Gongbing Shan

Full-body kinematic characteristics of the maximal instep soccer kick by male soccer players and parameters related to kick quality.

Many studies try to understand fundamental soccer skills, most focusing on kicking. However, a full picture of an efficient kick remains incomplete owing to constraints of test designs and difficulties that arise in synchronizing and analyzing information generated by multiple assessment techniques. Previous scientific studies may be generally categorized as: two-dimensional kinematic analysis using high-speed cameras, muscle activity studies using electromyography, three-dimensional analysis of the kicking-leg using a partial-body model, and kinetic studies using force measurements and modelling. No existing inquiries have used full-body three-dimensional motion capture and modelling to examine kicking. The current study remedies this deficiency and defines a full-body model capable of revealing more detailed characteristics of kicking. Additionally, it reveals effects of long-term training by comparing novices with skilled athletes and explores new parameters that have potential to aid quantitative evaluations of skill. Results show effective upper-body movement to be a key factor in creating better initial conditions for a more explosive muscle contraction during kicking. It permits a more powerful quasi whip-like movement of the kicking leg. Finally, the timely change of distance between the kick-side hip and the non-kick-side shoulder provides a quantitative means of measuring kick quality.Abstract Many studies try to understand fundamental soccer skills, most focusing on kicking. However, a full picture of an efficient kick remains incomplete owing to constraints of test designs and difficulties that arise in synchronizing and analyzing information generated by multiple assessment techniques. Previous scientific studies may be generally categorized as: two‐dimensional kinematic analysis using high‐speed cameras, muscle activity studies using electromyog‐raphy, three‐dimensional analysis of the kicking‐leg using a partial‐body model, and kinetic studies using force measurements and modelling. No existing inquiries have used full‐body three‐dimensional motion capture and modelling to examine kicking. The current study remedies this deficiency and defines a full‐body model capable of revealing more detailed characteristics of kicking. Additionally, it reveals effects of long‐term training by comparing novices with skilled athletes and explores new parameters that have potential to aid quantitative evaluations of skill. Results show effective upper‐body movement to be a key factor in creating better initial conditions for a more explosive muscle contraction during kicking. It permits a more powerful quasi whip‐like movement of the kicking leg. Finally, the timely change of distance between the kick‐side hip and the non‐kick‐side shoulder provides a quantitative means of measuring kick quality.

Anthropometrical data and coefficients of regression related to gender and race

As a result of migration and globalization, the requirement for anthropometrical data of distinct races and gender has augmented whilst the availability remained minimal. Therefore, several sets of estimation equations, which depend on gender, race, body height (BH), and body mass (BM), were established in this study to fulfill this necessity. The method consisted of: (a) an inexpensive device to scan the body surface, (b) the electronic reconstruction of the body surface and (c) a module to calculate segmental lengths, segmental masses, radii of gyration and moments of inertia, using the 16-segment model (Zatsiorsky, 1983) and density data of Dempster (Space requirements of the seated operator, WADC Technical Report, Wright-Patterson Air Force Base, Ohio, 1995, pp. 55-159), and (d) the establishment of regression equations. One hundred young Chinese and Germans, representing the Asian and Caucasian races, were randomly recruited to participate in this study. The results revealed contrasting trunk, limb lengths and relative skull volume (skull volume/body volume) between the two races as well as the independence of head mass from body height. The regression equations, which were successfully derived based on the above-unveiled differences, are capable of supplying a prompt way to obtain all anthropometrical parameters of different genders and race groups through individual BM and BH. Anthropometrical data are related to gender, race, BH and BM. In order to obtain the data, one can utilize various measurements, which might have enormous financial expenditure in addition to time-consumption or employ the convenient and economical short-cut-regression-to obtain such data. The results of this study reveal that the accuracy of such estimations is high. The errors of predictions lie under 0.7 Standard deviation, which will satisfy most of applications.

Comparison of Repetitive Movements Between Ballet Dancers and Martial Artists: Risk Assessment of Muscle Overuse Injuries and Prevention Strategies

Studies show that 64%–80% of professional dancers need to stop performing for extended periods due to Overuse Syndrome (OS). Although ballet and Tae-Kwon-Do seem to have similarities in muscle lengthening, the Tae-Kwon-Do injury rate is significantly lower. Identifying differences between both skills should provide insights for OS prevention. Therefore, the aims of this study are to quantitatively determine the diversities in intensity between both skills, to identify muscles at risk, and to draw possible prevention strategies from the comparison. The methods used were 3D motion capture and biomechanical modeling. Six ballet dancers and five Tae-Kwon-Do artists participated in the study. The results show that intensity during Tae-Kwon-Do is higher than that during ballet, particularly for small muscles. As intensity cannot be responsible for higher injuries, strength training for small muscles and shorter exercise duration in Tae-Kwon-Do may account for the reversed rate; consequently, this is a promising procedure for ballet training. Clearly, further studies are needed to validate this conclusion. This work was supported by Alberta Learning Research Excellence Envelope (Canada) and Teaching & Research Grant of Ministry of Education and Research (Germany). The author would like to thank all of the subjects of the study who donated their time and expertise as well as Brandie Wilde, Kristina Zemp, and Luke Wooldrige for their assistance in conducting the measurements and processing the data.

