Automated motion analysis of bony joint structures from dynamic computer tomography images: A multi-atlas approach

Dynamic computer tomography (CT) is an emerging modality to analyze in-vivo joint kinematics at the bone level, but it requires manual bone segmentation and, in some instances, landmark identification. The objective of this study is to present an automated workflow for the assessment of three-dimensional in vivo joint kinematics from dynamic musculoskeletal CT images. The proposed method relies on a multi-atlas, multi-label segmentation and landmark propagation framework to extract bony structures and detect anatomical landmarks on the CT dataset. The segmented structures serve as regions of interest for the subsequent motion estimation across the dynamic sequence. The landmarks are propagated across the dynamic sequence for the construction of bone embedded reference frames from which kinematic parameters are estimated. We applied our workflow on dynamic CT images obtained from 15 healthy subjects on two different joints: thumb base (n = 5) and knee (n = 10). The proposed method resulted in segmentation accuracies of 0.90 ± 0.01 for the thumb dataset and 0.94 ± 0.02 for the knee as measured by the Dice score coefficient. In terms of motion estimation, mean differences in cardan angles between the automated algorithm and manual segmentation, and landmark identification performed by an expert were below 1◦. Intraclass correlation (ICC) between cardan angles from the algorithm and results from expert manual landmarks ranged from 0.72 to 0.99 for all joints across all axes. The proposed automated method resulted in reproducible and reliable measurements, enabling the assessment of joint kinematics using 4DCT in clinical routine

Reproducibility of global three-dimensional motion during manual atlanto-axial rotation mobilization: an in vitro study

The reproducibility of the three-dimensional (3D) kinematic aspects of motion coupling patterns during manual mobilizing techniques is still a debatable matter. The present in vitro study analysed segmental 3D motion of the atlanto-axial joint during manual axial rotation mobilization. Twenty fresh frozen human cervical specimens were studied in a test–retest situation with two examiners. The specimens were manually mobilized using three different techniques: (1) a regional mobilization technique of the cervical spine; (2) a segmental mobilization technique of the atlas with manual fixation of the axis; and (3) a segmental mobilization of the atlas on the axis applying a locking technique. Segmental atlanto-axial kinematics was registered with a Zebris CMS-20 ultrasound-based tracking system. The Euclidian norm was used as a representation of overall 3D motion. The results indicated good reproducibility (mean intraclass correlation coefficient, ICC: 0.87). Intraobserver reproducibility was slightly higher (mean ICC: 0.91; range: 0.76–0.99) than interobserver reproducibility (mean ICC: 0.85; range: 0.56–0.98) (P < 0.05). The total range of motion expressed as the Euclidean norm of 3D motion components was a parameter with good reproducibility in the study of segmental kinematics of manual atlanto-axial mobilization. Although previous studies have demonstrated poor inter-rater reliability of manual examination and mobilization of segmental motion components, the results of the present study shed a new and more positive light on the reproducibility of techniques for manual mobilization of the upper cervical spine

Symptom localization tests in the cervical spine: a descriptive study using imaging verification

The concept of isolation of a movement to a single specific spinal segment by blocking/stabilization is considered useful and important during both examination and treatment. This descriptive study endeavoured to determine whether a typical manual stabilizing procedure changes movement patterns in the cervical spine. Lateral radiographs were taken of five volunteers in active/assisted extension with and without manual fixation grasping with the thumb and fingers around the dorsal aspect of the neck at the level of the vertebral arch. Vertebral angular differences between the fixated and non-fixated movements were measured for intra-rater and inter-rater reliability using an intraclass correlation coefficient (ICC) and analyzed for differences using a student t-test. Intraclass correlation coefficient values for intra-rater reliability were fair to moderate whereas inter-rater reliability was excellent. Although not statistically significant, the results showed that in relation to the active extension, the vertebra above the fixated vertebrae moved slightly less (mean = −0.08°; SD = 2.55) as did the vertebrae two levels above fixation (mean = −0.11°; SD = 2.13). Movements of the vertebrae below the fixation and two levels below the fixation were also reduced (mean = −1.09°; SD = 2.07) and (mean = −0.65°; SD = 1.85) respectively. The results suggest the possibility of a three-point bending of the spinal column during fixation and symptom localization during fixation may be a product of soft tissue tension and/or pressure from the fixating fingers. Further research is necessary, including a design that allows consistency among all participants which is appropriately powered

Three-dimensional kinematics of the cervical spine using an electromagnetic tracking device. Differences between healthy subjects and subjects with nonspecific neck pain and the effect of age

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Étude cinématique de l'articulation glénohumérale avec pincement interne en fin de phase préparatoire

Baeyens J.-P., Van Roy P., Cattrysse E., Declercq G., Clarys J.-P. Étude cinématique de l'articulation glénohumérale avec pincement interne en fin de phase préparatoire. In: Les Cahiers de l'INSEP, n°35, 2005. Les sports de raquette. Données scientifiques et méthodologiques. Applications pour l'entraînement. pp. 213-214