Movement coordination and differential kinematics of the cervical and thoracic spines in people with chronic neck pain

Neck Kinematics in Patients With Chronic Mechanical Neck Pain: An Observational Study to Explore the Integration of Multiple Influencing Factors Through a Bayesian Model-Based Approach

The aim of this observational, cross-sectional study is to evaluate potential differences in kinematics, specifically range of motion (ROM) and velocity, during planar cervical movements between patients with non-traumatic chronic neck pain and disability and asymptomatic controls, while accounting for potential influencing variables of age, sex and fear of movement. The influence of pain intensity, neck disability, age, sex or fear of motion on kinematics was analyzed through robust multivariate Bayesian regression models fitted using the brms library in R. Forty-three patients with neck pain (aged 36.70 ± 13.75 years; 10 men and 33 women) and 42 asymptomatic participants (aged 32.74 ± 13.24 years; 25 men and 17 women) completed the study protocol. The presence of neck pain/disability was associated with lower ROM and peak velocity during all planar movements when considering the influence of age, sex or fear of motion, with standardized regression coefficients that had a small effect size (ranged from 0.11 to 0.28) and estimated differences of less than 2.21° in ROM and 25.61°/s in peak velocity. Although patients with chronic mechanical neck pain showed reduced ROM and peak velocity, the small effect sizes and the low estimated differences between groups question the relevance and clinical usefulness of kinematic analysis of planar movements in samples of patients similar to those included in our study. It is probable that there are differences between the groups, but it is insufficient to rely solely on kinematic variables for patient discrimination. This limitation likely arises from the substantial variability in patient kinematics.

Effect of chest wall mobilization on respiratory muscle function in patients with severe chronic obstructive pulmonary disease (COPD): A randomized controlled trial

BACKGROUND

Clinical trials have demonstrated positive correlation between pulmonary function and chest wall expansion in COPD. Decrease in chest wall expansion in patients with COPD compromises rib cage mobility and functional length of respiratory muscles that ultimately jeopardize the efficacy and function of respiratory system.

METHOD

Thirty male adults (mean age: 74.97 ± 6.29) suffered with severe COPD were randomly allocated to either experimental group (chest wall mobilizations) or control group. Both groups received standardized education and walking exercise (twice/week) for 6 weeks. Patients in experimental group received additional chest wall mobilizations that include stretching and joints mobilization. Pulmonary function, respiratory muscle strength, thoracic excursion, cervical and thoracic range of movement were evaluated at baseline, post-program and at 3-month follow-up.

RESULTS

There were significantly greater improvements in respiratory muscle strength, thoracic excursion and thoracic range of movement (p < 0.01) except thoracic flexion. Lower thoracic excursion is strongly associated with increase in maximum inspiratory pressure (β = 13.64, p < 0.001) and maximum expiratory pressure (β = 16.23, p < 0.001). Thoracic range of movement especially extension (p < 0.001) and bilateral rotation (p < 0.01) exhibit a strong relationship with increase in lower thoracic excursion (adjusted R2 = 0.876) as shown in multiple regression analysis.

CONCLUSION

Additional chest wall mobilization in the rehabilitation of patients with COPD is likely to enhance thoracic extension and rotation which increase lower thoracic excursion. This significant improvement in chest expansion capacity allows respiratory muscles to work at an optimal functional length which result in greater respiratory muscle strength in patients with severe COPD.

Perceived pain and disability but not fear of movement are associated with altered cervical kinematics in people with acute neck pain following a whiplash injury

OBJECTIVES

To determine if measures of cervical kinematics are altered in people with acute whiplash associated disorders (WAD) and secondarily, to examine whether kinematic variables are associated with self-reported outcomes.

METHODS

We recruited people with acute WAD within 15 days after a motor vehicle collision and asymptomatic control participants. All participants performed active neck movements at a self-determined velocity. Maximal range of motion (ROM), peak and mean velocity of movement, smoothness of movement, and cervical joint position error were assessed. Moreover, self-reported measures of perceived pain and disability, pain catastrophising, and fear of movement were obtained.

RESULTS

Sixty people participated: 18 with acute WAD (mean age [SD] 38.7 [12.0]) and 42 as asymptomatic controls (mean age [SD] 38.4 [10.2]). Participants with acute WAD showed significantly decreased ROM in all movement directions (p < 0.0001). All participants with acute WAD showed a reduction in the mean and peak velocity of movement in all directions (p < 0.0001) and the number of velocity peaks was significantly higher (i.e., reduced smoothness of movement) in those with acute WAD in all directions (p < 0.0001). Repositioning acuity following cervical rotation was not significantly different between groups. Neck pain-related disability showed the largest number of significant associations with kinematic features, while fear of movement was not associated with measures of cervical kinematics.

CONCLUSIONS

Participants with acute WAD presented with altered cervical kinematics compared to asymptomatic participants. Several measures of cervical kinematics were associated with the level of pain and disability in people with acute WAD but not their fear of movement.

Analysis of time-space variations during dynamic cervical spine motion in cervical spondylosis myelopathy patients

BACKGROUND CONTEXT

Decreased cervical range of motion (ROM) is a common symptom of myelopathy patients. Many previous studies have relied on a variety of experimental approaches for quantifying static cervical range of motion. However, the change rules of time-space variation during dynamic cervical spine motion remains unknown.

