Cervical Kinematics Research Articles

Cervical motion analysis using wearable inertial sensors to patients with cervical ossification of posterior longitudinal ligament.

This study aimed to clarify cervical kinematics during daily activities, including level walking and stair ascending, in patients with cervical ossification of the posterior longitudinal ligament (C-OPLL). Eighteen patients with myelopathy caused by C-OPLL and 18 healthy controls were recruited to participate in the study. The sagittal cervical kinematics during level walking and stair ascent were quantitatively assessed using a motion analysis system based on wearable inertial sensors. The Japanese Orthopaedic Association score, Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire, Neck Disability Index, and deep sensation in the lower extremities were assessed in all participants. Nine of 18 patients with C-OPLL presented with deep sensory disturbances. Patients with C-OPLL with deep sensory disturbances exhibited different sagittal plane cervical motion patterns than healthy controls during level walking and stair ascent. During the first phase of stair ascent, both patients with C-OPLL and healthy controls flexed their necks to the same degree; however, during the middle and final phases of stair ascent and all phases of level walking, the mean cervical flexion angle of patients with C-OPLL with deep sensory disturbances was significantly higher than that of patients with C-OPLL without deep sensory disturbance and healthy controls. Our data suggest that patients with C-OPLL presenting with deep sensory disturbances are likely to walk with their necks flexed and gaze downward to observe their steps throughout their daily lives. This habitual neck posture may lead to a vicious cycle of cervical kyphosis and worsening of compressive myelopathy.

Sensory-motor training with virtual reality as a complementary intervention to manual therapy for persistent non-specific neck pain: a randomized controlled trial.

Persistent non-specific neck pain (NP) is a widespread condition described as a complex biopsychosocial disorder, characterized by physical and psychological symptoms. Virtual reality (VR) shows promise in NP treatment, potentially reducing pain, kinesiophobia, and improving range of motion (ROM) and motor control. The primary aim of the study was to assess the effectiveness of VR sensorimotor training, combined with manual therapy, in reducing the level of disability in persistent non-specific NP individuals. The secondary aim was to determine if this VR-enhanced approach also contributes to improvement in overall function, pain perception and kinesiophobia. Monocentric, single-blind, randomized controlled trial. We conducted this trial at San Raffaele Scientific Institute, Department of Rehabilitation and Functional Recovery, Milan, Italy. Forty NP participants were enrolled in the study and randomly allocated into two groups. The study involved a 6-week rehabilitation program, comprising 12 sessions of 45 minutes each, twice weekly. Both intervention groups underwent manual therapy as a consistent component of their treatment. The Experimental Group (VRT) was additionally engaged in sensorimotor rehabilitation exercises using Virtual Reality, whereas the Control Group (CT) performed the same exercises without VR. We assessed subjects at baseline (T0) and after six weeks of rehabilitation (T1). The primary outcome was the disability (Neck Disability Index) while the secondary outcomes were: pain perception (Numeric Rating Scale, NP and Disability Scale, Central Sensitization Inventory) function (Cervical Kinematics) and kinesiophobia (Tampa Scale of Kinesiophobia). Both groups demonstrated significant reduction in level of disability, pain perception, and kinesiophobia. Significant advancements in kinematics were observed: VRT group showed enhanced ROM during craniocervical rotation (P=0.039), lateral bending (P=0.001), flexion-extension (P=0.009), and mean velocity across movements (P<0.001), whereas CT group improved in maximal ROM during lateral bending rotation (P=0.001). Between-group analysis, after Bonferroni's correction for multiple comparisons, revealed that VRT group had significantly better outcomes in ROM during rotation (P=0.040), ratio of the primary over the secondary movement while performing rotation (P=0.021), and mean velocity during lateral bending (P=0.031). Sensorimotor training, combined with manual therapy, could enhance kinematic outcomes for NP patients, supporting the potential of VR in rehabilitation. This study highlighted that both groups demonstrated significant reduction in level of disability, pain perception, and kinesiophobia after sensorimotor training combined with manual therapy. It is important to underscore that in terms of reducing the level of neck disability, both interventions proved to be equally effective. This parity in efficacy is a critical finding, reaffirming the robustness of our therapeutic approaches for this specific outcome.

