scholarly journals Dynamic motion analysis of snowboard turns by the measurement of motion and reaction force from snow surface

2012 ◽  
Vol 34 ◽  
pp. 754-759 ◽  
Author(s):  
Kiyoshi Hirose ◽  
Hitoshi Doki ◽  
Akiko Kondo
Keyword(s):  
Motion Analysis ◽  
Reaction Force ◽  
Snow Surface ◽  
Dynamic Motion

A-5 A study on motion analysis of carving turns in snowboarding by measurement of reaction force from snow surface

2015 ◽  
Vol 2015 (0) ◽  
pp. _A-5-1_-_A-5-6_
Author(s):  
Haruka CHIBA ◽  
Kiyoshi HIROSE ◽  
Akiko KONDO ◽  
Ayuko SAITO ◽  
Chikako FUSHIMI ◽  
...  
Keyword(s):  
Motion Analysis ◽  
Reaction Force ◽  
Snow Surface

scholarly journals A Study on Motion Analysis of Carving Turns in Snowboarding by Measurement of Reaction Force from Snow Surface

2016 ◽  
Vol 26 (2) ◽  
pp. 2_233-2_242
Author(s):  
Kiyoshi HIROSE ◽  
Haruka CHIBA ◽  
Akiko KONDO ◽  
Ayuko SAITO ◽  
Chikako FUSHIMI ◽  
...  
Keyword(s):  
Motion Analysis ◽  
Reaction Force ◽  
Snow Surface

scholarly journals On the Moving Trajectory of a Ball in a Viscous Liquid between Two Concentric Rigid Spheres

2018 ◽  
Vol 23 (4) ◽  
pp. 77
Author(s):  
Sergey Gladkov ◽  
Sophie Bogdanova
Keyword(s):  
Differential Equations ◽  
Coordinate System ◽  
Viscous Liquid ◽  
Nonlinear Differential Equations ◽  
Reaction Force ◽  
Arbitrary Point ◽  
System Of Equations ◽  
Rigid Spheres ◽  
Dynamic Motion ◽  
Concentric Spheres

In the paper, the dynamic motion of a point ball with a mass of m , sliding in a viscous liquid between two concentric spheres under the influence of gravity and viscous and dry resistance, is investigated. In addition, it is considered that the ball starts its motion from some arbitrary point M 0 = M ( θ 0 , φ 0 ) . A system of nonlinear differential equations in a spheroidal coordinate system is obtained for the angular variables θ and φ to account for all the forces acting on the ball. The dependence of the reaction force on the angular variables is found, and the solution of the resulting system of equations is numerically analyzed. The projections of the trajectories on the plane x − y ,   y − z ,   x − z are found.

scholarly journals Impact of dynamic alignment, motion, and center of rotation on myelopathy grade and regional disability in cervical spondylotic myelopathy

2015 ◽  
Vol 23 (6) ◽  
pp. 690-700 ◽  
Author(s):  
Shian Liu ◽  
Renaud Lafage ◽  
Justin S. Smith ◽  
Themistocles S. Protopsaltis ◽  
Virginie C. Lafage ◽  
...  
Keyword(s):  
Range Of Motion ◽  
Motion Analysis ◽  
Cervical Spondylotic Myelopathy ◽  
Dynamic Motion ◽  
Sf 36 ◽  
Flexion Extension ◽  
Focal Parameters ◽  
The Mean ◽  
Neck Disability ◽  
Flexion And Extension

OBJECT Cervical stenosis is a defining feature of cervical spondylotic myelopathy (CSM). Matsunaga et al. proposed that elements of stenosis are both static and dynamic, where the dynamic elements magnify the canal deformation of the static state. For the current study, the authors hypothesized that dynamic changes may be associated with myelopathy severity and neck disability. This goal of this study was to present novel methods of dynamic motion analysis in CSM. METHODS A post hoc analysis was performed of a prospective, multicenter database of patients with CSM from the AOSpine North American study. One hundred ten patients (34%) met inclusion criteria, which were symptomatic CSM, age over 18 years, baseline flexion/extension radiographs, and health-related quality of life (HRQOL) questionnaires (modified Japanese Orthopaedic Association [mJOA] score, Neck Disability Index [NDI], the 36-Item Short Form Health Survey Physical Component Score [SF-36 PCS], and Nurick grade). The mean age was 56.9 ± 12 years, and 42% of patients were women (n = 46). Correlations with HRQOL measures were analyzed for regional (cervical lordosis and cervical sagittal vertical axis) and focal parameters (kyphosis and spondylolisthesis between adjacent vertebrae) in flexion and extension. Baseline dynamic parameters (flexion/extension cone relative to a fixed C-7, center of rotation [COR], and range of motion arc relative to the COR) were also analyzed for correlations with HRQOL measures. RESULTS At baseline, the mean HRQOL measures demonstrated disability and the mean radiographic parameters demonstrated sagittal malalignment. Among regional parameters, there was a significant correlation between decreased neck flexion (increased C2–7 angle in flexion) and worse Nurick grade (R = 0.189, p = 0.048), with no significant correlations in extension. Focal parameters, including increased C-7 sagittal translation overT-1 (slip), were significantly correlated with greater myelopathy severity (mJOA score, Flexion R = −0.377, p = 0.003; mJOA score, Extension R = −0.261, p = 0.027). Sagittal slip at C-2 and C-4 also correlated with worse HRQOL measures. Reduced flexion/extension motion cones, a more posterior COR, and smaller range of motion correlated with worse general health SF-36 PCS and Nurick grade. CONCLUSIONS Dynamic motion analysis may play an important role in understanding CSM. Focal parameters demonstrated a significant correlation with worse HRQOL measures, especially increased C-7 sagittal slip in flexion and extension. Novel methods of motion analysis demonstrating reduced motion cones correlated with worse myelopathy grades. More posterior COR and smaller range of motion were both correlated with worse general health scores (SF-36 PCS and Nurick grade). To our knowledge, this is the first study to demonstrate correlation of dynamic motion and listhesis with disability and myelopathy in CSM.

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