PURPOSE

To develop and validate the effectiveness of a novel wearable robot-based sensor system, Analysis of Dynamic Cervical spine Motion (ADCM), in evaluating the dynamic cervical spine motion dysfunction of patients with cervical spondylotic myelopathy (CSM).

STUDY DESIGN/SETTING

A cross-sectional study.

PATIENT SAMPLE

One hundred forty consecutive healthy individuals (70 men and 70 women) and 120 CSM patients (60 men and 60 women) were enrolled in the present study.

OUTCOME MEASURES

The cervical motion process parameters, including the flexion and extension ROM, the flexion and extension time, and the Japanese Orthopedic Association scores (JOA) for cervical spine were measured.

METHODS

Two hundred and sixty consecutive participants were asked to wear ADCM system and then fully flex and extend their neck rapidly and evenly at tolerable maximum speed. The cervical motion process was recorded and converted into waveforms. Relevant waveform parameters were measured and analyzed. The number of complete flexion-extension motions in 10 seconds has been defined as 10s F-E cycles. The Japanese Orthopedics Association (JOA) scores of CSM patients were marked.

RESULTS

CSM patients had a lower number of 10s F-E cycles than healthy subjects. There were significant differences in flexion and extension time and ROM between two groups. The waveforms of myelopathy patients were wider and lower than those in healthy individuals. The average ratio value (defined as F) of wave height to wave width (a+b/c+d) could quantitatively reflect such differences of waveforms. The average F value was correlated with the JOA scores of the cervical motion function (r=0.7538), and F value declined as JOA scores decreased. According to receiver operating characteristic curve analysis, the optimal threshold value of the normal average ratio was more than 34.7.

CONCLUSIONS

ADCM appears to be an objective and quantitative severity assessment tool for confirmed CSM patients by evaluating dynamic cervical spine motion dysfunction.

A novel virtual reality application for autonomous assessment of cervical range of motion: development and reliability study

Background

Neck pain, one of the most common musculoskeletal diseases, affects 222 million people worldwide. The cervical range of motion (CROM) is a tool used to assess the neck's state across three movement axes: flexo-extension, rotation, and lateral flexion. People with neck pain often have a reduced CROM, and they feel pain at the end-range and/or accompany neck movements with compensatory trunk movements. Virtual reality (VR) setups can track the movement of the head and other body parts in order to create the sensation of immersion in the virtual environment. Using this tracking position information, a CROM assessment can be performed using a VR setup that may be carried out autonomously from the user's home. The objectives of this study were to develop a VR experience that could be used to perform a CROM assessment, and to evaluate the intra-rater and inter-rater reliability of the CROM measures guided by this VR experience. To the best of our knowledge, a study of this type has not been carried out before.

Materials & Methods

A total of 30 asymptomatic adults were assessed using a VR device (HTC Vive Pro Eye™). Two raters provided support with the VR setup, and the participants were guided by the VR experience as they performed the movements. Each rater tested each subject twice, in random order. In addition to a head-mounted display (HMD), a tracker located on the subject's back was used to measure trunk compensatory movements. The CROM was estimated using only the HMD position and this measurement was corrected using the tracker data. The mean and standard deviation were calculated to characterize the CROM. To evaluate the reliability, the interclass correlation coefficients (ICC) were calculated for intra-rater and inter-rater analysis. The standard error of measurement and minimum detectable change were also calculated. The usability of the VR system was measured using the Spanish version of the System Usability Scale.

Results

The mean CROM values in each axis of movement were compatible with those described in the literature. ICC values ranged between 0.86 and 0.96 in the intra-rater analysis and between 0.83 and 0.97 in the inter-rater analysis; these values were between good and excellent. When applying the correction of the trunk movements, both the intra-rater and inter-rater ICC values slightly worsened except in the case of the lateral flexion movement, where they slightly improved. The usability score of the CROM assessment/VR system was 86 points, which is an excellent usability score.

Conclusion

The reliability of the measurements and the usability of the system indicate that a VR setup can be used to assess CROM. The reliability of the VR setup can be affected by slippage of the HMD or tracker. Both slippage errors are additive, i.e., only when the sum of these two errors is less than the compensatory movement do the measurements improve when considering the tracker data.

Neck Pain: Do We Know Enough About the Sensorimotor Control System?

Neck pain is a worldwide health problem. Clarifying the etiology and providing effective interventions are challenging for the multifactorial nature of neck pain. As an essential component of cervical spine function, the sensorimotor control system has been extensively studied in both healthy and pathological conditions. Proprioceptive signals generated from cervical structures are crucial to normal cervical functions, and abnormal proprioception caused by neck pain leads to alterations in neural plasticity, cervical muscle recruitment and cervical kinematics. The long-term sensorimotor disturbance and maladaptive neural plasticity are supposed to contribute to the recurrence and chronicity of neck pain. Therefore, multiple clinical evaluations and treatments aiming at restoring the sensorimotor control system and neural plasticity have been proposed. This paper provides a short review on neck pain from perspectives of proprioception, sensorimotor control system, neural plasticity and potential interventions. Future research may need to clarify the molecular mechanism underlying proprioception and pain. The existing assessment methods of cervical proprioceptive impairment and corresponding treatments may need to be systematically reevaluated and standardized. Additionally, new precise motor parameters reflecting sensorimotor deficit and more effective interventions targeting the sensorimotor control system or neural plasticity are encouraged to be proposed.