Assessing accuracy of measurement methods for bony fusion assessment after anterior cervical discectomy

BACKGROUND CONTEXTCurrently, there is no universally accepted method for assessing radiological fusion shortly after anterior cervical discectomy. Five-year follow-up radiological X-rays demonstrating solid fusion or absence of fusion provided a gold standard for comparison with various assessment methods. PURPOSEEstablishing the most accurate diagnostic test for earlier bony fusion assessment by comparing different cut-off values for the difference in interspinous distance and the change in Cobb angle on dynamic radiological images against the established gold standard. DESIGNPost-hoc analysis from the NEtherlands Cervical Kinematics (NECK) trial (NTR1289). PATIENT SAMPLEA total of 40 patients with 1 level herniated disc that underwent anterior discectomy between 2010 and 2014 returned for a 5-year follow-up X-ray. OUTCOME MEASURESRadiological outcome was assessed quantitatively and qualitatively by fusion on radiographic images 5 years after surgery. METHODSRadiological dynamic X-rays were reviewed for fusion at 5-year follow-up by a senior spine surgeon. At this timepoint, bony continuity was indisputable and served as gold standard. Cobb angles and interspinous distances on flexion-extension images were measured independently by 2 investigators. Optimum agreement between the gold standard and the 2 methods was assessed, evaluating varying cut-off values, considering sensitivity, specificity, and area under the curve (AUC). RESULTSDynamic radiographic assessments revealed fusion in 29 out of 40 patients (mean age: 49 years ± 8; 23 women). For Cobb angle (optimal cut-off: ≤3.0°), the AUC was 0.86 with 100% sensitivity and 72.7% specificity. For interspinous distance (optimal cut-off: ≤1.5 mm), the AUC was 0.89 with 96.6% sensitivity and 81.8% specificity. The highest AUC (0.91) was observed for combined cut-off values (Cobb angle ≤3.0° and interspinous distance ≤2.0 mm), yielding 100% sensitivity and 81.8% specificity. CONCLUSIONThe combination of cut-off values ≤3.0° difference for Cobb angle and ≤2.0 mm difference for interspinous distance on lateral flexion-extension X-rays was assessed to be an accurate diagnostic criterion for fusion evaluation. This tool provides a practical and easy applicable method for assessing fusion during follow-up after anterior discectomy.

Motion Capture-based 3-dimensional Measurement of Range of Motion in Patients Undergoing Cervical Laminoplasty.

A prospective study. To measure 3-dimensional cervical range of motion (ROM) by noninvasive optical tracking-based motion-capture technology in patients undergoing laminoplasty, and to elucidate the postoperative effects of laminoplasty on cervical mobility. Cervical laminoplasty is a motion-sparing decompression surgery for degenerative cervical myelopathy. Unlike cervical laminectomy and fusion, the true postoperative impact of laminoplasty on neck motion has not been well studied. Participants comprised 25 patients undergoing double-door cervical laminoplasty for degenerative cervical myelopathy in a single center. Maximum flexion/extension, left/right rotation, and left/right side bending were recorded using the motion-capture device preoperatively and 3 months postoperatively. ROMs in 3 orthogonal axes were calculated. Preoperative differences in C2-7 Cobb angles on lateral flexion/extension x-rays were also measured as the radiologic ROM to assess reliability. Preoperative and 1-year postoperative Japanese Orthopaedic Association score, Neck Disability Index [NDI], and Euro-QOL were recorded, and correlations with ROMs were assessed. Preoperative mean (±SD) ROMs for flexion/extension, rotation, and side bending were 90±17, 107±16, and 53±17 degrees, respectively. Although radiologic sagittal ROM measurement showed a smaller range than motion capture, averaging 36±13 degrees, a moderate to strong correlation between radiologic and motion capture values was observed (R=0.57, P=0.003). Preoperative NDI showed a negative correlation with coronal ROM (rho=-0.547, P=0.02). Postoperative ROM showed a significant reduction in rotation (95±16 degrees, P=0.002) but not in flexion/extension or side bending. Three-dimensional motion-capture analysis allowed reliable measurement of cervical ROM. Rotational ROM was significantly reduced after laminoplasty, showing that cervical kinematics are still significantly altered.

