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PURPOSE: To assess the test-retest and inter-rater reliability of goniometry and fleximetry in measuring cervical range of motion in individuals with chronic neck pain. METHODS: A reliability study. Thirty individuals with chronic neck pain were selected. Cervical range of motion was measured by goniometry and fleximetry at two time points 7 days apart. To characterize the sample, we used the numerical pain rating scale, Pain-Related Catastrophizing Thoughts Scale, and Neck Disability Index. Intraclass correlation coefficient (ICC), standard error of measurement (SEM) and minimum detectable change (MDC) were calculated. Correlations between goniometry and fleximetry measurements were performed using Spearman's correlation coefficient (rho). RESULTS: For goniometry, we found excellent test-retest reliability (ICC ≥ 0.986, SEM ≤ 1.89%, MDC ≤ 5.23%) and inter-rater reliability (ICC ≥ 0.947, SEM ≤ 3.91%, MDC ≤ 10.84%). Similarly, we found excellent test-retest reliability (ICC ≥ 0.969, SEM ≤ 2.71%, MDC ≤ 7.52%) and inter-rater reliability (ICC ≥ 0.981, SEM ≤ 1.88%, MDC ≤ 5.20%) for fleximetry. Finally, we observed a strong correlation between the goniometry and the fleximetry for all cervical movements (rho ≥ 0.993). CONCLUSION: Goniometry and fleximetry measurements are reliable for assessing cervical range of motion in individuals with chronic neck pain.
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Artrometría Articular , Vértebras Cervicales , Dolor Crónico , Dolor de Cuello , Rango del Movimiento Articular , Humanos , Dolor de Cuello/fisiopatología , Dolor de Cuello/diagnóstico , Rango del Movimiento Articular/fisiología , Femenino , Reproducibilidad de los Resultados , Masculino , Dolor Crónico/fisiopatología , Dolor Crónico/diagnóstico , Artrometría Articular/métodos , Adulto , Persona de Mediana Edad , Vértebras Cervicales/fisiopatología , Dimensión del Dolor/métodos , Variaciones Dependientes del ObservadorRESUMEN
INTRODUCTION: The cervical spine, pivotal for mobility and overall body function, can be affected by cervical spondylosis, a major contributor to neural disorders. Prevalent in both general and military populations, especially among pilots, cervical spondylosis induces pain and limits spinal capabilities. Anterior Cervical Discectomy and Fusion (ACDF) surgery, proposed by Cloward in the 1950s, is a promising solution for restoring natural cervical curvature. The study objective was to investigate the impacts of ACDF implant design on postsurgical cervical biomechanics and neurorehabilitation outcomes by utilizing a biofield head-neck finite element (FE) platform that can facilitate scenario-specific perturbations of neck muscle activations. This study addresses the critical need to enhance computational models, specifically FE modeling, for ACDF implant design. MATERIALS AND METHODS: We utilized a validated head-neck FE model to investigate spine-implant biomechanical interactions. An S-shaped dynamic cage incorporating titanium (Ti) and polyetheretherketone (PEEK) materials was modeled at the C4/C5 level. The loading conditions were carefully designed to mimic helmet-to-helmet impact in American football, providing a realistic and challenging scenario. The analysis included intervertebral joint motion, disk pressure, and implant von Mises stress. RESULTS: The PEEK implant demonstrated an increased motion in flexion and lateral bending at the contiguous spinal (C4/C5) level. In flexion, the Ti implant showed a modest 5% difference under 0% activation conditions, while PEEK exhibited a more substantial 14% difference. In bending, PEEK showed a 24% difference under 0% activation conditions, contrasting with Ti's 17%. The inclusion of the head resulted in an average increase of 18% in neck angle and 14% in C4/C5 angle. Disk pressure was influenced by implant material, muscle activation level, and the presence of the head. Polyetheretherketone exhibited lower stress values at all intervertebral disc levels, with a significant effect at the C6/C7 levels. Muscle activation level significantly influenced disk stress at all levels, with higher activation yielding higher stress. Titanium implant consistently showed higher disk stress values than PEEK, with an orders-of-magnitude difference in von Mises stress. Excluding the head significantly affected disk and implant stress, emphasizing its importance in accurate implant performance simulation. CONCLUSIONS: This study emphasized the use of a biofidelic head-neck model to assess ACDF implant designs. Our results indicated that including neck muscles and head structures improves biomechanical outcome measures. Furthermore, unlike Ti implants, our findings showed that PEEK implants maintain neck motion at the affected level and reduce disk stresses. Practitioners can use this information to enhance postsurgery outcomes and reduce the likelihood of secondary surgeries. Therefore, this study makes an important contribution to computational biomechanics and implant design domains by advancing computational modeling and theoretical knowledge on ACDF-spine interaction dynamics.