Abnormal Foot Progression Angle Kinematics in Cervical Dystonia Improved After Osteopathic Manipulative Medicine: A Prospective Case Series

Introduction Cervical dystonia (CD), a rare disorder, is the most common form of dystonia, a movement disorder. Impairments in activities of daily living and quality of life may result from chronic pain, perceived stigma, difficulty walking, and/or lack of control over movements. Studies of treatments for difficulty walking in CD have been inconclusive. Osteopathic manipulative medicine (OMM) has been used to improve gait biomechanics in other health conditions. Foot progression angle (FPA) while walking indicates functional gait abnormalities that increase the risk of knee injury and osteoarthritis. Objective The aim of this study is to test if five-weekly treatments using an OMM sequence designed for CD improved abnormal gait biomechanics in individuals with CD by identifying and addressing somatic dysfunctions. Methods In this prospective case series, independently ambulating individuals with CD symptom onset before the age of 40 years, not due to traumatic injury, were evaluated utilizing validated scales for severity (Toronto western spasmodic torticollis rating scale [TWSTRsI]) and symptoms affecting quality of life (Cervical Dystonia Impact Profile [CDIP-58]), physical examination, and FPA before and after five-weekly OMM treatments. Lower body joint range of motion and angles were captured in a clinical gait lab by nine cameras collecting three-dimensional Whole-body position data during three trials of one gait cycle at participant-selected walking speed. The FPA waveforms during the gait cycle were quantified by Vicon Nexus and Polygon applications. Pretreatment and posttreatment results were compared to established healthy gait waveforms and tested by repeated measures ANOVA (α=0.05). Results Pretreatment waveforms in CD had a mean 5.13° of excess FPA during gait cycle phases requiring lower-extremity pronation compared to previously published age-gender-matched healthy waveforms. There was 96% improvement in pronation after five treatments, with a mean 0.21° (p=0.041) of excess FPA. Mean TWSTRs and CDIP-58 scores improved. On physical examination, the rotational direction of C2 vertebrae was contralateral to neck muscle hypertonicity. Vertical sphenobasilar synchondrosis strains were present in those with anterotorticollis. Participants had ipsilateral anterolateral neck muscle and anterolateral abdominal wall muscle hypertonicity. All patients had pelvic somatic dysfunctions with left-side superior relative to right-side and restriction from lower-extremity pronation (i.e., supination dysfunctions). Conclusion The FPA was significantly improved after treatment. This OMM sequence was well tolerated and may be useful for improving gait kinematics in individuals with CD. Randomized, controlled, long-term studies are needed to determine effectiveness.

Using cervical movement velocity to assist the prediction of pain and functional recovery for people with chronic mechanical neck pain

BACKGROUND

Impaired cervical kinematics particularly the movement velocity had been consistently found in people with neck pain. The recovery and potential of cervical movement velocity in assisting the prediction of recovery in individuals with chronic neck pain remained unknown. This study investigated the application of cervical movement velocity to predict the outcomes of pain intensity and functional disability for a cohort of participants with chronic mechanical pain after completion of a 12-week intervention program.

METHODS

Cervical movement velocity when performing neck motions in the anatomical planes, pain intensity and functional disability score were assessed before and after the physiotherapy program. Correlations between kinematic and clinical outcomes, and validity of applying the peak velocity values of the cervical spine measured at baseline for prediction of recovery of pain and function after the physiotherapy program were examined (n = 68).

FINDINGS

Significant improvements were found in the peak values of cervical velocity in all movement planes, pain intensity and functional disability score at post-program reassessment (p < 0.001). Significant negative correlations between peak values of cervical movement velocity and pain intensity (for specific directions, r = -0.163 to -0.191), and functional disability were found (for all directions, r = -0.158 to -0.282). Area under the Receiver Operating Characteristics curve was >0.6 for cervical extension, flexion and right rotation velocity for predicting functional recovery post-program.

INTERPRETATION

These findings suggest that cervical velocity of selected planes measured at baseline may inform the prediction of recovery of functional disability but not pain intensity in people with chronic mechanical neck pain.

Head kinematics in patients with neck pain compared to asymptomatic controls: a systematic review

BACKGROUND

Neck pain is one of the most common musculoskeletal disorders encountered by healthcare providers. A precise assessment of functional deficits, including sensorimotor control impairment, is regarded necessary for tailored exercise programmes. Sensorimotor control can be measured by kinematic characteristics, such as velocity, acceleration, smoothness, and temporal measures, or by assessing movement accuracy. This systematic review aims to identify movement tasks and distinct outcome variables used to measure kinematics and movement accuracy in patients with neck pain and present their results in comparison to asymptomatic controls.

METHODS

Electronic searches were conducted in MEDLINE, PEDro, Cochrane Library and CINAHL databases from inception to August 2020. Risk of bias of included studies was assessed. Movement tasks and specific outcome parameters used were collated. The level of evidence for potential group differences in each outcome variable between patients with neck pain and controls was evaluated.