Machine learning models for classifying non-specific neck pain using craniocervical posture and movement

ObjectivePhysical therapists and clinicians commonly confirm craniocervical posture (CCP), cervical retraction, and craniocervical flexion as screening tests because they contribute to non-specific neck pain (NSNP). We compared the predictive performance of statistical machine learning (ML) models for classifying individuals with and without NSNP using datasets containing CCP and cervical kinematics during pro- and retraction (CKdPR). DesignExploratory, cross-sectional design. Setting and participantsIn total, 773 public service office workers (PSOWs) were screened for eligibility (NSNP, 441; without NSNP, 332). MethodsWe set up five datasets (CCP, cervical kinematics during the protraction, cervical kinematics during the retraction, CKdPR and combination of the CCP and CKdPR). Four ML algorithms–random forest, logistic regression, Extreme Gradient boosting, and support vector machine–were trained. Main outcome measuresModel performance were assessed using area under the curve (AUC), accuracy, precision, recall and F1-score. To interpret the predictions, we used Feature permutation importance and SHapley Additive explanation values. ResultsThe random forest model in the CKdPR dataset classified PSOWs with and without NSNP and achieved the best AUC among the five datasets using the test data (AUC, 0.892 [good]; F1, 0.832). The random forest model in the CCP dataset had the worst AUC among the five datasets using the test data [AUC, 0.738 (fair); F1, 0.715]. ConclusionML performance was higher for the CKdPR dataset than for the CCP dataset, suggesting that ML algorithms are more suitable than classical statistical methods for developing robust models for classifying PSOWs with and without NSNP.

Influence of cervical total disc replacement on motion in the target and adjacent segments

Background ContextThe motion limitation after cervical discectomy and fusion alters the spine´s kinematics. Unphysiological strains may be the result and possible explanation for adjacent segment degeneration. Alterations to cervical kinematics due to cervical total disc replacement (TDR), especially two-level, are still underinvestigated. PurposeTo investigate cervical motion including coupled motions after one-level and two-level TDR in the treated and also the adjacent segments. Study DesignAn in-vitro study using pure moment loading of human donor spines. MethodsSeven fresh frozen human cervical spine specimens (C4-T1, median age 46 with range 19-60 years, four female) were included in this study. Specimens were tested in the intact condition first, followed by one-level TDR at C5-6 which was subsequently extended one level further caudal (C5-7). Each specimen was quasistatically loaded with pure moments up to 1.5 Nm in flexion/extension (FE), lateral bending (LB) and axial rotation (AR) in a universal spine tester for 3.5 cycles at 1 °/s. During the tests three dimensional motion tracking was performed for each vertebral body individually. From that the primary and coupled ROM of each spinal level during the third full cycle of motion were evaluated. Non-parametric statistical analysis was performed using a Friedman-test and post-hoc correction with Dunn-Bonferroni-tests (p < 0.05). Ethics approval was obtained in advance. ResultsIn FE, one-level TDR (C5-6) moderately increased primary FE in all four segments, but only significantly at the cranial adjacent level C4-5. Additional TDR at C6-7 further increased the ROM at the target segment without much influence on the other levels. Increasing implant height at C6-7 partially counteracted the increased FE. Coupled motions were minimal in all test conditions at all levels.In LB, coupled AR was observed in all test conditions at all levels. One-level TDR decreased primary LB at the target segment C5-6 significantly, without much influence on the other levels. Extending TDR to C6-7 decreased ROM in the target segment but without gaining statistical significance. Increasing implant height at C6-7 further decreased primary LB at the target segment, still without significance. Notably, coupled AR was significantly decreased at the cranial adjacent segment C4-5 compared to the intact condition.In AR, coupled LB was observed in all test conditions at the levels C4-5, C5-6 and C6-7, while the transition level to the thoracic spine C7-T1 showed only little coupled LB. Both one-level and two-level TDR showed little influence on primary AR or coupled motions at any level. Only after increasing implant height at C6-7 was the motion of the caudally adjacent level C7-T1 significantly altered. ConclusionEvaluating primary FE, LB and AR together with the associated coupled motions revealed widespread influence of cervical TDR not only on the motion of the treated level but also at the adjacent segments. The influence of two-level TDR is more widespread and involves more levels than one-level TDR. Clinical SignificanceThe prevention of unphysiological strains due to altered kinematics after cervical fusion, which could possibly explain adjacent segment degeneration, were a driving factor in the development of TDR. These experimental findings suggest cervical TDR influences the whole cervical spine, not only the treated segment. The effect becomes more extensive, involving more levels and motion directions, after two-level than after one-level TDR.