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Vértebras Cervicales , Análisis de Elementos Finitos , Humanos , Fenómenos Biomecánicos/fisiología , Vértebras Cervicales/cirugía , Vértebras Cervicales/fisiopatología , Prótesis e Implantes , Fusión Vertebral/métodos , Fusión Vertebral/instrumentación , TitanioRESUMEN
BACKGROUND Cervical spondylosis (CS) is a degenerative disease of the cervical spine characterized by persistent neck pain. Cervical facet joint mobilization (CM) and the osteopathic muscle energy technique (MET) are effective manual procedures for the treatment of neck pain. In this study, we compared the efficacy of the MET and CM techniques on pain, disability, and proprioception in 76 patients with CS. MATERIAL AND METHODS A total of 96 participants with a diagnosis of CS were randomized into an electro-thermal therapy (ET) group (control group, n=32), ET+MET group (experiment I, n=32), and ET+CM group (experiment II, n=32). All patients received 3 treatment sessions per week for 4 consecutive weeks. Pain intensity, functional disability and cervical position sense were measured using the visual analog scale (VAS), Copenhagen Neck Functional Disability Scale (CNFDS), and cervical range of motion (CROM) device. RESULTS The study was completed by 76 participants. VAS and CNFDS scores decreased significantly after treatment in all 3 groups (P<0.001); however, there was no significant difference between the groups (P>0.05). Between-group analysis showed a significant difference in extension joint position error in favor of MET (P<0.001), while there was no significant difference between the groups in other movement directions (P>0.05). CONCLUSIONS MET and CM have similar effects on improving pain and disability in individuals with CS and chronic neck pain. However, the results of this study show that MET combined with ET is a more effective method for improving cervical position sense.
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Vértebras Cervicales , Dolor de Cuello , Dimensión del Dolor , Propiocepción , Rango del Movimiento Articular , Espondilosis , Humanos , Espondilosis/terapia , Espondilosis/fisiopatología , Femenino , Masculino , Persona de Mediana Edad , Dolor de Cuello/terapia , Dolor de Cuello/fisiopatología , Propiocepción/fisiología , Adulto , Dimensión del Dolor/métodos , Vértebras Cervicales/fisiopatología , Resultado del Tratamiento , Osteopatía/métodos , Evaluación de la Discapacidad , Articulación Cigapofisaria/fisiopatologíaRESUMEN
OBJECTIVE: To investigate dizziness, vestibular/oculomotor symptoms, and cervical spine proprioception among adults with/without a concussion history. METHODS: Adults ages 18-40 years with/without a concussion history completed: dizziness handicap inventory (DHI), visio-vestibular exam (VVE), and head repositioning accuracy (HRA, assesses cervical spine proprioception). Linear regression models were used to assess relationships between (1) concussion/no concussion history group and VVE, HRA, and DHI, and (2) DHI with HRA and VVE for the concussion history group. RESULTS: We enrolled 42 participants with concussion history (age = 26.5 ± 4.5 years, 79% female, mean = 1.4± 0.8 years post-concussion) and 46 without (age = 27.0± 3.8 years, 74% female). Concussion history was associated with worse HRA (ß = 1.23, 95% confidence interval [CI]: 0.77, 1.68; p < 0.001), more positive VVE subtests (ß = 3.01, 95%CI: 2.32, 3.70; p < 0.001), and higher DHI scores (ß = 9.79, 95%CI: 6.27, 13.32; p < 0.001) after covariate adjustment. For the concussion history group, number of positive VVE subtests was significantly associated with DHI score (ß = 3.78, 95%CI: 2.30, 5.26; p < 0.001) after covariate adjustment, while HRA error was not (ß = 1.10, 95%CI: -2.32, 4.51; p = 0.52). CONCLUSIONS: Vestibular/oculomotor symptom provocation and cervical spine proprioception impairments may persist chronically (i.e., 3 years) after concussion. Assessing dizziness, vestibular/oculomotor and cervical spine function after concussion may inform patient-specific treatments to address ongoing dysfunction.
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Conmoción Encefálica , Vértebras Cervicales , Mareo , Propiocepción , Humanos , Femenino , Masculino , Propiocepción/fisiología , Adulto , Mareo/fisiopatología , Mareo/etiología , Conmoción Encefálica/fisiopatología , Vértebras Cervicales/lesiones , Vértebras Cervicales/fisiopatología , Adulto Joven , Adolescente , Vestíbulo del Laberinto/fisiopatologíaRESUMEN
Traumatic cervical spinal cord injury (TCSCI) often causes varying degrees of motor dysfunction, common assessed by the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI), in association with the American Spinal Injury Association (ASIA) Impairment Scale. Accurate prediction of motor function recovery is extremely important for formulating effective diagnosis, therapeutic and rehabilitation programs. The aim of this study is to investigate the validity of a novel nested ensemble algorithm that uses the very early ASIA motor score (AMS) of ISNCSCI examination to predict motor function recovery 6 months after injury in TCSCI patients. This retrospective study included complete data of 315 TCSCI patients. The dataset consisting of the first AMS at ≤ 24 h post-injury and follow-up AMS at 6 months post-injury was divided into a training set (80%) and a test set (20%). The nested ensemble algorithm was established in a two-stage manner. Support Vector Classification (SVC), Adaboost, Weak-learner and Dummy were used in the first stage, and Adaboost was selected as second-stage model. The prediction results of the first stage models were uploaded into second-stage model to obtain the final prediction results. The model performance was evaluated using precision, recall, accuracy, F1 score, and confusion matrix. The nested ensemble algorithm was applied to predict motor function recovery of TCSCI, achieving an accuracy of 80.6%, a F1 score of 80.6%, and balancing sensitivity and specificity. The confusion matrix showed few false-negative rate, which has crucial practical implications for prognostic prediction of TCSCI. This novel nested ensemble algorithm, simply based on very early AMS, provides a useful tool for predicting motor function recovery 6 months after TCSCI, which is graded in gradients that progressively improve the accuracy and reliability of the prediction, demonstrating a strong potential of ensemble learning to personalize and optimize the rehabilitation and care of TCSCI patients.
