Walid Salem

In vivo three-dimensional kinematics of the cervical spine during maximal axial rotation

The cervical spine exhibits considerable mobility, especially in axial rotation. Axial rotation exerts stress on anatomical structures, such as the vertebral artery which is commonly assessed during clinical examination. The literature is rather sparse concerning the in vivo three-dimensional segmental kinematics of the cervical spine. This study aimed at investigating the three-dimensional kinematics of the cervical spine during maximal passive head rotation with special emphasis on coupled motion. Twenty healthy volunteers participated in this study. Low-dose CT scans were conducted in neutral and in maximum axial rotation positions. Each separated vertebra was segmented semi automatically in these two positions. The finite helical-axis method was used to describe 3D motion between discrete positions. The mean (±SD) maximum magnitude of axial rotation between C0 and C1 was 2.5 ± 1.0° coupled with lateral flexion to the opposite side (5.0 ± 3.0°) and extension (12.0 ± 4.5°). At the C1-C2 level, the mean axial rotation was 37.5 ± 6.0° associated with lateral flexion to the opposite side (2.5 ± 6.0°) and extension (4.0 ± 6.0°). For the lower levels, axial rotation was found to be maximal at C4-C5 level (5.5 ± 1.0°) coupled with lateral flexion to the same side (-4.0 ± 2.5°). Extension was associated at levels C2-C3, C3-C4 and C4-C5, whereas flexion occurred between C5-C6 and C6-C7. Coupled lateral flexion occurred to the opposite side at the upper cervical spine and to the same side at the lower cervical spine.

In vivo 3D kinematics of the cervical spine segments during pre-manipulative positioning at the C4/C5 level.

Segmental range of motion (ROM) during high-velocity manipulative spinal treatment is generally considered an important factor for the risk of adverse side effects, especially in the cervical spine region. Among the many techniques reported, the so-called multiple-component technique (MCT) is increasingly recommended. Such a technique is assumed to induce a relatively low three-dimensional (3D) segmental ROM compared with other techniques. The aims of our study are to quantify the 3D segmental ROM and to determine the pattern of motion between cervical vertebrae during the pre-manipulative position at the C4-C5 level. Ten healthy volunteers participated in this study. Two CT scans were conducted: one in a neutral position and the other in the pre-manipulative positioning. The manipulation using MCT was carried out by a skilled practitioner. During positioning, the head was rotated to the left and bent laterally to the right, and the upper cervical spine was rotated to the left and bent laterally to the right. In contrast, the lower cervical spine underwent right rotation and was bent laterally to the right. Segmental ROM was lower than the values obtained during active physiological rotation (P < 0.05). This study provides new insight into the 3D kinematics of the cervical spine during manipulation. An unexpected mechanism of counter-rotation was identified at the lower cervical levels and could represent a valuable and convenient way for precisely focussing on the level for manipulation.

Sagittal Thoracic and Lumbar Spine Profiles in Upright Standing and Lying Prone Positions Among Healthy Subjects: Influence of Various Biometric Features.

Study Design. A prospective study was performed on the assessment of both thoracic and lumbar spine sagittal profiles (from C7 to S1). Objective. To propose a new noninvasive method for measuring the spine curvatures in standing and lying prone positions and to analyze their relationship with various biometric characteristics. Summary of Background Data. Modifications of spine curvatures (i.e. lordosis or kyphosis) are of importance in the development of spinal disorders. Studies have emphasized the development of new devices to measure the spine sagittal profiles using a noninvasive and low-cost method. To date, it has not been applied for analyzing both lumbar and thoracic alterations for various positioning. Methods. Seventy-five healthy subjects (mean 22.6 ± 4.3 yr) were recruited to participate in this study. Thoracic and lumbar sagittal profiles were assessed in standing and lying prone positions using a 3D digitizer. In addition, several biometric data were collected including maximal trunk isometric strength for flexion and extension movement. Statistical analysis consisted in data comparisons of spine profiles and a multivariate analysis including biometric features, to classify individuals considering low within- and high between-variability. Result. Kyphosis and lordosis angles decreased significantly from standing to lying prone position by an average of 13.4° and 16.6°, respectively. Multivariate analysis showed a sample clustering of 3 homogenous subgroups. The first group displayed larger lordosis and flexibility, and had low data values for height, weight, and strength. The second group had lower values than the overall trend of the whole sample, whereas the third group had larger score values for the torques, height, weight, waist, body mass index, and kyphosis angle but a reduced flexibility. Conclusion. The present results demonstrate a significant effect of the positioning on both thoracic and lumbar spine sagittal profiles and highlight the use of cluster analysis to categorize subgroups after biometric characteristics including curvature measurement. Level of Evidence: N/A