Concurrent Validity of Cervical Movement Tests Using VR Technology-Taking the Lab to the Clinic.

Reduced cervical range of motion (ROM) and movement velocity are often seen in people with neck pain. Objective assessment of movement characteristics is important to identify dysfunction, to inform tailored interventions, and for the evaluation of the treatment effect. The purpose of this study was to investigate the concurrent validity of a newly developed VR technology for the assessment of cervical ROM and movement velocity. VR technology was compared against a gold-standard three-dimensional optical motion capture system. Consequently, 20 people, 13 without and 7 with neck pain, participated in this quantitative cross-sectional study. ROM was assessed according to right/left rotation, flexion, extension, right/left lateral flexion, and four diagonal directions. Velocity was assessed according to fast cervical rotation to the right and left. The correlations between VR and the optical system for cervical ROM and velocity were excellent, with intraclass correlation coefficient (ICC) values > 0.95. The mean biases between VR and the optical system were ≤ 2.1° for the ROM variables, <12°/s for maximum velocity, and ≤3.0°/s for mean velocity. In conclusion, VR is a useful assessment device for ROM and velocity measurements with clinically acceptable biases. It is a feasible tool for the objective measurement of cervical kinematics in the clinic.

Biomechanics of Cervical Disk Replacement: Classifying Arthroplasty Implants.

Cervical disk arthroplasty has been employed with increased frequency over the past 2 decades as a motion-preserving alternative to anterior cervical discectomy and fusion in select patients with myelopathy or radiculopathy secondary to degenerative disk disease. As indications continue to expand, an understanding of cervical kinematics and materials science is helpful for optimal implant selection. Cervical disk arthroplasty implants can be classified according to the mode of articulation and df, articulation material, and endplate construction. The incorporation of translational and rotational df allows the implant to emulate the dynamic and coupled centers of movement in the cervical spine. Durable and low-friction interfaces at the articulation sustain optimal performance and minimize particulate-induced tissue reactions. Endplate materials must facilitate osseous integration to ensure implant stability after primary fixation. These cardinal considerations underlie the design of the 9 implants currently approved by the FDA and serve as the foundation for further biomimetic research and development.

The move-C cervical artificial disc can restore intact range of motion and 3-D kinematics