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Algoritmos , Recuperación de la Función , Traumatismos de la Médula Espinal , Humanos , Traumatismos de la Médula Espinal/rehabilitación , Traumatismos de la Médula Espinal/fisiopatología , Traumatismos de la Médula Espinal/diagnóstico , Masculino , Femenino , Adulto , Persona de Mediana Edad , Estudios Retrospectivos , Médula Cervical/lesiones , Médula Cervical/fisiopatología , Anciano , Adulto Joven , Pronóstico , Vértebras Cervicales/lesiones , Vértebras Cervicales/fisiopatologíaRESUMEN
BACKGROUND: Following spinal cord injury (SCI), gait function reaches a post-recovery plateau that depends on the paralysis severity. However, the plateau dynamics during the recovery period are not known. This study aimed to examine the gait function temporal dynamics after traumatic cervical SCI (CSCI) based on paralysis severity. METHODS: This retrospective cohort study included 122 patients with traumatic CSCI admitted to a single specialized facility within 2 weeks after injury. The Walking Index for Spinal Cord Injury II (WISCI II) was estimated at 2 weeks and 2, 4, 6, and 8 months postinjury for each American Spinal Injury Association Impairment Scale (AIS) grade, as determined 2 weeks postinjury. Statistical analysis was performed at 2 weeks to 2 months, 2-4 months, 4-6 months, and 6-8 months, and the time at which no significant difference was observed was considered the time at which the gait function reached a plateau. RESULTS: In the AIS grade A and B groups, no significant differences were observed at any time point, while in the AIS grade C group, the mean WISCI II values continued to significantly increase up to 6 months. In the AIS grade D group, the improvement in gait function was significant during the entire observation period. CONCLUSIONS: The plateau in gait function recovery was reached at 2 weeks postinjury in the AIS grade A and B groups and at 6 months in the AIS grade C group.
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Marcha , Recuperación de la Función , Traumatismos de la Médula Espinal , Humanos , Traumatismos de la Médula Espinal/fisiopatología , Traumatismos de la Médula Espinal/complicaciones , Masculino , Femenino , Estudios Retrospectivos , Persona de Mediana Edad , Adulto , Marcha/fisiología , Factores de Tiempo , Vértebras Cervicales/fisiopatología , Vértebras Cervicales/lesiones , Anciano , Médula Cervical/lesiones , Médula Cervical/fisiopatología , Adulto JovenRESUMEN
OBJECTIVE: To investigate the brain mechanism of non-correspondence between imaging presentations and clinical symptoms in cervical spondylotic myelopathy (CSM) patients and to test the utility of brain imaging biomarkers for predicting prognosis of CSM. METHODS: Forty patients with CSM (22 mild-moderate CSM, 18 severe CSM) and 25 healthy controls (HCs) were recruited for rs-fMRI and cervical spinal cord diffusion tensor imaging (DTI) scans. DTI at the spinal cord (level C2/3) with fractional anisotropy (FA) and degree centrality (DC) were recorded. Then one-way analysis of covariance (ANCOVA) was conducted to detect the group differences in the DC and FA values across the three groups. Pearson correlation analysis was then separately performed between JOA with FA and DC. RESULTS: Among them, degree centrality value of left middle temporal gyrus exhibited a progressive increase in CSM groups compared with HCs, the DC value in severe CSM group was higher compared with mild-moderate CSM group. (P < 0.05), and the DC values of the right superior temporal gyrus and precuneus showed a decrease after increase. Among them, DC values in the area of precuneus in severe CSM group were significantly lower than those in mild-moderate CSM and HCs. (P < 0.05). The fractional anisotropy (FA) values of the level C2/3 showed a progressive decrease in different clinical stages, that severe CSM group was the lowest, significantly lower than those in mild-moderate CSM and HCs (P < 0.05). There was negative correlation between DC value of left middle temporal gyrus and JOA scores (P < 0.001), and the FA values of dorsal column in the level C2/3 positively correlated with the JOA scores (P < 0.001). CONCLUSION: Structural and functional changes have taken place in the cervical spinal cord and brain of CSM patients. The Brain reorganization plays an important role in maintaining the symptoms and signs of CSM, aberrant DC values in the left middle temporal gyrus may be the possible mechanism of inconsistency between imaging findings and clinical symptoms. Degree centrality is a potentially useful prognostic functional biomarker in cervical spondylotic myelopathy.
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Vértebras Cervicales , Imagen de Difusión Tensora , Plasticidad Neuronal , Índice de Severidad de la Enfermedad , Espondilosis , Humanos , Masculino , Femenino , Persona de Mediana Edad , Espondilosis/diagnóstico por imagen , Espondilosis/fisiopatología , Vértebras Cervicales/diagnóstico por imagen , Vértebras Cervicales/fisiopatología , Plasticidad Neuronal/fisiología , Adulto , Imagen por Resonancia Magnética , Anciano , Enfermedades de la Médula Espinal/diagnóstico por imagen , Enfermedades de la Médula Espinal/fisiopatología , Encéfalo/diagnóstico por imagen , Encéfalo/fisiopatología , Encéfalo/patología , Estudios de Casos y Controles , AnisotropíaRESUMEN
PURPOSE: The corpus callosum is crucial for interhemispheric interactions in the motor control of limb functions. Human and animal studies suggested spinal cord pathologies may induce cortical reorganization in sensorimotor areas. We investigate participation of the corpus callosum in executions of a simple motor task in patients with cervical spondylotic myelopathy (CSM) using transcranial magnetic stimulation. METHODS: Twenty patients with CSM with various MRI grades of severity of cord compression were compared with 19 normal controls. Ipsilateral silent period, contralateral silent period, central motor conduction time, and transcallosal conduction time (TCT) were determined. RESULTS: In both upper and lower limbs, TCTs were significantly increased for patients with CSM than normal controls ( p < 0.001 for all), without side-to-side differences. Ipsilateral silent period and contralateral silent period durations were significantly increased bilaterally for upper limbs in comparison to controls ( p < 0.01 for all), without side-to-side differences. There were no significant correlations of TCT with central motor conduction time nor severity of CSM for both upper and lower limbs ( p > 0.05 for all) bilaterally. CONCLUSIONS: Previous transcranial magnetic stimulation studies show increased motor cortex excitability in CSM; hence, increased TCTs observed bilaterally may be a compensatory mechanism for effective unidirectional and uniplanar execution of muscle activation in the distal limb muscles. Lack of correlation of TCTs with severity of CSM or central motor conduction time may be in keeping with a preexistent role of the corpus callosum as a predominantly inhibitory pathway for counteracting redundant movements resulting from increased motor cortex excitability occurring after spinal cord lesions.
