCNP) to healthy controls at baseline and after 4 weeks.

METHODS

Twenty-six volunteers (13 SCNP and 12 healthy controls) were recruited from a university student population. Subclinical neck pain participants had scores of mild to moderate on the Chronic Pain Grade Scale, and controls had minimal or no pain. For the mental rotation task, participants were presented with an object (letter "R") on a computer screen presented randomly in either normal or backwards parity at various orientations (0°, 45°, 90°, 135°, 180°, 225°, 270°, and 315°). Participants indicated the object's parity by pressing "N" for normal or "B" for backwards. Each orientation for normal and backward parities was presented 5 times, and the average response time for all letter presentations was calculated for each participant, at baseline and 4 weeks later.

RESULTS

Both groups had overall improved response times from baseline to 4 weeks. Healthy participants had significantly improved response times compared to SCNP, both at baseline (P < .05) and 4 weeks (P < .05).

CONCLUSIONS

Healthy participants performed better than the SCNP group at both time points. Subclinical neck pain may impair the ability to perform a complex mental rotation task involving cerebellar connections, possibly due to altered body schema.

The effect of manual therapy with augmentative exercises for neck pain: a randomised clinical trial

OBJECTIVES

To compare the effect of manual therapy (MT) and an augmentative exercise programme (AEP) versus MT and general neck range of motion (ROM) on functional outcomes for patients with neck pain. A secondary objective was to examine changes in self-report measures and quantitative sensory testing (QST) following MT and AEP.

METHODS

This was a randomised clinical trial. Seventy-two patients with neck pain were recruited. All patients received a single session of MT. Patients were randomly assigned to MT+AEP or MT+ROM. Clinical self-report outcome measures for disability and pain, and QST measures (pain and vibration thresholds) were collected at baseline, post MT treatment, at ∼48 hours, and at ∼96 hours. Repeated measures ANOVA and MANOVA were used to analyse within and between-group effects for clinical and QST measures.

RESULTS

There were no between-group differences for disability, pain and QST measures. There was, however, a significant difference between groups for Global Rating of Change (GRoC) scores (P = 0.037). Patients in both groups showed improvements in pain, disability and trapezius pressure-pain threshold (PPT) (all P < 0.001).

DISCUSSION

Augmentative exercise programme does not significantly improve disability, pain or QST measures in patients with chronic neck pain although it may enhance their GRoC scores. Over a 96-hour period, patients benefitted from MT plus exercise whether the exercise was general or specific.

Wearing American Football helmets increases cervicocephalic kinaesthetic awareness in "elite" American Football players but not controls

Background

While there have been investigations into the reduced neck injury rate of wearing protective helmets, there is little information on its effects on normal kinaesthetic neck function. This study aims to quantify the kinaesthetic and movement effects of the American football helmet.

Methods

Fifteen British Collegiate American football players (mean age 22.2, SD 1.9; BMI kg.m² 26.3, SD 3.7) were age and size matched to 11 non-American football playing university students (mean age 22.5, SD 3.6; BMI 24.3, SD 3.3 kg.m²). Both groups had their active cervical range of motion and head repositioning accuracy measured during neck flexion/extension using a modified cervical range of motion device and a similarly modified football helmet.

Results

Wearing helmets significantly reduced active cervical range of motion in extension in both groups (P = 0.007 and P = 0.001 Controls and American Footballers respectively). While both groups had similar repositioning when not wearing a helmet (flexion P = 0.99; extension P = 0.52), when wearing helmets, American football players appeared to be more accurate in relation to cervical kinaesthetic repositioning (ANOVA: P = 0.077: flexion effect size =0.84; extension effect size =0.38).

Conclusions

Wearing American football helmets significantly reduces the active cervical range of motion in extension, along with a change in the neutral head position. American footballers have a greater accuracy in repositioning their head from flexion (potentially enhanced proprioception) when wearing a helmet. This finding might allow development of a simple objective test to help discern presence of minor concussive or cervical musculoskeletal injury on or off the field.