BACKGROUND CONTEXTIn contrast to cervical discectomy and fusion, total disc replacement (TDR) aims at preserving the motion at the treated vertebral level. Spinal motion is commonly evaluated with the range of motion (ROM). However, more qualitative information about cervical kinematics before and after TDR is still lacking. PURPOSEThe aim of this in vitro study was to investigate the influence of cervical TDR on ROM, instantaneous centers of rotation (ICR) and three-dimensional helical axes. STUDY DESIGNAn in vitro study with human spine specimens under pure moment loading was conducted to evaluate the kinematics of the intact cervical spine and compare it to cervical TDR. METHODSSix fresh frozen human cervical specimens (C4–5, median age 28 years, range 19–47 years, two female and four male) were biomechanically characterized in the intact state and after implantation of a cervical disc prosthesis (MOVE-C, NGMedical, Germany). To mimic in vivo conditions regarding temperature and humidity, water steam was used to create a warm and humid test environment with 37°C. Each specimen was quasistatically loaded with pure moments up to ±2.5 Nm in flexion/extension (FE), lateral bending (LB) and axial rotation (AR) in a universal spine tester for 3.5 cycles at 1 °/s. For each third cycle of motion the ROM was evaluated and an established method was used to determine the helical axis and COR and to project them into three planar X-rays. Statistical analysis was conducted using a Friedman-test and post hoc correction with Dunn-Bonferroni-tests (p<.05). RESULTSAfter TDR, total ROM was increased in FE from 19.1° to 20.1°, decreased in LB from 14.6° to 12.6° and decreased in AR from 17.7° to 15.5°. No statistical differences between the primary ROM in the intact condition and ROM after TDR were detected. Coupled rotation between LB and AR were also maintained. The position and orientation of the helical axes after cervical TDR was in good agreement with the results of the intact specimens in all three motion directions. The ICR in FE and AR before and after TDR closely matched, while in LB the ICR after TDR were more caudal. The intact in vitro kinematics we found also resembled in vivo results of healthy individuals. CONCLUSIONThe results of this in vitro study highlight the potential of artificial cervical disc implants to replicate the quantity as well as the quality of motion of the intact cervical spine. CLINICAL SIGNIFICANCEPhysiological motion preservation was a driving factor in the development of cervical TDR. Our results demonstrate the potential of cervical TDR to replicate in vivo kinematics in all three motion directions.

Comparative study of outcomes between allograft intervertebral disc transplantation and anterior cervical discectomy and fusion: a retrospective cohort study at least 5 years of follow-up

PurposeAdjacent segment degeneration (ASDeg) after anterior cervical discectomy and fusion (ACDF) seriously affects the long-term efficacy of the operation. Therefore, our team has done a lot of research on allograft intervertebral disc transplantation (AIDT) to prove its feasibility and safety. This study will compare the efficacy between AIDT and ACDF in the treatment of cervical spondylosis.MethodsAll patients who received ACDF or AIDT in our hospital from 2000 to 2016 and followed up for at least 5 years were recruited and divided into ACDF and AIDT groups. The clinical outcomes including functional scores and radiological data of both groups were collected and compared preoperatively and postoperatively at 1 week, 3 months, 6 months, 12 months, 24 months, 60 months and last follow-up. Functional scores included Japanese Orthopedic Association score (JOA), Neck Disability Index (NDI), Visual Analog Scale of Neck (N-VAS) and Arms (A-VAS) pain, the Short Form Health Survey-36 (SF-36) and imaging dates including digital radiographs in the lateral, hyperextension and flexion positions to assess the stability, sagittal balance and mobility of the cervical spine and magnetic resonance imaging (MRI) scans to assess the degeneration of adjacent segment.ResultsThere were 68 patients with 25 in AIDT group and 43 in ACDF group. Satisfactory clinical results were obtained in both groups, but the long-term NDI score and N-VAS score in the AIDT group were better. The AIDT obtained the same stability and sagittal balance of the cervical spine as fusion surgery. The range of motion of adjacent segments can be restored to the preoperative level after transplantation, but this increases significantly after ACDF. There were significant differences in the superior adjacent segment range of motion (SROM) between two groups at 12 months (P = 0.039), 24 months (P = 0.035), 60 months (P = 0.039) and the last follow-up (P = 0.011). The inferior adjacent segment range of motion (IROM) and SROM had a similar trend in the two groups. The ratio value of the greyscale (RVG) of adjacent segments showed a downward trend. At the last follow-up, the RVG decreased more significantly in the ACDF group. At the last follow-up, there was a significant difference in the incidence of ASDeg between the two groups (P = 0.000). And the incidence of adjacent segment disease (ASDis) is 22.86% in the ACDF group.ConclusionThe allograft intervertebral disc transplantation may be as an alternative technique to traditional anterior cervical discectomy and fusion for the management of cervical degenerative diseases. For the more, the results showed it would improve cervical kinematics and reduce the incidence of adjacent segment degeneration.

Relative Efficacy of Cervical Total Disc Arthroplasty Devices and Anterior Cervical Discectomy and Fusion for Cervical Pathology: A Network Meta-Analysis.

