A Quantitative Three-dimensional Analysis of Arm Kinematics in Violin Performance

2003 ◽  
Vol 18 (1) ◽  
pp. 3-10 ◽  
Author(s):  
Gongbing Shan ◽  
Peter Visentin

Overuse syndrome (OS) resulting from repetitive motion affects a significant percentage of performing musicians. Particularly susceptible to OS, violinists use different kinds of muscle control patterns in the right and left limbs and must assume a complex asymmetrical posture to hold and play the instrument. There is a clear need for developing efficient and effective strategies to prevent OS in violinists, keeping biological loads under physiological limits and focusing on physical economy during training. The first step in developing such strategies requires quantitative kinematic description of the motions involved in violin performance. This study supplies such information for the arms and violin bow. The motions of eight professional violinists and three advanced university music students were captured using a nine-camera VICON V8i motion capture system. Each performed a fundamental control skill employing all four strings of the violin. The data were analyzed using quantitative model comparison and statistical analysis. The results of this study show parameters such as elbow height normalized by body height and shoulder and elbow joint motion to have highly consistent patterns between the subjects. Wrist control patterns varied widely. Playing on different strings influences right arm patterns significantly, but not left. This is the first study providing quantitative 3-D kinematic data on shoulders, elbows, wrists, and bow. It provides a foundation for further exploration of the kinematic characteristics of violin performance, for the examination of the potential causes of OS, and for an evaluation of practices that might minimize injuries.


2021 ◽  
Vol 15 (2) ◽  
pp. 9-14
Author(s):  
Eliza Smoła ◽  
Katarzyna Wódka ◽  
Marta A. Bibro ◽  
Agnieszka Jankowicz-Szymańska

<p><b>Introduction: </b>The objective of the study was to assess the flexibility of the hamstring muscles and their relationship with the position of the spine, shoulder and pelvic girdles in individual planes in boys training football. <p><b>Material and methods: </b>The study included 28 boys aged 10-14, training football 3 times a week for at least 2 years. The subjects were divided into two groups: correct bilateral flexibility of the hamstring muscles, bilateral shortening of the hamstring muscles. Body height and weight were measured and BMI was calculated. The three-dimensional position of the trunk was examined using the Zebris pointer ultrasound system. The passive straightleg- raising test was used to assess the flexibility of the hamstring muscles. <p><b>Results: </b>32% of people were diagnosed with the correct length of both hamstring muscles, 57% had shortened muscles in both limbs. Mean values determining the depth of thoracic kyphosis indicated its deepening in each of the groups, however, lower values were recorded in boys with reduced flexibility of the hamstring muscle mass. This group was also characterised by a better balance of the trunk in the sagittal plane. The average depth of lumbar lordosis in both groups was within the normal range. In the frontal plane, in both groups of footballers there was a tendency to lift the left shoulder (more frequent in the group with normal flexibility), the pelvis on the left side and shift the trunk to the right. <p><b>Conclusion: </b>Shortening of the hamstring muscles is common in boys who train football, but no evidence of a relationship between the limited flexibility of these muscles and the position of the trunk was found.



Author(s):  
Tatiana Shulga ◽  
Tatiana Shulga ◽  
Leonid Cherkesov ◽  
Leonid Cherkesov

In this work, the waves and currents generated by prognostic wind in the Sea of Azov are investigated using a three-dimensional nonlinear sigma-coordinate model. The mathematical model was also used for studying the transformation of passive admixture in the Sea of Azov, caused by the spatiotemporal variations in the fields of wind and atmospheric pressure, obtained from the prediction SKIRON model. Comparison of the results of numerical calculations and the data of field observations, obtained during the action of the wind on a number of hydrological stations was carried out. The evolutions of storm surges, velocities of currents and the characteristics of the pollution region at different levels of intensity of prognostic wind and stationary currents were found. The results of a comprehensive study allow reliably estimate modern ecological condition of offshore zones, develop predictive models of catastrophic water events and make science-based solutions to minimize the possible damage.



2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Naoki Enomoto ◽  
Kazuhiko Yamada ◽  
Daiki Kato ◽  
Shusuke Yagi ◽  
Hitomi Wake ◽  
...  

Abstract Background Bochdalek hernia is a common congenital diaphragmatic defect that usually manifests with cardiopulmonary insufficiency in neonates. It is very rare in adults, and symptomatic cases are mostly left-sided. Diaphragmatic defects generally warrant immediate surgical intervention to reduce the risk of incarceration or strangulation of the displaced viscera. Case presentation A 47-year-old woman presented with dyspnea on exertion. Computed tomography revealed that a large part of the intestinal loop with superior mesenteric vessels and the right kidney were displaced into the right thoracic cavity. Preoperative three-dimensional (3D) simulation software visualized detailed anatomy of displaced viscera and the precise location and size of the diaphragmatic defect. She underwent elective surgery after concomitant pulmonary hypertension was stabilized preoperatively. The laparotomic approach was adopted. Malformation of the liver and the presence of intestinal malrotation were confirmed during the operation. The distal part of the duodenum, jejunum, ileum, colon, and right kidney were reduced into the abdominal cavity consecutively. A large-sized oval defect was closed with monofilament polypropylene mesh. No complications occurred postoperatively. Conclusion Symptomatic right-sided Bochdalek hernia in adults is exceedingly rare and is frequently accompanied by various visceral anomalies. Accurate diagnosis and appropriate surgical repair are crucial to prevent possible incarceration or strangulation. The preoperative 3D simulation provided comprehensive information on anatomy and concomitant anomalies and helped surgeons plan the operation meticulously and perform procedures safely.