RESULTS

Twenty-seven studies examining head kinematics and movement accuracy during head-aiming, functional and unconstrained movement tasks of the head were included. Average Risk of Bias of included studies was moderate. In total, 23 different outcome variables were assessed. A strong level of evidence for an increased movement time and for an increased number of errors during head aiming tasks was found. Moderate evidence was found in traumatic neck pain for a decreased mean velocity, peak acceleration, and reaction time, and for point deviation and time on target during head aiming tasks. Moderate evidence was found for decreased acceleration during unconstrained movements, too. Results on the remaining movement task and outcome variables showed only limited, very limited or even conflicting level of evidence for patients with neck pain to differ from controls.

CONCLUSIONS

Sensorimotor control in NP in the way of kinematic and movement accuracy characteristics of head motion was examined in head aiming, functional or unconstrained movement tasks. The results from this review indicate that for some characteristics that describe sensorimotor control, patients with NP differ from healthy controls.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number: CRD42020139083.

Analysis of sensorimotor control in people with and without neck pain using inertial sensor technology: study protocol for a 1-year longitudinal prospective observational study

INTRODUCTION

Neck pain is a very common musculoskeletal disorder associated with high socioeconomic costs derived from work absenteeism and medical expenses. Previous studies have suggested that patients with neck pain of different origins present sensorimotor control impairments compared with the asymptomatic population. However, there is a small number of published studies focusing on these with conflicting results. In addition, the existing methodological limitations highlight the need for more and better quality studies. Moreover, longitudinal studies are necessary to investigate whether changes in pain or disability in individuals with chronic neck pain over time associate with changes in cervical sensorimotor control.

METHODS AND ANALYSIS

This is a descriptive, observational, longitudinal, prospective study consecutively enrolling 52 patients with non-specific neck pain and 52 age-matched asymptomatic participants.Intensity of pain, neck disability, duration of symptoms, topography of pain and comorbidities will be registered at baseline. Sensorimotor control variables including active range of motion, movement speed, acceleration, smoothness of motion, head repositioning accuracy and motion coupling patterns will be recorded as primary outcomes by means of inertial sensors during the following tests consecutively performed in two sessions separated by 12 months: (1) kinematics of planar movements, (2) kinematics of the craniocervical flexion movement, (3) kinematics during functional tasks and (4) kinematics of task-oriented neck movements in response to visual targets.Secondary outcomes will include: (1) Regular physical activity levels, (2) Kinesiophobia, (3) Symptoms related to central sensitisation and (4) The usability of the inertial measurement unit sensor technology.

ETHICS AND DISSEMINATION

This study was approved by the Research Ethics Committee of CEU San Pablo University (495/21/39). Patients will be recruited after providing written informed consent and they will be able to withdraw their consent at any time. Only the study investigators will have access to the study data. The results will be disseminated through scientific publications, conferences and media.

TRIAL REGISTRATION NUMBER

NCT05032911.

The study of respiratory muscles activation during respiratory muscle strength effort in adult females with chronic neck pain

[Purpose] This study aimed to compare maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP) values and muscle activity during MIP and MEP between chronic neck pain and healthy participants. [Participants and Methods] Twenty chronic neck pain and 20 non-symptomatic females participated in this study. Maximal airway pressure (MIP and MEP) and surface electromyography (sEMG) for both sides of the upper trapezius, anterior scalene, pectoralis major and 6th intercostal muscles were recorded simultaneously. [Results] Significant differences of MIP and MEP values were found between the groups. The muscle activities of both sides of upper trapezius and 6th intercostal muscles during MEP were significantly higher in the chronic neck pain group than the healthy group except both sides of anterior scalene and pectoralis major muscles. During MIP, the activities of upper trapezius, 6th intercostal muscles and anterior scalene were significantly different between the two studied groups. Higher activity of left pectoralis major was found in the chronic neck pain group. [Conclusion] Decreasing values of MEP and MIP as well as muscles activities elevation in chronic neck pain participants were clearly demonstrated. Besides the musculoskeletal treatment, we suggest breathing exercise training to be considered in treatment programs.

Novel assessment of the variation in cervical inter-vertebral motor control in a healthy pain-free population

Spinal control at intervertebral levels is dependent on interactions between the active, passive and neural control elements. However, this has never been quantifiable, and has therefore been outside the reach of clinical assessments and research. This study used fluoroscopy during repeated unconstrained flexion and return neck movements to calculate intersegmental motor control (MC), defined as the difference and variation in repeated continuous angular motion from its average path. The study aimed to determine control values for MC at individual levels and its variability. Twenty male volunteers aged 19–29 received fluoroscopic screening of their cervical spines during 4 repetitions of neutral to full flexion and return motion. Moving vertebral images from C0–C1 to C6–C7 were tracked using cross-correlation codes written in Matlab. MC for each level was defined as the mean of the absolute differences between each repetition’s angular path and their mean and its variability as represented by the SD. 1-way ANOVA and Tukey multiple comparisons were used to identify significant contrasts between levels. The mean MC differences and SDs were highest at C1-2, suggesting that this level has the least control and the most variability. Results at this level alone were highly significant (F-ratio 10.88 and 9.79 P < 0.0001). Significant contrasts were only found between C1-C2 and all other levels. The mean MC difference for summed C1-6 levels was 3.4° (0.7–6.1). This study is the first to quantify intervertebral MC in the cervical spine in asymptomatic people. Studies of neck pain patients are now merited.