Systematic Review and Meta Analysis. This study sought to compare patient-reported outcomes, success, complications, and radiographic outcomes directly and indirectly between different cervical total disc arthroplasty (TDA) devices and anterior cervical discectomy and fusion (ACDF). Patients of prospective randomized controlled trials of 1-level cervical TDA with a minimum of 2years follow up were identified in the literature. A frequentist network meta-analysis model was used to compare each outcome across the different TDA devices included and ACDF using the mixed effect sizes. 15 studies were included for quantitative analysis, reporting the outcomes of 2643 patients with an average follow-up was 67.3months (range: 24-120months), 1417 of whom underwent TDA and 1226 of whom underwent ACDF. Nine TDA devices were compared to ACDF, including the Bryan, Discover, Kineflex, M6, Mobi-C, PCM, Prestige ST, ProDisc-C, and Secure-C cervical prostheses. Several devices outperformed ACDF for certain outcomes, including Visual Analog Scale (VAS) Arm, Physical Component Score of the Short-Form Health Survey (SF PCS), neurological success, satisfaction, index-level secondary surgical interventions (SSI), and adjacent level surgeries. Cumulative ranking of each intervention assessed demonstrated the highest performance with the M6 prosthesis (P = .70), followed by Secure-C (P = .67), PCM (P = .57), Prestige ST (P = .57), ProDisc-C (P = .54), Mobi-C (P = .53), Bryan (P = .49), Kineflex (P = .49), Discover (P = .39), and ACDF (P = .14). Cervical TDA was found to be superior on most outcomes assessed in the literature of high-quality clinical trials. While most devices demonstrated similar outcomes, certain prostheses such as the M6 were found to outperform others across several outcomes assessed. These findings suggest that the restoration of near-normal cervical kinematics may lead to improved outcomes.

Dynamic evaluation of the cervical spine by kinematic MRI in patients with cervical spinal cord injury without fracture and dislocation

BackgroundThe pattern of changes in the cervical spine and the spinal cord and their dynamic characteristics in patients with cervical spinal cord injury without fracture and dislocation remain unclear. This study aimed to evaluate the dynamic changes in the cervical spine and spinal cord from C2/3 to C7/T1 in different positions by using kinematic magnetic resonance imaging in patients with cervical spinal cord injury without fracture and dislocation. This study was approved by the ethics committee of Yuebei People's Hospital.MethodsUsing median sagittal T2-weighted images for 16 patients with cervical spinal cord injury without fracture and dislocation who underwent cervical kinematic MRI, the anterior space available for the cord, spinal cord diameter, posterior space available for the cord from C2/3 to C7/T1, and Muhle’s grade were determined. The spinal canal diameter was calculated by adding the anterior space available for the cord, spinal cord diameter, and posterior space available for the cord.ResultsThe anterior space available for the cord, posterior space available for the cord, and spinal canal diameters at C2/3 and C7/T1 were significantly higher than those from C3/4 to C6/7. Muhle’s grades at C2/3 and C7/T1 were significantly lower than those at the other levels. Spinal canal diameter was lower in extension than in the neutral and flexion positions. In the operated segments, significantly lesser space was available for the cord (anterior space available for the cord + posterior space available for the cord), and the spinal cord diameter/spinal canal diameter ratio was higher than those in the C2/3, C7/T1, and non-operated segments.ConclusionKinematic MRI demonstrated dynamic pathoanatomical changes, such as canal stenosis in different positions, in patients with cervical spinal cord injury without fracture and dislocation. The injured segment had a small canal diameter, high Muhle’s grade, low space available for the cord, and high spinal cord diameter/spinal canal diameter ratio.

Cervical kinematic change after posterior full-endoscopic cervical foraminotomy for disc herniation or foraminal stenosis.