2020 ◽  
Vol 10 (1) ◽  
pp. 14
Author(s):  
Cezary Grochowski ◽  
Kamil Jonak ◽  
Marcin Maciejewski ◽  
Andrzej Stępniewski ◽  
Mansur Rahnama-Hezavah

Purpose: The aim of this study was to assess the volumetry of the hippocampus in the Leber’s hereditary optic neuropathy (LHON) of blind patients. Methods: A total of 25 patients with LHON were randomly included into the study from the national health database. A total of 15 patients were selected according to the inclusion criteria. The submillimeter segmentation of the hippocampus was based on three-dimensional spoiled gradient recalled acquisition in steady state (3D-SPGR) BRAVO 7T magnetic resonance imaging (MRI) protocol. Results: Statistical analysis revealed that compared to healthy controls (HC), LHON subjects had multiple significant differences only in the right hippocampus, including a significantly higher volume of hippocampal tail (p = 0.009), subiculum body (p = 0.018), CA1 body (p = 0.002), hippocampal fissure (p = 0.046), molecular layer hippocampus (HP) body (p = 0.014), CA3 body (p = 0.006), Granule Cell (GC) and Molecular Layer (ML) of the Dentate Gyrus (DG)–GC ML DG body (p = 0.003), CA4 body (p = 0.001), whole hippocampal body (p = 0.018), and the whole hippocampus volume (p = 0.023). Discussion: The ultra-high-field magnetic resonance imaging allowed hippocampus quality visualization and analysis, serving as a powerful in vivo diagnostic tool in the diagnostic process and LHON disease course assessment. The study confirmed previous reports regarding volumetry of hippocampus in blind individuals.



2020 ◽  
Vol 46 (08) ◽  
pp. 895-907
Author(s):  
Nina D. Anfinogenova ◽  
Oksana Y. Vasiltseva ◽  
Alexander V. Vrublevsky ◽  
Irina N. Vorozhtsova ◽  
Sergey V. Popov ◽  
...  

AbstractPrompt diagnosis of pulmonary embolism (PE) remains challenging, which often results in a delayed or inappropriate treatment of this life-threatening condition. Mobile thrombus in the right cardiac chambers is a neglected cause of PE. It poses an immediate risk to life and is associated with an unfavorable outcome and high mortality. Thrombus residing in the right atrial appendage (RAA) is an underestimated cause of PE, especially in patients with atrial fibrillation. This article reviews achievements and challenges of detection and management of the right atrial thrombus with emphasis on RAA thrombus. The capabilities of transthoracic and transesophageal echocardiography and advantages of three-dimensional and two-dimensional echocardiography are reviewed. Strengths of cardiac magnetic resonance imaging (CMR), computed tomography, and cardiac ventriculography are summarized. We suggest that a targeted search for RAA thrombus is necessary in high-risk patients with PE and atrial fibrillation using transesophageal echocardiography and/or CMR when available independently on the duration of the disease. High-risk patients may also benefit from transthoracic echocardiography with right parasternal approach. The examination of high-risk patients should involve compression ultrasonography of lower extremity veins along with the above-mentioned technologies. Algorithms for RAA thrombus risk assessment and protocols aimed at identification of patients with RAA thrombosis, who will potentially benefit from treatment, are warranted. The development of treatment protocols specific for the diverse populations of patients with right cardiac thrombosis is important.



2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Keunbada Son ◽  
Young-Tak Son ◽  
Ji-Min Lee ◽  
Kyu-Bok Lee

AbstractThis study evaluated the marginal and internal fit and intaglio surface trueness of interim crowns fabricated from tooth preparation scanned at four finish line locations. The right maxillary first molar tooth preparation model was fabricated using a ceramic material and placed in four finish line locations (supragingival, equigingival, subgingival, and subgingival with a cord). Intraoral scanning was performed. Crowns were designed based on the scanned area. Interim crowns were fabricated using a stereolithography three-dimensional (3D) printer (N = 16 per location). Marginal and internal fit were evaluated with a silicone replica technique. Intaglio surface trueness was evaluated using a 3D inspection software. One-way analysis of variance and Tukey HSD test were performed for comparisons (α = 0.05). The marginal and internal fit showed significant differences according to locations (P < 0.05); the marginal fit showed the best results in the supragingival finish line (P < 0.05). Intaglio surface trueness was significantly different in the marginal region, with the highest value in the subgingival location (P < 0.05). Crowns fabricated on the subgingival finish line caused inaccurate marginal fit due to poor fabrication reproducibility of the marginal region. The use of an intraoral scanner should be decided on the clinical situation and needs.



Author(s):  
Javier Rolda´n Mckinley ◽  
Carl Crane ◽  
David B. Dooner

This paper introduces a reconfigurable closed-loop spatial mechanism that can be applied to repetitive motion tasks. The concept is to incorporate five pairs of non-circular gears into a six degree-of–freedom closed-loop spatial chain. The gear pairs are designed based on given mechanism parameters and a user defined motion specification of a coupler link of the mechanism. It is shown in the paper that planar gear pairs can be used if the spatial closed-loop chain is comprised of six pairs of parallel joint axes, i.e. the first joint axis is parallel to the second, the third is parallel to the fourth, ..., and the eleventh is parallel to the twelfth. This paper presents the synthesis of the gear pairs that satisfy a specified three-dimensional position and orientation need. Numerical approximations were used in the synthesis the non-circular gear pairs by introducing an auxiliary monotonic parameter associated to each end-effector position to parameterize the motion needs. The findings are supported by a computer animation. No previous known literature incorporates planar non-circular gears to fulfill spatial motion generation needs.



Sign in / Sign up

Export Citation Format

Share Document