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Cuerpo Calloso , Potenciales Evocados Motores , Espondilosis , Estimulación Magnética Transcraneal , Humanos , Cuerpo Calloso/fisiopatología , Cuerpo Calloso/diagnóstico por imagen , Masculino , Femenino , Persona de Mediana Edad , Espondilosis/fisiopatología , Potenciales Evocados Motores/fisiología , Adulto , Anciano , Vértebras Cervicales/fisiopatología , Conducción Nerviosa/fisiología , Enfermedades de la Médula Espinal/fisiopatología , Enfermedades de la Médula Espinal/diagnóstico por imagen , Compresión de la Médula Espinal/fisiopatologíaRESUMEN
Artificial disc replacement (ADR) is a clinical procedure used to diagnose cervical degenerative disc disease, preserving range of motion (ROM) at the fixation level and preventing adjacent segment degeneration (ASD). This study analyzed the biomechanics of ADR by examining range of motion (ROM), stress levels in bone and implants, and strain in the bone-implant interface using multi-scale loadings. The study focused on single- and double-level patients across various loading scales during physiological motions within the cervical spine. Results showed increased ROM in single-level and double-level fixations during physiological loadings, while ROM decreased at the adjacent level of fixation with the intact cervical spine model. The Prodisc-Implant metal endplate experienced a maximum von Mises stress of 432 MPa during axial rotation, confirming the long durability and biomechanical performance of the bone-implant interface.
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Vértebras Cervicales , Análisis de Elementos Finitos , Rango del Movimiento Articular , Reeemplazo Total de Disco , Humanos , Vértebras Cervicales/cirugía , Vértebras Cervicales/fisiopatología , Fenómenos Biomecánicos , Reeemplazo Total de Disco/métodos , Degeneración del Disco Intervertebral/cirugía , Degeneración del Disco Intervertebral/fisiopatología , Disco Intervertebral/cirugía , Disco Intervertebral/fisiopatología , Estrés Mecánico , Diseño de Prótesis , Masculino , Soporte de Peso , AdultoRESUMEN
PURPOSE: This study aims to explore the differences in cervical degeneration between healthy people with and without cervical flexion-relaxation phenomenon (FRP) and to identify whether the disappearance of cervical FRP is related to cervical degeneration. METHODS: According to the flexion relaxation ratio (FRR), healthy subjects were divided into the normal FRP group and the abnormal FRP group. Besides, MRI was used to evaluate the degeneration of the passive subsystem (vertebral body, intervertebral disc, cervical sagittal balance, etc.) and the active subsystem (deep flexors [DEs], deep extensors [DFs], and superficial extensors [SEs]). In addition, the correlation of the FRR with the cervical degeneration score, C2-7Cobb, Borden method, relative total cross-sectional area (rTCSA), relative functional cross-sectional area (rFCSA), and fatty infiltration ratio (FIR) was analyzed. RESULTS: A total of 128 healthy subjects were divided into the normal FRP group (n=52, 40.63%) and the abnormal FRP group (n=76, 59.38%). There were significant differences between the normal FRP group and the abnormal FRP group in the cervical degeneration score (z=-6.819, P<0.001), C2-7Cobb (t=2.994, P=0.004), Borden method (t=2.811, P=0.006), and FIR of DEs (t=-4.322, P<0.001). The FRR was significantly correlated with the cervical degeneration score (r=-0.457, P<0.001), C2-7Cobb (r=0.228, P=0.010), Borden method (r=0.197, P=0.026), and FIR of DEs (r=-0.253, P=0.004). CONCLUSION: The disappearance of cervical FRP is related to cervical degeneration. A new hypothesis mechanism for FRP is proposed. The cervical FRP test is an effective and noninvasive examination for the differential diagnosis of healthy people, people with potential NSNP, and patients with NSNP.