Posterior full-endoscopic cervical foraminotomy (PECF) is one of minimally invasive surgical techniques for cervical radiculopathy. Because of minimal disruption of posterior cervical structures, such as facet joint, cervical kinematics was minimally changed. However, a larger resection of facet joint is required for cervical foraminal stenosis (FS) than disc herniation (DH). The objective was to compare the cervical kinematics between patients with FS and DH after PECF. Consecutive 52 patients (DH, 34 vs. FS, 18) who underwent PECF for single-level radiculopathy were retrospectively reviewed. Clinical parameters (neck disability index, neck pain and arm pain), and segmental, cervical and global radiological parameters were compared at postoperative 3, 6, and 12 months, and yearly thereafter. A linear mixed-effect model was used to assess interactions between groups and time. Any occurrence of significant pain during follow-up was recorded during a mean follow-up period of 45.5 months (range 24-113 months). Clinical parameters improved after PECF, with no significant differences between groups. Recurrent pain occurred in 6 patients and surgery (PECF, anterior discectomy and fusion) was performed in 2 patients. Pain-free survival rate was 91% for DH and 83% for FS, with no significant difference between the groups (P = 0.29). Radiological changes were not different between groups (P > 0.05). Segmental neutral and extension curvature became more lordotic. Cervical curvature became more lordotic on neutral and extension X-rays, and the range of cervical motion increased. The mismatch between T1-slope and cervical curvature decreased. Disc height did not change, but the index level showed degeneration at postoperative 2 years. Clinical and radiological outcomes after PECF were not different between DH and FS patients and kinematics were significantly improved. These findings may be informative in a shared decision-making process.

Effect of Muscle Fatigue on the Upper Trapezius Muscle With and Without Myofascial Trigger Points in Students With Neck Pain: A Randomized Controlled Clinical Trial

Objectives: The purpose of this work was to explore cervical position sense and electromyographic (EMG) responses of cervical muscles during head repositioning movements in students with and without upper trapezius muscle trigger points. Materials and Methods: Forty-six right-handed men and women subjects without upper extremity disorders participated in this study. The maximal voluntary contraction (MVC) was measured three time before the fatigue test. A force gauge was used to measure force while recording with a monitor. Measurement was initiated with a MVC force before and after fatigue pain and head positioning were measured. When the protocol was accomplished, the subjects showed signs of exhaustion; however, they were not subjectively evaluated for fatigue. As the protocol aimed at assessing muscle fatigue, a force level of 80% MVC was induced. Results: These findings support the argument that the precision of the neck position sense can be reduced by the fatigue of the neck muscle. Fatigue impaired balance in the trapezius muscles. After removing vision this resulted in an increased center of pressure excursions on a force platform. Motor control did not change significantly in this study. Conclusions: Fatigue had a more significant effect on cervical kinematics in the healthy subjects, probably due to the fact that altered neck motor control in volunteers implied that these individuals were not completely able to make up for fatigue of the neck muscle. Significant pain and head positioning changes were identified following fatigue applied to the pre-determined myofascial trigger points, but the changes were insignificant in the sham control group.

Do the kinematics and sensorimotor control of people with chronic non-specific neck pain differ from those of healthy individuals when assessed in an immersive virtual reality environment? A systematic review

Objective To compare the cervical kinematics and sensorimotor control (i.e., all the afferent, efferent, central integration, and processing components involved in maintaining joint stability) of people with chronic non-specific neck pain (CNSNP) to healthy controls, as assessed in an immersive virtual reality (VR) environment. Methods A comprehensive electronic search was conducted in four databases to identify articles published from inception up until June 2022. The search terms were related to ‘neck pain’ and ‘virtual reality’. Inclusion criteria were observational studies, written in English or French, including a majority of people with CNSNP (≥ 60%), and comparing the cervical kinematics or sensorimotor control between people with CNSNP and healthy controls in an immersive VR environment. Methodological quality was assessed using the Joanna Briggs Institute Critical Appraisal Checklist for Cross-Sectional Studies. The overall certainty of evidence was assessed using the GRADE approach. Results Seven studies were included in the review. A narrative summary of results is provided for each study in relation to the outcomes assessed. Methodological quality was moderate to good. Cervical kinematics seemed to be altered in people with CNSNP compared with healthy controls, except for range of motion and response time. Sensorimotor control assessment showed inconsistent results. The certainty of evidence was very low for both kinematics and sensorimotor control. Conclusion This systematic review provides very low certainty of evidence in favor of different kinematic neck patterns between healthy individuals and people with CNSNP when assessed in an immersive VR environment. No conclusion can be drawn concerning sensorimotor control.