Validity and reliability of a sensor-based electronic spinal mobility index for axial spondyloarthritis

OBJECTIVE

To evaluate the validity and reliability of inertial measurement unit (IMU) sensors in the assessment of spinal mobility in axial spondyloarthritis (axSpA).

METHODS

A repeated measures study design involving 40 participants with axSpA was used. Pairs of IMU sensors were used to measure the maximum range of movement at the cervical (Cx) and lumbar (Lu) spine. A composite IMU score was defined by combining the IMU measures. Conventional metrology and physical function assessment were performed. Validation was assessed considering the agreement of IMU measures with conventional metrology and correlation with physical function. Reliability was assessed using intra-class correlation coefficients (ICCs).

RESULTS

The composite IMU score correlated closely (r = 0.88) with the BASMI. Conventional Cx rotation and lateral flexion tests correlated closely with IMU equivalents (r = 0.85, 0.84). All IMU movement tests correlated strongly with BASFI, while this was true for only some of the BASMI tests. The reliability of both conventional and IMU tests (except for chest expansion) ranged from good to excellent. Test-retest ICCs for individual conventional tests varied between 0.57 and 0.91, in comparison to a range from 0.74 to 0.98 for each of the IMU tests. Each of the composite regional IMU scores had excellent test-retest reliability (ICCs=0.94-0.97), comparable to the reliability of the BASMI (ICC=0.96).

CONCLUSION

Cx and Lu spinal mobility measured using wearable IMU sensors is a valid and reliable assessment in multiple planes (including rotation), in patients with a wide range of axSpA severity.

Effects of Virtual Reality versus Exercise on Pain, Functional, Somatosensory and Psychosocial Outcomes in Patients with Non-specific Chronic Neck Pain: A Randomized Clinical Trial

Background: Virtual reality (VR) applied to patients with neck pain is a promising intervention to produce positive effects when used alone or combined with exercise. Therefore, the objective of this manuscript is to compare the effects of VR versus exercise treatment on pain intensity, conditioned pain modulation (CPM), temporal summation (TS) and functional and somatosensory outcomes in patients with non-specific chronic neck pain (NS-CNP). Methods: A single-blinded, randomized clinical trial was carried out. A total sample of 44 patients with NS-CNP was randomized into a VR treatment group or neck exercises group. The intervention consisted of two treatment sessions per week, for four weeks and eight sessions. Four measurement moments (at baseline, immediately, 1 month, and 3 months after intervention) were considered. Pain intensity, CPM, TS, functional and somatosensory outcomes were measured. Results: Statistically significant differences were revealed for time factor (F = 16.40, p < 0.01, ηp2 = 0.28) and group*time interaction for kinesiophobia (F = 3.89, p = 0.01, ηp2 = 0.08) showing post-hoc differences in favor of the VR group at 3 months (p < 0.05, d = 0.65). Significant effects were shown for time factor (p < 0.05) but not for the group*time interaction (p > 0.05) for pain intensity, rotation range of motion (ROM), Neck Disability Index, pain catastrophizing, fear-avoidance beliefs, left side pressure pain threshold (PPT) and anxiety. Statistically significant differences were not found for time factor (p > 0.05) and neither in group*time interaction (p > 0.05) for CPM, TS, right side PPT, flexo-extension and lateral-flexion ROM. Conclusions: Kinesiophobia was the only outcome that showed differences between VR and exercise at 3 months. Nevertheless, pain intensity, CPM, TS, ROM, neck disability, pain catastrophizing, fear-avoidance beliefs, PPT and anxiety did not show differences between both interventions.

Paths of the cervical instantaneous axis of rotation during active movements-patterns and reliability

The instantaneous helical axis (IHA) is a characteristic of neck movement that is very sensitive to changes in coordination and that has potential in the assessment of functional alterations. For its application in the clinical setting, normative patterns must be available, and its reliability must be established. The purpose of this work is to describe the continuous paths of the IHA during cyclic movements of flexion-extension (FE), lateral bending (LB), and axial rotation (AR) and to quantify their reliability. Fifteen healthy volunteers participated in the study; two repetitions were made on the same day (by different operators) and over an 8-day interval (by the same operator) to evaluate the inter-operator and inter-session reliability, respectively. The paths described by the IHA suggest a sequential movement of the vertebrae in the FE movement, with a large vertical displacement (mean, 10 cm). The IHA displacement in LB and AR movements are smaller. The paths described by the IHAs have a very high reliability for FE movement, although it is somewhat lower for LB and RA movements. The standard error of measurement (SEM) is less than 0.5 cm. These results show that the paths of the IHA are reliable enough to evaluate changes in the coordination of intervertebral movement. Graphical abstract A video photogrammetry system is used to record the cyclic movements of the neck, from which the continuous trajectories of the associated instantaneous helical axis (IHA) are calculated. We have analyzed the movements of flexion-extension (FE), lateral flexion (LB), and axial rotation (AR) for a sample of 15 healthy subjects. The measurements have been repeated with two different operators (in the same session) and in two separate sessions (same operator). IHA displacement patterns have been obtained in each movement, and the reliability of the measurement of such IHA trajectories has been estimated.