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Vértebras Cervicales , Degeneración del Disco Intervertebral , Rango del Movimiento Articular , Humanos , Masculino , Femenino , Vértebras Cervicales/diagnóstico por imagen , Vértebras Cervicales/fisiopatología , Persona de Mediana Edad , Adulto , Degeneración del Disco Intervertebral/diagnóstico por imagen , Degeneración del Disco Intervertebral/fisiopatología , Rango del Movimiento Articular/fisiología , Imagen por Resonancia Magnética/métodos , AncianoRESUMEN
INTRODUCTION: People with chronic neck pain (CNP) commonly exhibit a range of physical impairments including cervical proprioceptive deficits. Assessing proprioception using a head mounted laser to assess joint position error (JPE) is a reliable and valid measure. However, the responsiveness of this measure has not been assessed. OBJECTIVE: To assess the responsiveness of the measure of cervical JPE after a 4-week home-based neck proprioceptive training intervention in people with CNP. DESIGN: An observational study to assess the responsiveness of the measure of cervical JPE. METHODS: The JPE test was assessed in people with CNP before and after 4 weeks of neck proprioception training. JPE was assessed as participants performed neck joint position sense tests for flexion, extension, right rotation, and left rotation in sitting and standing which were performed in a random order. Both the absolute and constant JPE were assessed. The intervention consisted of neck repositioning exercises as well as movement sense exercises. Cohen's d effect size was used to assess the internal responsiveness of the JPE test. The Pearson's correlation was used to assess the change of scores of the laser pointer and measures from inertial measurement units (IMUs) (external responsiveness). RESULTS: After 4 weeks of proprioception training, JPE assessed in sitting reduced from 2.69â¦-3.57⦠to 1.88â¦-1.98⦠for flexion, extension, and right rotation with large effect sizes (Cohen's d range: 1.25-2.00). For left rotation, JPE reduced from 3.23⦠to 1.9â¦, and the effect size was close to being large (Cohen's d: 0.79). When assessed in standing, JPE reduced from 3.49â¦-4.52⦠to 1.5â¦-2.33⦠with large effect sizes (Cohen's d range: 0.89-1.25) for flexion, extension, right rotation, and left rotation. Large effect sizes were not observed for the constant JPE when assessed in either sitting or standing. The assessment of the external responsiveness revealed weak correlations between the change of scores obtained from the laser pointer and the IMUs for all movements, apart from the constant JPE in sitting for left rotation, which showed a strong correlation (r = 0.7). CONCLUSION: The results of this study showed that the measure of the JPE has sufficient internal responsiveness, however, the external responsiveness was inadequate. Further research is advised.
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Dolor de Cuello , Propiocepción , Humanos , Propiocepción/fisiología , Femenino , Masculino , Adulto , Dolor de Cuello/fisiopatología , Dolor de Cuello/terapia , Persona de Mediana Edad , Terapia por Ejercicio/métodos , Rango del Movimiento Articular/fisiología , Cuello/fisiología , Cuello/fisiopatología , Vértebras Cervicales/fisiopatologíaRESUMEN
OBJECTIVES: The traditional understanding of craniocervical alignment emphasizes specific anatomical landmarks. However, recent research has challenged the reliance on forward head posture as the primary diagnostic criterion for neck pain. An advanced relationship exists between neck pain and craniocervical alignment, which requires a deeper exploration of diverse postures and movement patterns using advanced techniques, such as clustering analysis. We aimed to explore the complex relationship between craniocervical alignment, and neck pain and to categorize alignment patterns in individuals with nonspecific neck pain using the K-means algorithm. METHODS: This study included 229 office workers with nonspecific neck pain who applied unsupervised machine learning techniques. The craniocervical angles (CCA) during rest, protraction, and retraction were measured using two-dimensional video analysis, and neck pain severity was assessed using the Northwick Park Neck Pain Questionnaire (NPQ). CCA during sitting upright in a comfortable position was assessed to evaluate the resting CCA. The average of midpoints between repeated protraction and retraction measures was considered as the midpoint CCA. The K-means algorithm helped categorize participants into alignment clusters based on age, sex and CCA data. RESULTS: We found no significant correlation between NPQ scores and CCA data, challenging the traditional understanding of neck pain and alignment. We observed a significant difference in age (F = 140.14, p < 0.001), NPQ total score (F = 115.83, p < 0.001), resting CCA (F = 79.22, p < 0.001), CCA during protraction (F = 33.98, p < 0.001), CCA during retraction (F = 40.40, p < 0.001), and midpoint CCA (F = 66.92, p < 0.001) among the three clusters and healthy controls. Cluster 1 was characterized by the lowest resting and midpoint CCA, and CCA during pro- and -retraction, indicating a significant forward head posture and a pattern of retraction restriction. Cluster 2, the oldest group, showed CCA measurements similar to healthy controls, yet reported the highest NPQ scores. Cluster 3 exhibited the highest CCA during protraction and retraction, suggesting a limitation in protraction movement. DISCUSSION: Analyzing 229 office workers, three distinct alignment patterns were identified, each with unique postural characteristics; therefore, treatments addressing posture should be individualized and not generalized across the population.