Analysis of the upper cervical spine stiffness during axial rotation: A comparative study among patients with tension-type headache or migraine and asymptomatic subjects

Background: Many studies reported the implication of the cervical musculoskeletal system in patients with tension type headache and migraine. The objective of this study is to investigate the upper cervical spine stiffness features in axial rotation among headache patients in comparison with a healthy population. Methods: 48 subjects including 30 migraine patients with/without aura and 18 patients with tension‐type headache, aged between 18 and 60 years (mean 36, SD 11 years) have been evaluated. Stiffness measurements were carried out for passive axial rotation using a torque meter device. The flexion‐rotation test was used to emphasize assessment of the upper cervical spine. Findings: Neither the stiffness nor the neutral zone varies between different populations studied. Passive range of motion in axial rotation is unilaterally reduced in symptomatic subjects (p = 0.001). Considering the elastic zone, right and left motion magnitude was significantly lower for clinical groups compared to the control group. Interpretation: Stiffness seems not to be altered among tension type headache and migraine patients. However, patients seem prone to display a larger right‐left asymmetry of axial rotation and a reduction in the motion range tolerance, emphasizing the likely link between the cervical discomfort and these pathologies. Any difference is observed in the elastic behavior of the upper cervical spine between the two primary headache populations. However, further investigations are needed to confirm these previous results taking various specific clinical characteristics into consideration. Highlights:Upper cervical spine stiffness was assessed in axial rotation among patients with headache.Range of motion, neutral zone, elastic zone and stiffness was the parameters analyzed.Stiffness and neutral zone were not found to be different compared to asymptomatic subjects.Larger right‐left asymmetry of passive motion magnitude was observed for the clinical groups.This database provides stiffness features of the upper cervical spine among headache patients and asymptomatic subjects.

Morphometric changes of the cervical intervertebral foramen: A comparative analysis of pre-manipulative positioning and physiological axial rotation

BACKGROUND Cervical foraminal impingement has been described as a source of radicular pain. Clinical tests and head motions have been reported for affecting the intervertebral foramen (IVF) dimensions. Although manual approaches are proposed in the management of cervical radiculopathy, their influence on the foraminal dimensions remains unclear. OBJECTIVES To investigate the influence of pre-manipulative positioning versus cervical axial rotation on the foraminal dimensions of the lower cervical spine. METHODS Thirty asymptomatic volunteers underwent CT scan imaging in neutral position and axial rotation or pre-manipulative positioning. The manipulation task was performed at C4-C5 following a multiple components procedure. 3D kinematics and IVF (height, width and area) were computed for each cervical segment. RESULTS The results showed that foraminal changes are dependent on motion types and cervical levels. With reference to head rotation, IVF opening occurred on the ipsilateral side during pre-manipulative positioning while axial rotation involved the contralateral side. Regardless of the side considered, magnitudes of opening were similar between both attitudes while narrowing was lower at the target and adjacent levels during the pre-manipulative positioning. Some associations between segmental motion and IVF changes were observed for the target level and the overlying level. CONCLUSIONS The present study demonstrated that pre-manipulative positioning targeting C4-C5 modified IVF dimensions differently than the passive axial rotation. The findings suggest that techniques which incorporate combined movement positioning influence segmental motion and IVF dimensions differently at the target segment, compared to unconstrained rotation. Further investigations are needed to determine the clinical outcomes of such an approach.