Informing Music Teaching and Learning Using Movement Analysis Technology.

This study explores the utility of movement analysis technology as a means of contributing to a performance pedagogy informed in part by science. Two research questions were investigated: Can biomechanical skills needed for performance on the violin be accurately and objectively characterized and generalized? Can these data be used to inform performance pedagogy to maximize efficiencies and minimize injury? Movement analysis technology was used to study biomechanical phenomena associated with legato bowing on the violin. Results identified and described generalizable characteristics or markers among expert violinists, interactions between right shoulder and elbow, and three discrete tempo-dependent phases of motor control. Such markers may provide new ways of accurately identifying, assessing, and communicating when teaching. Results hold implications for factors related to overuse injuries and underscore the need for more systematic collaborative inquiry into performance pedagogy. Musikalisches Lehren und Lernen mit Hilfe von Bewegungsanalyse Diese Studie untersucht den Nutzen des Einsatzes von Technologien zur Bewegungsanalyse als Beitrag zur künstlerischen Ausbildung auf wissenschaftlicher Grundlage. Zwei Forschungsfragen wurden untersucht: Können biomechanische Fertigkeiten beim Violinspiel genau und objektiv beschrieben und verallgemeinert werden? Kann man solche Daten dazu benutzen, um die Effizienz der künstlerischen Ausbildung zu erhöhen und Schäden zu vermeiden? Die Bewegungsanalyse wurde eingesetzt, um biomechanische Abläufe im Zusammenhang mit der Legato-Bogentechnik auf der Geige zu untersuchen. Die Ergebnisse erbrachten verallgemeinerbare Merkmale bei Violin-Experten wie die Interaktion von rechter Schulter und Ellbogen und drei tempoabhängige Phasen der Bewegungskontrolle. Solche Merkmale können neue Wege weisen bei den Feststellung, Bewertung und Vermittlung im Unterricht. Ebenso gibt es Hinweise auf Faktoren im Zusammenhang mit Schädigungen durch Überbeanspruchungen beim Üben. Dies unterstreicht die Notwendigkeit einer systematischen Untersuchung im Rahmen der künstlerischen Ausbildung. Un informe sobre la enseñanza y el aprendizaje de la música utilizando la tecnología del análisis del movimiento Este estudio explora la utilidad de la tecnología del análisis del movimiento a modo de contribución a una pedagogía de la ejecución, en parte guiada por la ciencia. Se investigaron dos interrogantes: ¿Es posible caracterizar y generalizar con precisión y objetivamente a las destrezas biomecánicas necesarias para la ejecución del violín? ¿Es posible utilizar esa data para informar a la pedagogía relacionada con la ejecución, con el propósito de maximizar eficiencias y minimizar lesiones? Para estudiar el fenómeno biomecánico asociado al uso del arco legato en el violín se utilizó la tecnología de análisis del movimiento. Los resultados identificaron y describieron características generales o señales entre violinistas expertos, interacciones entre hombro derecho y codo, y tres fases discretas dependientes del tempo de control motriz. Tales señales podrían aportar nuevas maneras de identificar, evaluar y comunicar con precisión al momento de enseñar. Los resultados contienen implicaciones para aquellos factores relacionados con lesiones por uso excesivo, y recalcan la necesidad de una indagación más sistemática y colaborativa dentro de la pedagogía de ejecución.

Impact of Exercise on Seniors' Motor Control Response to External Dynamics∗

Research on postural stability, motor control, and fall occurrence in seniors is common, but few studies address the influence of exercise and external dynamics on elderly balance. Using pre- and post-training tests, the effects of a Fitball® exercise program on performance in eight subjects was documented. The exercise program focused on improving dynamic balance and postural stability of seniors. To evaluate progress-related changes, pre- and post-tests in a dynamic environment were applied. Center of gravity (COG) excursion, catch success rate, and balance success rate were quantified, and synchronized data collection of 3D motion capture (VICON v8i) and ground reaction force (2 KISTLER platforms) was analyzed. During pre- and post-tests, participants stood in a walklike stance and were asked to catch a weighted ball, which dropped unexpectedly. Results showed no significant changes in balance success rate. Significant improvements were found, however, in both COG control and catch success rate following training (p<0.05).