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Dolor de Cuello , Postura , Aprendizaje Automático no Supervisado , Humanos , Dolor de Cuello/fisiopatología , Masculino , Femenino , Adulto , Postura/fisiología , Persona de Mediana Edad , Análisis por Conglomerados , Cabeza , Vértebras Cervicales/fisiopatología , Vértebras Cervicales/diagnóstico por imagen , Movimiento/fisiología , Dimensión del Dolor/métodos , Adulto Joven , Movimientos de la Cabeza/fisiologíaRESUMEN
OBJECTIVE: Muscle dysfunction caused by repetitive work or strain in the neck region can interfere muscle responses. Muscle dysfunction can be an important factor in causing cervical spondylosis. However, there has been no research on how the biomechanical properties of the upper cervical spine change when the suboccipital muscle group experiences dysfunction. The objective of this study was to investigate the biomechanical evidence for cervical spondylosis by utilizing the finite element (FE) approach, thus and to provide guidance for clinicians performing acupoint therapy. METHODS: By varying the elastic modulus of the suboccipital muscle, the four FE models of C0-C3 motion segments were reconstructed under the conditions of normal muscle function and muscle dysfunction. For the two normal condition FE models, the elastic modulus for suboccipital muscles on both sides of the C0-C3 motion segments was equal and within the normal range In one muscle dysfunction FE model, the elastic modulus on both sides was equal and greater than 37 kPa, which represented muscle hypertonia; in the other, the elastic modulus of the left and right suboccipital muscles was different, indicating muscle imbalance. The biomechanical behavior of the lateral atlantoaxial joint (LAAJ), atlanto-odontoid joint (ADJ), and intervertebral disc (IVD) was analyzed by simulations, which were carried out under the six loadings of flexion, extension, left and right lateral bending, left and right axial rotation. RESULTS: Under flexion, the maximum stress in LAAJ with muscle imbalance was higher than that with normal muscle and hypertonia, while the maximum stress in IVD in the hypertonic model was higher than that in the normal and imbalance models. The maximum stress in ADJ was the largest under extension among all loadings for all models. Muscle imbalance and hypertonia did not cause overstress and stress distribution abnormalities in ADJ. CONCLUSION: Muscle dysfunction increases the stress in LAAJ and in IVD, but it does not affect ADJ.
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Vértebras Cervicales , Análisis de Elementos Finitos , Humanos , Fenómenos Biomecánicos , Vértebras Cervicales/fisiopatología , Espondilosis/fisiopatología , Músculos del Cuello/fisiopatología , Módulo de Elasticidad , Rango del Movimiento Articular/fisiología , Articulación Atlantoaxoidea/fisiopatología , Hipertonía Muscular/fisiopatología , Hipertonía Muscular/etiologíaRESUMEN
INTRODUCTION/BACKGROUND: Neck pain is a burdensome condition associated with pain, disability, and economic cost. Neck pain has been associated with observable changes in neuromuscular function and biomechanics. Prior research shows impairments in kinematic control, including reduced mobility, velocity, and smoothness of cervical motion. However, the strength of association between these impairments and patient-reported pain and disability is unclear rendering development of novel and relevant rehabilitation strategies difficult. The aim of this systematic review is to synthesize existing evidence on the strength of association between clinical biomechanical metrics of neck function (ROM, strength, acceleration, accuracy, smoothness, etc.) and patient-reported neck pain and disability. METHODS/ANALYSIS: This protocol follows Cochrane guidelines and adheres to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA-P). MEDLINE, EMBASE, CINAHL, SPORTDiscus, Web of Science and Scopus will be searched, along with the gray literature, up to 20 November 2023, using terms and keywords derived from initial scoping searches. Observational studies, including cohorts and cross-sectional studies, that explore associations between clinical biomechanics of the neck and patient-reported outcomes of neck pain or disability will be included. Two reviewers will independently perform study selection, data extraction, and risk of bias assessment (National Institute of Health tool). Data will be synthesized using either a random effects meta-analytic approach or qualitatively using a modified Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach, dependent on the homogeneity of data available. DISCUSSION AND RELEVANCE: This review addresses a gap in the literature by systematically synthesizing findings on the relationship between neck function impairments and patient-reported outcomes. It will identify priorities for neck pain rehabilitation and gaps in current knowledge. DISSEMINATION: The results of this review will be disseminated through a peer-reviewed publication, conference presentation, and lay language summaries posted on an open-access website. TRIAL REGISTRATION: PROSPERO Registration number: CRD42023417317. https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023417317.
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Vértebras Cervicales , Metaanálisis como Asunto , Dolor de Cuello , Revisiones Sistemáticas como Asunto , Humanos , Dolor de Cuello/fisiopatología , Vértebras Cervicales/fisiopatología , Fenómenos Biomecánicos , Rango del Movimiento ArticularRESUMEN
INTRODUCTION: Cervical kinesthesia is an important part of movement control and of great importance for daily function. Previous research on kinesthesia in whiplash-associated disorders (WAD) has focused on grades I-II. More research is needed on WAD grade III. The aim of this study was to investigate cervical kinesthesia in individuals with WAD grades II-III before and after a neck-specific exercise intervention and compare them to healthy controls. METHODS: A prospective, case-control study with a treatment arm (n = 30) and a healthy control arm (n = 30) was conducted in Sweden. The WAD group received a neck-specific exercise program for 12 weeks. The primary outcome to evaluate kinesthesia was neck movement control (the Fly test). Secondary outcomes were neck disability, dizziness and neck pain intensity before and after the Fly test. Outcomes were measured at baseline and post-treatment. The control arm underwent measurements at baseline except for the dizziness questionnaire. A linear mixed model was used to evaluate difference between groups (WAD and control) and over time, with difficulty level in the Fly test and gender as factors. RESULTS: Between-group analysis showed statistically significant differences in three out of five kinesthetic metrics (p = 0.002 to 0.008), but not for the WAD-group follow-up versus healthy control baseline measurements. Results showed significant improvements for the WAD-group over time for three out of five kinaesthesia metrics (p < 0.001 to 0.008) and for neck disability (p < 0.001) and pain (p = 0.005), but not for dizziness (p = 0.70). CONCLUSIONS: The exercise program shows promising results in improving kinesthesia and reducing neck pain and disability in the chronic WAD phase. Future research might benefit from focusing on adding kinesthetic exercises to the exercise protocol and evaluating its beneficial effects on dizziness or further improvement in kinesthesia. IMPACT STATEMENT: Kinesthesia can be improved in chronic WAD patients without the use of specific kinesthetic exercises. TRIAL REGISTRATION: ClinicalTrials.gov (NCT03664934), first registration approved 11/09/2018.