DYSKIMOT: An Ultra-Low-Cost Inertial Sensor to Assess Head's Rotational Kinematics in Adults during the Didren-Laser Test

Various noninvasive measurement devices can be used to assess cervical motion. The size, complexity, and cost of gold-standard systems make them not suited to clinical practice, and actually difficult to use outside a dedicated laboratory. Nowadays, ultra-low-cost inertial measurement units are available, but without any packaging or a user-friendly interface. The so-called DYSKIMOT is a home-designed, small-sized, motion sensor based on the latter technology, aiming at being used by clinicians in "real-life situations". DYSKIMOT was compared with a gold-standard optoelectronic system (Elite). Our goal was to evaluate the DYSKIMOT accuracy in assessing fast head rotations kinematics. Kinematics was simultaneously recorded by systems during the execution of the DidRen Laser test and performed by 15 participants and nine patients. Kinematic variables were computed from the position, speed and acceleration time series. Two-way ANOVA, Passing-Bablok regressions, and dynamic time warping analysis showed good to excellent agreement between Elite and DYSKIMOT, both at the qualitative level of the time series shape and at the quantitative level of peculiar kinematical events' measured values. In conclusion, DYSKIMOT sensor is as relevant as a gold-standard system to assess kinematical features during fast head rotations in participants and patients, demonstrating its usefulness in both clinical practice and research environments.

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.

A Novel Virtual Reality Technique (Cervigame®) Compared to Conventional Proprioceptive Training to Treat Neck Pain: A Randomized Controlled Trial

Background

Despite the potential benefits of virtual reality technology in physical rehabilitation, only a few studies have evaluated the efficacy of this type of treatment in patients with neck pain.

Objective

The aim of this study was to compare the effects of virtual reality training (VRT) versus conventional proprioceptive training (CPT) in patients with neck pain.

Materials and Methods

Forty four participants with nonspecific chronic neck pain were randomly assigned to VRT or CPT in this assessor-blinded clinical trial. A novel videogame called Cervigame® was designed for VRT. It comprises of 50 stages divided into unidirectional and two-directional stages ordered from easy to hard. CPT consisted of eye-follow, gaze stability, eye-head coordination and position and movement sense training. Both groups completed 8 training sessions over 4 weeks. Visual analogue scale score, neck disability index and Y-balance test results were recorded at baseline, immediately after and 5 weeks post-intervention. Mixed repeated measure ANOVA was used to analyze differences between mean values for each variable at an alpha level of 0.05.

Results

There were significant improvements in all variables in both groups immediately after and 5 weeks after the intervention. Greater improvements were observed in the visual analogue scale and neck disability index scores in VRT group, and the results for all directions in Y-balance test were similar in both groups. No side effects were reported.

Conclusion

Improvements in neck pain and disability were greater in VRT than CPT group. Cervigame® is a potentially practical tool for rehabilitation in patients with neck pain.

Experimental cervical interspinous ligament pain altered cervical joint motion during dynamic extension movement

BACKGROUND

Although the cervical interspinous ligament is a potential source of neck pain, the effects on cervical joint motion and pressure pain sensitivity has never been investigated. The understanding of the relationship will broaden our understanding of cervical biomechanics and improve diagnosis and treatment of neck pain.

METHODS

Fluoroscopy videos of cervical flexion and extension movements and pressure pain thresholds over bilateral C2/C3 and C5/C6 facet joints were collected in fifteen healthy subjects before and after injections of hypertonic and isotonic saline in C4/C5 ISL. The videos were divided into 10 even epochs and the motion of individual joints during each epoch was extracted. Joint motion parameters including anti-directional motion, pro-directional motion, total joint motion and joint motion variability were extracted across epochs. Joint motion parameters and PPTs were compared before and after injection of hypertonic and isotonic saline separately.

FINDINGS

Compared with baselines: hypertonic saline injection 1) decreased anti-directional motion and joint motion variability at C4/C5 (P < 0.05) and increased at C2/C3 (P < 0.05) during extension; 2) increased total joint motion of C0/C1 during first half range (P < 0.05) and decreased during second half range of extension, and total joint motion of C2/C3 increased during second half range of extension (P < 0.05) and; 3) increased pressure pain thresholds over left C2/C3 facet joint (P < 0.01).

INTERPRETATION

The cervical interspinous ligament pain redistributed anti-directional motion between C4/C5 and C2/C3 during dynamic extension and decreased pressure pain sensitivity over the left C2/C3 facet joint.

Origin of neck pain and direction of movement influence dynamic cervical joint motion and pressure pain sensitivity

BACKGROUND

Patients with neck pain normally showed alterations in cervical motion and pressure pain sensitivity. Cervical joints show scattered motions opposite to (anti-directional) the primary motion direction (pro-directional) during dynamic cervical flexion and extension. This study aimed to assess dynamic cervical joint motion and pressure pain sensitivity when pain originated from different cervical muscles which may have clinical relevance in diagnosis of impairments related with neck pain.

METHODS

Fluoroscopic video recordings of cervical flexion and extension were collected from fifteen healthy subjects before and during hypertonic saline-induced pain in right multifidus and trapezius muscles. Cervical flexion and extension motions were divided into 10 epochs with respect to time. Pro-directional, anti-directional, and total joint motion were extracted across epochs as well as joint motion variability. Pressure pain thresholds (PPTs) were assessed bilaterally over C2/C3 and C5/C6 facet joints.