Quantification of Golfer-club Interaction and Club-type’s Affect on Dynamic Balance during a Golf Swing

The current study aimed to provide a holistic picture of efficient golf swing and to determine the club contribution to weight shift patterns. Synchronized data from 3D motion capture (12 cameras, 250 Hz, VICON v8i) and ground reaction force (KISTLER platforms) were collected from 13 advanced golfers. The results showed that a) the club’s dynamic influence was closely related to wrist and elbow control, which determined the degree of separation between centre-of-ground-reaction-force and centre-of-gravity of a golfer; b) a Driver has more influence on a golfer’s weight transfer than an Iron; c) Club head speed is related to the coordination between shoulder and hip joint; and d) the ball release velocity is influenced by wrists “uncock” (a combination of hand extension and ulnar abduction for accelerating the club to its maximum velocity) at ball contact. Via the novel protocol that customizes to subjects’ individual anthropometrical data and separates the body-club system, the current study presents both individual contributing components and more insight view on subjects’ golf swing using different clubs.

A NOVEL MEASUREMENT SYSTEM FOR QUANTITATIVE ASSESSMENT OF AGE-RELATED SENSORI-MOTOR DEGRADATION

Early identification of individuals with impaired balancing ability could lead to timely interventions and reduce the hazard of age-related falls. Numerous methods for researching the prevention of falls and age-related sensori-motor degradation have been proposed and tested. Most are either too expensive for practitioners or too physically demanding to use with seniors. A simple, reliable technique is desired. The aim of this research is to develop a practical and quantitative solution for assessment of age-related degradation of human sensori-motor function, which could in turn serve as a means of fall prevention among seniors. A novel testing apparatus, the dynamic balance testing platform, was developed. The design includes artificial neural network (ANN) technology to address the nonlinearity and redundancy in the neural network that controls sensori-motor functions. A total of 62 male subjects aged from 18 to 84 years were tested using the proposed method. Results showed that (1) the new device did reflect the sensori-motor degradation related to age, (2) reliable evaluation of sensori-motor function need not be complicated, time consuming, or costly, and (3) the developed equipment powered with ANN technology holds great potentials for predicting fall possibility. Overall, this study validated a strategy of fall prevention with a potential for prevalent use in the healthcare industry.

Unraveling mysteries of personal performance style; biomechanics of left-hand position changes (shifting) in violin performance

Instrumental music performance ranks among the most complex of learned human behaviors, requiring development of highly nuanced powers of sensory and neural discrimination, intricate motor skills, and adaptive abilities in a temporal activity. Teaching, learning and performing on the violin generally occur within musico-cultural parameters most often transmitted through aural traditions that include both verbal instruction and performance modeling. In most parts of the world, violin is taught in a manner virtually indistinguishable from that used 200 years ago. The current study uses methods from movement science to examine the “how” and “what” of left-hand position changes (shifting), a movement skill essential during violin performance. In doing so, it begins a discussion of artistic individualization in terms of anthropometry, the performer-instrument interface, and the strategic use of motor behaviors. Results based on 540 shifting samples, a case series of 6 professional-level violinists, showed that some elements of the skill were individualized in surprising ways while others were explainable by anthropometry, ergonomics and entrainment. Remarkably, results demonstrated each violinist to have developed an individualized pacing for shifts, a feature that should influence timing effects and prove foundational to aesthetic outcomes during performance. Such results underpin the potential for scientific methodologies to unravel mysteries of performance that are associated with a performer’s personal artistic style.

A Novel Use of 3D Motion Capture: Creating Conceptual Links between Technology and Representation of Human Gesture in the Visual Arts

ABSTRACT As an unfolding of time-based events, gesture is intrinsically integrated with the aesthetic experience and function of the human form. In historical and contemporary visual culture, various approaches have been used to communicate the substance of human movement, including use of science and technology. This paper links the understanding of human gesture with technologies influencing its representation. Three-dimensional motion capture permits the accurate recording of movement in 3D computer space and provides a new means of analyzing movement qualities and characteristics. Movement signatures can be related to the human form by virtue of trajectory qualities and experientially and/or culturally dependent interactions.

The Selection of Pretest States and Parameters in Identifying the Age Effect Through the Center of Pressure (COP) Measurement

The COP test is a simple tool for judging balance ability. However, its reliability for fall prediction is strongly challenged by its static nature and the contradictory results published in previous studies. The inconsistencies were possible results of negligence of prestate conditions prior to measurement. In this study, we explored these prestate effects on COP by investigating 21 seniors and 28 students. The results show that by adding a dynamic pretest activity, the static COP test could detect dynamic characteristics to a certain degree. Among the three prestates—sitting, standing, and walking—inspected in this study, the best prestate for the identification of age effect is walking. The spectrum analysis determined that the body sway consists mainly of frequencies below 2 Hz, and the age difference lies in the domain of 0–0.8 Hz. Therefore, to study the sensorimotor degradation related to aging, the prestate of walking would be most effective. This study was funded by a University of Lethbridge research grant. The authors would like to thank Prof. Dr. Ge Wu, Department of Physical Therapy, the University of Vermont, for her revision and proofreading of the manuscript.