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Terapia por Ejercicio , Cinestesia , Lesiones por Latigazo Cervical , Humanos , Femenino , Masculino , Lesiones por Latigazo Cervical/terapia , Lesiones por Latigazo Cervical/fisiopatología , Lesiones por Latigazo Cervical/complicaciones , Adulto , Estudios de Casos y Controles , Estudios Prospectivos , Cinestesia/fisiología , Terapia por Ejercicio/métodos , Persona de Mediana Edad , Resultado del Tratamiento , Dolor de Cuello/terapia , Dolor de Cuello/etiología , Enfermedad Crónica , Suecia , Vértebras Cervicales/fisiopatologíaRESUMEN
OBJECTIVE: The authors present a finite element analysis (FEA) evaluating the mechanical impact of C1-2 hypermobility on the spinal cord. METHODS: The Code_Aster program was used to perform an FEA to determine the mechanical impact of C1-2 hypermobility on the spinal cord. Normative values of Young's modulus were applied to the various components of the model, including bone, ligaments, and gray and white matter. Two models were created: 25° and 50° of C1-on-C2 rotation, and 2.5 and 5 mm of C1-on-C2 lateral translation. Maximum von Mises stress (VMS) throughout the cervicomedullary junction was calculated and analyzed. RESULTS: The FEA model of 2.5 mm lateral translation of C1 on C2 revealed maximum VMS for gray and white matter of 0.041 and 0.097 MPa, respectively. In the 5-mm translation model, the maximum VMS for gray and white matter was 0.069 and 0.162 MPa. The FEA model of 25° of C1-on-C2 rotation revealed maximum VMS for gray and white matter of 0.052 and 0.123 MPa. In the 50° rotation model, the maximum VMS for gray and white matter was 0.113 and 0.264 MPa. CONCLUSIONS: This FEA revealed significant spinal cord stress during pathological rotation (50°) and lateral translation (5 mm) consistent with values found during severe spinal cord compression and in patients with myelopathy. While this finite element model requires oversimplification of the atlantoaxial joint, the study provides biomechanical evidence that hypermobility within the C1-2 joint leads to pathological spinal cord stress.
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Análisis de Elementos Finitos , Inestabilidad de la Articulación , Médula Espinal , Humanos , Médula Espinal/fisiopatología , Inestabilidad de la Articulación/fisiopatología , Articulación Atlantoaxoidea/fisiopatología , Fenómenos Biomecánicos/fisiología , Vértebras Cervicales/fisiopatología , Estrés Mecánico , Sustancia Blanca/fisiopatología , Sustancia Blanca/diagnóstico por imagen , Rotación , Módulo de ElasticidadRESUMEN
STUDY DESIGN: Clinical experimental diagnostic study. OBJECTIVE: The objective of the study was to investigate cervical spine dynamics including changes in the cervical foramina in patients experiencing intermittent arm radiculopathy. BACKGROUND: Cervical foraminal stenosis is a frequent cause of radicular arm pain. The Spurling test, while specific, lacks the precision to identify symptomatic nerve roots. The relationship among vertebral motion, foraminal changes, and radiculopathy during a Spurling test remains underexplored. PATIENTS AND METHODS: Ten patients with positive Spurling tests and magnetic resonance imaging (MRI) confirmed 1 or 2-level cervical foraminal stenosis were scanned using the Dynamic MRI Compression System enabling a simulated Spurling test inside the MRI gantry of a 3T MRI scanner with a dedicated neck coil. First, a relaxed image acquisition was undertaken, followed by slowly applying the Spurling test until the patient reported aggravation of radiculopathy or discomfort, where the next image series was taken. Zero echo time MRI was employed to obtain computed tomography (CT)-like images. The images were thereafter analyzed using the Sectra® CT-based Micromotion Analysis software for motion analysis. RESULTS: The C4/C5 level exhibited the most significant movements both in translation and rotation, with less movements observed in C5 to C6 and C6 to C7 levels. No uniform pattern emerged that differentiated suspected stenotic levels from nonsuspected levels. Despite relatively small vertebral movements, 9/10 of patients reported arm pain during provocation, indicating extremely narrow margins of tolerance. CONCLUSION: This study demonstrates the utility of zero echo time MRI and CT-based Micromotion Analysis in detecting subtle yet clinically relevant vertebral motions influencing the foramina in the cervical spine during the Spurling maneuver. These findings could lead to a better understanding and potentially improved diagnostic strategies for cervical foraminal stenosis, although further research with a larger cohort is necessary to confirm these results.