Longitudinal assessment of segmental motion of the cervical spine following total disc arthroplasty: a comparative analysis of devices.

Total disc arthroplasty (TDA) has been shown to be an effective and safe treatment for cervical degenerative disc disease at short- and midterm follow-up. However, there remains a paucity of literature reporting the differences between individual prosthesis designs with regard to device performance. In this study, the authors evaluated the long-term maintenance of segmental range of motion (ROM) at the operative cervical level across a diverse range of TDA devices. In this study, the authors retrospectively evaluated all consecutive patients who underwent 1- or 2-level cervical TDA between 2005 and 2020 at a single institution. Patients with a minimum of 6 months of follow-up and lateral flexion/extension radiographs preoperatively, 2 months postoperatively, and at final follow-up were included. Radiographic measurements included static segmental lordosis, segmental range of motion (ROM) on flexion/extension, global cervical (C2-7) ROM on flexion/extension, and disc space height. The paired t-test was used to evaluate improvement in radiographic parameters. Subanalysis between devices was performed using one-way ANCOVA. Significance was determined at p < 0.05. A total of 85 patients (100 discs) were included, with a mean patient age of 46.01 ± 8.82 years and follow-up of 43.56 ± 39.36 months. Implantations included 22 (22.00%) M6-C, 51 (51.00%) Mobi-C, 14 (14.00%) PCM, and 13 (13.00%) ProDisc-C devices. There were no differences in baseline radiographic parameters between groups. At 2 months postoperatively, PCM provided significantly less segmental lordosis (p = 0.037) and segmental ROM (p = 0.039). At final follow-up, segmental ROM with both the PCM and ProDisc-C devices was significantly less than that with the M6-C and Mobi-C devices (p = 0.015). From preoperatively to 2 months postoperatively, PCM implantation led to a significant loss of lordosis (p < 0.001) and segmental ROM (p = 0.005) relative to the other devices. Moreover, a significantly greater decline in segmental ROM from 2 months postoperatively to final follow-up was seen with ProDisc-C, while segmental ROM increased significantly over time with Mobi-C (p = 0.049). Analysis by TDA device brand demonstrated that motion preservation differs depending on disc design. Certain devices, including M6-C and Mobi-C, improve ROM on flexion/extension from preoperatively to postoperatively and continue to increase slightly at final follow-up. On the other hand, devices such as PCM and ProDisc-C contributed to greater segmental stiffness, with a gradual decline in ROM seen with ProDisc-C. Further studies are needed to understand how much segmental ROM is ideal after TDA for preservation of physiological cervical kinematics.

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

ObjectivesTo 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. MethodsWe 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. ResultsSixty 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. ConclusionsParticipants 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.

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.

Assessment of Neuromuscular and Psychological Function in People with Recurrent Neck Pain during a Period of Remission: Cross-Sectional and Longitudinal Analyses.

The aim of this study was to examine for the presence of differences in neuromuscular and psychological function in individuals with recurrent neck pain (RNP) or chronic neck pain (CNP) following a whiplash trauma compared to healthy controls. A secondary aim was to examine whether neuromuscular characteristics together with psychological features in people with RNP were predictive of future painful episodes. Multiple features were assessed including neck disability, kinesiophobia, quality of life, cervical kinematics, proprioception, activity of superficial neck flexor muscles, maximum neck flexion and extension strength, and perceived exertion during submaximal contractions. Overall, those with RNP (n = 22) and CNP (n = 8) presented with higher neck disability, greater kinesiophobia, lower quality of life, slower and irregular neck movements, and less neck strength compared to controls (n = 15). Prediction analysis in the RNP group revealed that a higher number of previous pain episodes within the last 12 months along with lower neck flexion strength were predictors of higher neck disability at a 6-month follow-up. This preliminary study shows that participants with RNP presented with some degree of altered neuromuscular features and poorer psychological function with respect to healthy controls and these features were similar to those with CNP. Neck flexor weakness was predictive of future neck disability.

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

BackgroundImpaired 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. MethodsCervical 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). FindingsSignificant 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. InterpretationThese 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.