FINDINGS

Compared with baseline: 1) Multifidus muscle pain increased the C3/C4 anti-directional motion (P < 0.01), decreased the C6/C7 anti-directional motion (P < 0.05) during extension, and redistributed total joint motion between joints and between half ranges during flexion (P < 0.05). 2) Trapezius muscle pain decreased pro-directional motion (P < 0.05), anti-directional motion (P < 0.05), and joint motion variability (P < 0.05) during extension. 3) Trapezius and multifidus muscle pain increased the PPTs bilaterally over C2/C3 and on the left side of C5/C6 facet joints (P < 0.05).

INTERPRETATION

The direction of motion influenced the effects of experimental muscle pain on dynamic cervical joint kinematics, and deep muscle pain showed local effects on individual joints while superficial muscle pain showed global effects spread to all joints.

Spinal kinematics during smartphone texting - A comparison between young adults with and without chronic neck-shoulder pain

To advance our understanding about the association between smartphone use and chronic neck-shoulder pain, the objective of this study was to compare spinal kinematics between different text-entry methods in smartphone users with and without chronic neck-shoulder pain. Symptomatic (n = 19) and healthy participants (n = 18) were recruited and they performed three tasks: texting on a smartphone with one hand, with two hands, and typing on a desktop computer. Three-dimensional kinematics were examined in the cervical, thoracic and lumbar regions for each task. This study suggests that altered kinematics may be associated with pain since significantly increased angles of cervical right side flexion during smartphone texting and greater postural changes in cervical rotation were found during all text-entry tasks in the symptomatic group. Two-handed texting was associated with increased cervical flexion while one-handed texting was correlated with an asymmetric neck posture, indicating both text-entry methods are not favorable in terms of spinal postures.

Multi-segmental thoracic spine kinematics measured dynamically in the young and elderly during flexion

In contrast to the cervical and lumbar region, the normal kinematics of the thoracic spine have not been thoroughly investigated. The aim of this study was to characterize normal multi-segmental continuous motion of the whole thoracolumbar spine, during a flexion maneuver, in young and elderly subjects. Forty-two healthy volunteers were analyzed: 21 young (age=27.00±3.96) and 21 elderly (age=70.1±3.85). Spinal motion was recorded with a motion-capture system and analyzed using a 3rd order polynomial function to approximate spinal curvature throughout the motion sequence. The average motion profiles of the two age groups were characterized. Flexion timing of the thoracic region of the spine, as compared to the lumbar spine and hips, was found to be different in the two age groups (p=0.011): a delayed/sequential motion type was observed in most of the young, whereas mostly a simultaneous motion pattern was observed in the elderly subjects. A similar trend was observed in flexion of the lower thoracic segments (p=0.017). Differences between age groups were also found for regional and segmental displacements and velocities. The reported characterization of the thoracic spine kinematics may in the future support identification of abnormal movement or be used to improve biomechanical models of the spine.

An Objective Functional Characterisation of Head Movement Impairment in Individuals with Neck Muscle Weakness Due to Amyotrophic Lateral Sclerosis

Background

Neck muscle weakness and head drop are well recognised in patients with Amyotrophic lateral sclerosis (ALS), but an objective characterisation of the consequent head movement impairment is lacking. The aim of this study was to quantitatively characterise head movements in ALS compared to aged matched controls.

Methods

We evaluated two groups, one of thirteen patients with ALS and one of thirteen age-matched controls, during the execution of a series of controlled head movements, performed while wearing two inertial sensors attached on the forehead and sternum, respectively. We quantified the differences between the two groups from the sensor data using indices of velocity, smoothness and movement coupling (intended as a measure of undesired out of plane movements).

Findings

Results confirmed a general limitation in the ability of the ALS patients to perform and control head movements. High inter-patient variability was observed due to a wide range of observed functional impairment levels. The ability to extend the head backward and flex it laterally were the most compromised, with significantly lower angular velocity (P < 0.05, Cohen’s d > 0.8), reduced smoothness and greater presence of coupled movements with respect to the controls. A significant reduction of angular velocity (P < 0.05, Cohen’s d > 0.8) in extension, axial rotation and lateral flexion was observed when patients were asked to perform the movements as fast as possible.

Interpretation

This pilot study is the first study providing a functional objective quantification of head movements in ALS. Further work involving different body areas and correlation with existing methods of evaluating neuromuscular function, such as dynamometry and EMG, is needed to explore the use of this approach as a marker of disease progression in ALS.

Relationship between neck acceleration and muscle activation in people with chronic neck pain: Implications for functional disability

BACKGROUND

Previous study has found that people with chronic neck pain moved with a consistently compromised acceleration/deceleration at their cervical and thoracic spines. This study examined the strength of the association between the electromyographic activities and the acceleration/deceleration of the cervical and thoracic spine, and its correlation with the functional disabilities in individuals with neck pain.

METHODS

Time history of the cervical and thoracic acceleration/deceleration and EMG activity was acquired in thirty-four subjects with chronic neck pain and thirty-four age- and gender-matched asymptomatic subjects during active neck movements. The strength of the association between the electromyographic activity of spinal muscles and the cervical and thoracic acceleration/deceleration was determined using cross-correlation method. Relationship between the strength of this association and the severity of the functional disabilities in neck pain group was examined using correlation analysis.