Head repositioning accuracy in patients with neck pain and asymptomatic subjects: concurrent validity, influence of motion speed, motion direction and target distance

BACKGROUND

Cervicocephalic kinesthetic deficiencies have been demonstrated in patients with chronic neck pain (NP). On the other hand, authors emphasized the use of different motion speeds for assessing functional impairment of the cervical spine.

PURPOSE

The objectives of this study were (1) to investigate the head repositioning accuracy in NP patients and control subjects and (2) to assess the influence of target distance, motion speed, motion direction and pain.

MATERIALS AND METHODS

Seventy-one subjects (36 healthy subjects and 35 NP patients; age 30-55 years) performed the head repositioning test (HRT) at two different speeds for horizontal and vertical movements and at two different distances. For each condition, six consecutive trials were sampled.

RESULTS

The study showed the validity and reproducibility of the HRT, confirming a dysfunctional threshold of 4.5°. Normative values of head repositioning error up to 3.6° and 7.1° were identified for healthy and NP subjects, respectively. A distance of 180 cm from the target and a natural motion speed increased HRT accuracy. Repositioning after extension movement showed a significantly larger error in both groups. Intensity, duration of pain as well as pain level did not significantly alter head repositioning error.

CONCLUSIONS

The assessment of proprioceptive performance in healthy and NP subjects allowed the validation of the HRT. The HRT is a simple, not expensive and fast test, easily implementable in daily practice to assess and monitor treatment and evolution of proprioceptive cervical deficits.

Changes of postural control and muscle activation pattern in response to external perturbations after neck flexor fatigue in young subjects with and without chronic neck pain

PURPOSE

Previous studies have identified sensorimotor disturbances and greater fatigability of neck muscles in patients with neck pain. The purpose of this study was to investigate the effect of neck pain and neck flexor fatigue on standing balance following postural perturbations.

METHODS

Twenty patients with chronic neck pain (CNP) (24.7±3.6 year-old) and 20 age-matched asymptomatic subjects (22.1±2.2 year-old) were recruited. Subjects stood barefoot on a force plate and experienced backward perturbations before and after neck flexor fatigue. Center of pressure, electromyography of cervical and lumbar muscles, and head/trunk accelerations were recorded. Two-way ANOVA (pain×fatigue) was used for statistical analysis.

RESULTS

CNP group showed larger body sway during quiet standing but not during perturbed standing compared with asymptomatic adults. In both groups, neck flexor fatigue resulted in greater body sway during the quiet standing but smaller body sway during perturbed standing, increased neck muscle activations and decreased lumbar muscle activations, as well as increased time to maximal head acceleration.

CONCLUSIONS

Disturbed balance control was observed in CNP patients during the quiet standing. However, a rigid strategy was used to minimize the postural sway and to protect the head against backward perturbations in both CNP and asymptomatic young adults after neck flexor fatigue. The results facilitate the understanding of how the subjects with chronic neck pain and with neck muscle fatigue deal with the challenging condition. Further studies are needed to verify if such phenomenon could be changed after the intervention of specific flexor muscle retraining and balance control exercises.

Is performance in goal oriented head movements altered in patients with tension type headache?

Background

Head repositioning tasks have been used in different experimental and clinical contexts to quantitatively measure motor control performance. Effects of pain on sensorimotor control have often been described in various musculoskeletal conditions and may provide relevant information with regard to potential mechanisms underlying tension-type headaches. The purpose of the current study was to compare the performance of patients with tension-type headache and healthy participants in a cervical aiming task using the Fitts’ task paradigm.

Methods

Patients with tension-type headache and healthy controls were compared in a cervical aiming task. Participants were asked to move their head as quickly, and precisely as possible to a target under various experimental conditions. Dependent variables included movement time, variable error, constant error and absolute error.

Results

As predicted by Fitts’ law, decreasing target size and increasing head rotation amplitudes yielded longer movement times in both groups. Participants with tension-type headache, when compared to healthy participants showed a significant increase in both constant and absolute errors for each of the four conditions.

Conclusion

Decreased motor performance was observed in participants with tension-type headache, likely due to altered motor control of the neck musculature. Future research is warranted to investigate the clinical aspect related to decrease in motor performance.