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Vértebras Cervicales , Imagen por Resonancia Magnética , Radiculopatía , Tomografía Computarizada por Rayos X , Humanos , Vértebras Cervicales/diagnóstico por imagen , Vértebras Cervicales/fisiopatología , Imagen por Resonancia Magnética/métodos , Masculino , Femenino , Persona de Mediana Edad , Radiculopatía/diagnóstico por imagen , Radiculopatía/fisiopatología , Anciano , Tomografía Computarizada por Rayos X/métodos , Adulto , Estenosis Espinal/diagnóstico por imagen , Estenosis Espinal/fisiopatología , Rango del Movimiento Articular/fisiología , Movimiento/fisiologíaRESUMEN
BACKGROUND: Cervical sagittal alignment is crucial for distributing the head load to lower cervical segments and maintaining normal cervical spine function, but its biomechanical effect on the cervical spine was not fully elucidated. OBJECTIVE: To investigate the effect of cervical sagittal alignment on dynamic intervertebral kinematics. DESIGN: Cross-sectional study. METHODS: Healthy participants without neck pain were recruited and divided into lordosis, straight and kyphosis groups according to the C2-C7 Cobb angle at the neutral position. The anti-directional and total joint motions were extracted across 10 epochs of dynamic cervical flexion and extension movements. RESULTS: /findings: The overall anti-directional joint motion during flexion is larger in the kyphosis group when compared with the lordosis group (p = 0.021), while the range of flexion is smaller in the kyphosis group than that in the lordosis group (p = 0.017). The C2/C3 anti-directional joint motion during extension in the straight group is larger than that in the lordosis group (p = 0016). The range of extension in the kyphosis group (p < 0.001) and the straight group (p = 0.002) are larger than that in the lordosis group. The increased range of extension in the kyphosis and straight groups were mainly from the C3/C4, C4/C5, and C5/C6 joints(p < 0.05). CONCLUSION: Changes in cervical sagittal alignment alter both the quality and quantity of the individual joint motions. More adjustments are required by the cervical joints to complete neck movements with the loss of lordosis. The lordotic curvature is a relatively effort-saving mode for the cervical spine from a biomechanical perspective.
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Vértebras Cervicales , Cifosis , Lordosis , Rango del Movimiento Articular , Humanos , Vértebras Cervicales/fisiopatología , Vértebras Cervicales/diagnóstico por imagen , Masculino , Estudios Transversales , Femenino , Fenómenos Biomecánicos , Adulto , Lordosis/fisiopatología , Lordosis/diagnóstico por imagen , Rango del Movimiento Articular/fisiología , Cifosis/fisiopatología , Cifosis/diagnóstico por imagen , Fluoroscopía/métodos , Voluntarios Sanos , Adulto JovenRESUMEN
Clinical management of whiplash-associated disorders is challenging and often unsuccessful, with over a third of whiplash injuries progressing to chronic neck pain. Previous imaging studies have identified muscle fat infiltration, indicative of muscle weakness, in the deep cervical extensor muscles (multifidus and semispinalis cervicis). Yet, kinematic and muscle redundancy prevent the direct assessment of individual neck muscle strength, making it difficult to determine the role of these muscles in motor dysfunction. The purpose of this study was to determine the effects of deep cervical extensor muscle weakness on multi-directional neck strength and muscle activation patterns. Maximum isometric forces and associated muscle activation patterns were computed in 25 test directions using a 3-joint, 24-muscle musculoskeletal model of the head and neck. The computational approach accounts for differential torques about the upper and lower cervical spine. To facilitate clinical translation, the test directions were selected based on locations where resistance could realistically be applied to the head during clinical strength assessments. Simulation results reveal that the deep cervical extensor muscles are active and contribute to neck strength in directions with an extension component. Weakness of this muscle group leads to complex compensatory muscle activation patterns characterized primarily by increased activation of the superficial extensors and deep upper cervical flexors, and decreased activation of the deep upper cervical extensors. These results provide a biomechanistic explanation for movement dysfunction that can be used to develop targeted diagnostics and treatments for chronic neck pain in whiplash-associated disorders.
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Contracción Isométrica , Fuerza Muscular , Músculos del Cuello , Humanos , Músculos del Cuello/fisiología , Músculos del Cuello/fisiopatología , Fuerza Muscular/fisiología , Contracción Isométrica/fisiología , Lesiones por Latigazo Cervical/fisiopatología , Modelos Biológicos , Fenómenos Biomecánicos , Dolor de Cuello/fisiopatología , Cuello/fisiopatología , Cuello/fisiología , Vértebras Cervicales/fisiopatología , Vértebras Cervicales/fisiología , Femenino , Simulación por Computador , Debilidad Muscular/fisiopatologíaRESUMEN
OBJECTIVE: Corticospinal inhibitory mechanisms are relevant to functional recovery but remain poorly understood after spinal cord injury (SCI). Post-injury characteristics of contralateral silent period (CSP), a measure of corticospinal inhibition evaluated using transcranial magnetic stimulation (TMS), is inconsistent in literature. We envisioned that investigating CSP across muscles with varying degrees of weakness may be a reasonable approach to resolve inconsistencies and elucidate the relevance of corticospinal inhibition for upper extremity function following SCI. METHODS: We studied 27 adults with chronic C1-C8 SCI (age 48.8 ± 16.1 years, 3 females) and 16 able-bodied participants (age 33.2 ± 11.8 years, 9 females). CSP characteristics were assessed across biceps (muscle power = 3-5) and triceps (muscle power = 1-3) representing stronger and weaker muscles, respectively. We assessed functional abilities using the Capabilities of the Upper Extremity Test (CUE-T). RESULTS: Participants with chronic SCI had prolonged CSPs for biceps but delayed and diminished CSPs for triceps compared to able-bodied participants. Early-onset CSPs for biceps and longer, deeper CSPs for triceps correlated with better CUE-T scores. CONCLUSIONS: Corticospinal inhibition is pronounced for stronger biceps but diminished for weaker triceps muscle in SCI indicating innervation relative to the level of injury matters in the study of CSP. SIGNIFICANCE: Nevertheless, corticospinal inhibition or CSP holds relevance for upper extremity function following SCI.