FINDINGS

The strength of the association between cervical and thoracic acceleration/deceleration and electromyographic activities was significantly lower in neck pain group. Significant negative correlations were found between the functional disability level and the strength of this defined association in the symptomatic group.

INTERPRETATION

The compromised capability of the spinal muscles to produce acceleration/deceleration in the neck pain group may imply an impaired electromechanical coupling of these spinal muscles when performing neck movements. Significant negative correlation of the degree of functional disabilities suggests that the present approach can be used as an objective and specific evaluation of the dynamic performance of the spinal muscles and its relationship with the functional disabilities in neck pain subjects.

Hip Strength Testing of Soccer Players With Long-Standing Hip and Groin Pain: What are the Clinical Implications of Pain During Testing?

OBJECTIVE

To investigate whether self-reported pain during hip strength testing correlates to a large degree with hip muscle strength in soccer players with long-standing unilateral hip and groin pain.

DESIGN

Cross-sectional study.

SETTING

Clinical assessments at Sports Orthopaedic Research Center-Copenhagen (SORC-C), Arthroscopic Centre Amager, Copenhagen University Hospital, Denmark.

PARTICIPANTS

Twenty-four male soccer players with unilateral long-standing hip and groin pain.

INTERVENTIONS

The soccer players performed 5 reliable hip muscle strength tests (isometric hip flexion, adduction, abduction, isometric hip flexion-modified Thomas test, and eccentric hip adduction).

MAIN OUTCOME MEASURES

Muscle strength was measured with a hand-held dynamometer, and the players rated the pain during testing on a numerical rating scale (0-10).

RESULTS

In 4 tests (isometric hip adduction, abduction, flexion, and eccentric adduction), no significant correlations were found between pain during testing and hip muscle strength (Spearman rho = -0.28 to 0.06, P = 0.09-0.39). Isometric hip flexion (modified Thomas test position) showed a moderate negative correlation between pain and hip muscle strength (Spearman rho = -0.44, P = 0.016).

CONCLUSIONS

Self-reported pain during testing does not seem to correlate with the majority of hip muscle strength tests used in soccer players with long-standing hip and groin pain.

Rater Reliability and Concurrent Validity of Single and Dual Bubble Inclinometry to Assess Cervical Lateral Flexion

OBJECTIVE

The purpose of this study was to assess interrater and intrarater reliability and validity for single inclinometry (SI) and dual inclinometry (DI) assessment of cervical lateral flexion (CLF) range of motion and compare reliability in a practicing physical therapist (PT) and student PTs (SPTs).

METHODS

Twenty-four subjects performed right and left CLF while SI, DI, and 3-dimensional kinematics were concurrently recorded. Subjects were reassessed by 2 SPTs and 1 PT using both SI and DI. Each subject was measured twice per rater in round-robin fashion.

RESULTS

There were significant positive relationships between DI and motion capture for both right (r = 0.841; P < .01) and left lateral flexion (r = 0.838; P < .01). Single inclinometry also had a significant correlation with motion capture for right (r = 0.927, P < .01) and left (r = 0.834, P < .01) lateral flexion. Interrater reliability was good for both SI and DI methods. For SI, intraclass correlation coefficient (ICC) (3,1) was 0.905 and 0.870 for right and left CLF, respectively. For DI, ICC(3,1) was 0.803 and 0.757 for right and left CLF, respectively. Intrarater reliability was good for both methods. Average SI values were ICC(2,1) of 0.928 and 0.897 for right and left CLF, respectively. Average DI values were ICC(2,1) of 0.882 and 0.851 for left and right, respectively. Although not significant, the PT had slightly higher reliability in all measures (range, 0.881-0.935) compared to the SPTs (range, 0.880-0.925).

CONCLUSIONS

Both SI and DI are acceptable for clinical use and both are reliable measurement methods for CLF between raters and for repeated measures. There are minimal differences in reliability between a PT with experience and SPTs with minimal experience.

Correlation varies with different time lags between the motions of the hyoid bone, epiglottis, and larynx during swallowing

Although coordination and timing of swallowing have often been investigated by using discrete timing events such as the onset, peak, and duration of specific motions, the sequence and duration of swallowing events cannot represent the coordination of the swallowing mechanism quantitatively. This study aimed to apply a cross-correlation analysis of the motions of the hyolaryngeal structures during swallowing as an objective method for measuring the coordination and timing of the motions. Forty healthy subjects swallowed 2 and 5 ml of diluted barium solution (35 %) and 5 ml of curd yogurt under videofluoroscopy. Hyolaryngeal motions in videofluoroscopic images were digitized using the motion analysis system. The time series of the horizontal and vertical hyoid motion, the laryngeal elevation, and the angle of the epiglottic tilt were analyzed using cross-correlation at each 1/60-s time lag. The results showed high and consistent cross-correlations between hyolaryngeal motions during swallowing in most of the subjects regardless of age and bolus type. The horizontal hyoid motion and laryngeal elevation were more strongly correlated with the epiglottic tilt than the vertical hyoid motion, which might suggest the mechanism of the epiglottic tilt during swallowing. The bolus volume and viscosity affected the correlation coefficients and time lags between the hyolaryngeal motions, particularly those related to the epiglottic tilt. The results suggest that cross-correlation analysis may be used for measuring the coordination and timing of swallowing. Further studies using cross-correlation analysis of additional physiological factors related to swallowing or pathological conditions are warranted.