Assessment of cervical stiffness in axial rotation among chronic neck pain patients: A trial in the framework of a non-manipulative osteopathic management

Background Cervical stiffness is a clinical feature commonly appraised during the functional examination of cervical spine. Measurements of cervical stiffness in axial rotation have not been reported for patients with neck pain. The purpose of this study was to investigate cervical spine stiffness in axial rotation among neck pain patients and asymptomatic subjects, and to analyze the impact of osteopathic management. Methods Thirty‐five individuals (17 patients) were enrolled. Measurements were carried out for left‐right axial rotation using a torque meter device, prior and after intervention. Passive range of motion, stiffness, and elastic‐and neutral zone magnitudes were analyzed. Pain intensity was also collected for patients. The intervention consisted in one single session of non‐manipulative osteopathic treatment performed in both groups. Findings A significant main effect of intervention was found for total range of motion and neutral zone. Also, treatment by group interaction was demonstrated for neutral‐, elastic zone, stiffness in right axial rotation, and for total neutral zone. Significant changes were observed in the clinical group after intervention, indicating elastic zone decrease and neutral zone increase. In contrast, no significant alteration was detected for the control group. Interpretations Stiffness characteristics of the cervical spine in axial rotation are prone to be altered in patients with neck pain, but seem to be relieved after a session of non‐manipulative manual therapeutic techniques. Further investigations, including randomized clinical trials with various clinical populations and therapeutic modalities, are needed to confirm these preliminary findings. HighlightsCervical stiffness was tested in axial rotation for neck pain and healthy subjects.Effect of osteopathic non‐manipulative techniques on the stiffness was assessed.Range of motion and neutral zone were altered in patients compared to healthy subjects.Stiffness features and pain were improved for neck pain patientsCervical stiffness in axial rotation could provide relevant clinical information.

Cinématique 3D lors de la manipulation de la colonne vertébrale en ‘rouleau lombaire’, étude préliminaire

L’étude a été réalisée sur un sujet sain de 29 ans (F), consentant. Une première acquisition scanner en position neutre est réalisée avec des coupes jointives de 1.5 mm reconstruites tous les 0.7 mm. Le sujet a ensuite été manipulé en rouleau lombaire (figure 1) puis maintenu par des sangles en position post-manipulative pour une deuxième acquisition scanner. Une segmentation 3D de chaque vertèbre lombaire a été réalisée (figure 1) et trois marqueurs anatomiques non collinaires ont été choisis sur chaque vertèbre dans les deux positions. Le changement des positions a été calculé en appliquant les principes de la cinématique du corps rigide, pour obtenir ainsi la matrice de rotation et le vecteur de translation. A partir de cette matrice de rotation on détermine le vecteur d’orientation qui équivaut à l’axe hélicoı̈dal (Spoor and Veldpaus 1980). Connaissant l’orientation et l’amplitude de rotation autour de cet axe on peut aisément déterminer les angles anatomiques (figure 2).

Analyse de la cinématique 3D du rachis cervical lors de la rotation maximale de la tête

La quantification des amplitudes articulaires in vivo de la colonne vertébrale reste toujours d’actualité, beaucoup de chercheurs se sont penchés sur ce thème soit in vitro soit in vivo. (Ishii 2004) ont développé uneméthode d’analyse 3Dde la colonne cervicale supérieure à partir de l’imageriemédicale. Une dysfonction cervicale peut mener à divers symptômes cliniques diffus. Son objectivation n’a pas encore fait l’objet d’études ou du moins de publications (Maigne 2002). Notre étude pourrait permettre grâce à la mesure des amplitudes articulaires des différents mouvements couplés à définir et à cibler une éventuelle dysfonction vertébrale au sein d’un ou de plusieurs étages cervicaux.