icSPORTS 2013 Abstracts

Area 1 - Computer Systems in Sports
Full Papers Short Papers
Area 2 - Health, Sports Performance and Support Technology
Full Papers Short Papers
Area 3 - Signal Processing and Motor Behavior
Full Papers Short Papers
Area 4 - Sports Medicine and Support Technology
Full Papers Short Papers

Area 1 - Computer Systems in Sports

Full Papers
Paper Nr: 14
Title:

Soccer Ball Detection in Occluded Situations for Single Static Camera Systems
Authors:

Josef Halbinger and Jürgen Metzler
Abstract: The interest on acquiring player and ball data during soccer games is increasing in several domains such as media. Consequently, tracking systems are becoming widely used for live data gathering. Due to costs, stadium infrastructure, media rights etc. there is a trend for stand-alone mobile low-cost soccer tracking systems. The drawback of such systems is that generally only low-resolution images of the players are available which strongly exacerbates the problem of detection and tracking the soccer ball. Besides difficulties that arise from the appearance of the ball by itself, the detection of the ball in situations where it is occluded by the players is very challenging. This paper presents a tracking framework for the reconstruction of the ball trajectory from monocular low-resolution soccer image sequences. The focus of this paper is the detection of the ball in occluded situations. The approach is tested and evaluated on Bundesliga data sets.
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Paper Nr: 25
Title:

Powerlifting at Junior Level - Selection Paradigm
Authors:

Łukasz Płóciennik and Igor Ryguła
Abstract: The variability of the sport result obtained in powerlifting (PL) causes a few profound problems within coaching practice. One of them is the issue that concerns assigning individuals to particular training group of fitness level. Simply, this process is called selection. Since PL does not have any scientific-based selection algorithm we reckon, it is necessary to project it, with the idea to rationale the procedure. Thus the aims of the study were to construct discriminant and classification functions. A group of thirty-two powerlifters was selected for the investigation (22,397 yr ± 0,826). The average sport result was 331,449 ± 41,959 Wilks Points. Observation method and diagnostic survey were used to collect the data. During the course of the multidimensional statistical analysis, Hellwig’s algorithm, multiple regression, and discriminant analysis were utilised. The distances between stratified subdivisions of athletes were maintained in 99%. The classification matrix of young powerlifting contestants indicates that all the athletes were grouped adequately. Finally, for junior age category in PL, classification functions assign individuals to specified subgroups statistically better than a priori rule.
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Paper Nr: 35
Title:

User-friendly Smartphone App for Heart Rate Monitoring in Sports Endurance Activities - Improving Training Control by Combining New Technologies of ANT+ and Android
Authors:

Hans Weghorn
Abstract: In endurance sports training, heart rate represents a useful proportional measure for the current physical effort in a workout. Accordingly, during such exercises, it is advantageous to get monitoring information about the actual heart frequency for having an instrument of controlling the demand level of an activity. Today, the market offers a broad variety of sports computers, which allow a tracking and display of heart rate, but their convenience and appropriateness appear rather limited in terms of an efficient use in daily training. In particular, major restrictions are numerical displays of the in-time measures with tiny letters or an unfiltered print-out of spurious values, since the recording is not always precise, but sometimes disturbed from various reasons. Fortunately, upcoming new technologies like programmable smartphone devices and ANT+ communication standard for sports sensors allow developing new and optimized applications and systems also for sports purposes. In the work here, a convenient heart rate monitor was developed that aims at high user-friendliness in combination with elaborated signal-conditioning for preventing any spurious and misguiding displays. Few simple button presses put the sportsman into the position of performing efficient activities within the desired endurance training range. As result, a system is described that is feasible for easy-to-use and efficient sports monitoring, especially during daily workouts.
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Paper Nr: 44
Title:

MOPED: An Agent-based Model for Peloton Dynamics in Competitive Cycling
Authors:

Erick Martins Ratamero
Abstract: MOPED (an acronym for Model of Peloton Dynamics) is a proposed model for peloton dynamics in competitive cycling. Using an agent-based approach, it aims to generate the very complex behaviour observed in real-life competitive cycling from a collective of agents with very simple rules. Members of a peloton try to minimize the average energy expenditure by riding behind other cyclists, in a behaviour known as drafting. Drafting cyclists spend considerably less energy than frontrunners, making many different strategies possible. We incorporate physiology concepts trying to quantify energy expenditure and recovery in different scenarios. Starting from a very simple model of identical cyclists, multiple iterations with increasing complexity are proposed, incorporating more and more aspects of the real physics involved in this sport. Finally, we analyse the results and try to compare them to real-life behaviour to validate the model.
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Short Papers
Paper Nr: 33
Title:

Proficiency Estimation by Motion Variability obtained from Single Camera Input
Authors:

Ayumi Matsumoto, Dan Mikami, Harumi Kawamura and Akira Kojima
Abstract: This paper proposes a motor learning assist system that estimates the proficiency of a trainee in making sports motions on the basis of variability of his/her own 3D motions in trials captured by a single camera. Most existing systems assume that a sequence of human poses must be obtained by multiple calibrated cameras or a marker-based motion capture system. Such systems can be effectively used by professional athletes or broadcast station personnel who specialize in sports, but not by casual sports fans who have no particular athletic skills. We propose a method for evaluating proficiency based on the variance of the 3D motion when it is subjected to repeated trials. It has two important features. First, it requires only a free-position single camera by employed the 3D pose estimation method independent of camera position. It can be used not only by elite athletes but also by casual sports fans. Second, it estimates proficiency only from a trainee's own motion and thus does not require any reference movements. In this paper, the golf swing is used as the target of motor learning.Experiments result shows that variability of 3D motions in trials is inversely proportional to the degree proficiency.
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Paper Nr: 56
Title:

The Mobile Motion Advisor - An Intelligent Real-time Feedback System
Authors:

Arnold Baca, Philipp Kornfeind and Martin Tampier
Abstract: Athletes and coaches require effective methods to support and guide the training process. As a consequence of advances in technology, systems are constructed, which present relevant sports specific feedback information during and shortly after training and competition. Our intention is to combine mobile data acquisition methods with centralized analysis routines and feedback functionality for supporting athletes. The approach is based on a feedback system providing mobile and almost real time solutions for wireless body sensor data transmission, processing and feedback provision. Together with the use of appropriate technologies (hardware and software) the following goals can be achieved: • Assistance during sport activities • Improvement of training performance • Avoidance of overload • Increase of motivation by individual feedback (e.g. for school-classes)
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Paper Nr: 76
Title:

Application of Mobile Technologies in the Preparations for Long Distance Running
Authors:

Ladislav Havaš, Vladimir Medved and Zoran Skočir
Abstract: Fast development of mobile ICT technologies has enabled and imposed their implementation in many business, private and sport areas. As mobile technologies enable quick and two-way communication, independent of the present location of an athlete, their trainer or expert hardware and software systems, it is of the significant importance to utilize the advantages of that kind of communication in order to maximize the chances of achieving excellent results in a specific training process or in a key race. In this paper is shown one ORT (Online Running Trainer) system, which was developed for preparations of long-distance runners. It describes a new algorithm for calculation of training equivalents of set and achieved trainings, which was used for the success analysis of every micro cycle of the training process. By using all available telecommunication channels, ORT system communicates with its users in real time. Moreover, it analyses their performance and, if necessary, dynamically corrects their training parameters in order for them to achieve better results in needed moment. Described methods and procedures are verified on a selected sample of marathon runners.
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Area 2 - Health, Sports Performance and Support Technology

Full Papers
Paper Nr: 50
Title:

Fully Organic Graphene Oxide-based Sensor with Integrated Pump for Sodium Detection
Authors:

Jingfeng Huang, James Harvey, Hu Chen, Steve Faulkner, James King, Myra A. Nimmo and Alfred Tok I. Y.
Abstract: Sweat is produced by the body naturally during physical activity and this fluid can be analysed in real-time to reflect the body’s hydration and electrolyte status. This paper reports a new type of organic disposable sensor pump that integrates sweat collection and sodium (Na+) ion sensing into cotton threads. This integration allows the sensor platform to be small, portable and wearable; thus allowing potential advantage to interface with the human body during field exercises enabling the provision of real-time data for immediate intervention. The sensor uses a sodium-selective Ion Selective Electrode (ISE) modified graphene oxide transducer intertwined with a thread pump. In this paper, we present the characterisation, synthesis and sensing data of this sensor.
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Short Papers
Paper Nr: 9
Title:

Special Strength and Conditioning Profile of Elite Chinese Female Wrestlers
Authors:

Z. H. He
Abstract: Our hypothesis that measures of special strength and conditioning parameters would differentiate between more successful and less successful elite Chinese female wrestlers. The Olympic and world championship medallists had the highest value for dead lift and hold and squat, but other parameters did not attain significant difference. This indicates strength and power, but not aerobic ability differentiates between very successful female wrestlers and less successful female wrestlers. The percentile physiological profiles can help wrestlers and coaches to individualize the training program to minimize physiological weaknesses and develop wrestling strategies to take advantage of individual wrestler’s strengths.
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Paper Nr: 19
Title:

Relationships between Sagitall Postures of Cervical Spine and Shoulder and Presence of Neck and Shoulder Pain in Adolescents
Authors:

R. M. Ruivo, P. Pezarat-Correia and A. I. Carita
Abstract: Purpose: This study characterized the postural alignment of the head and shoulder in the sagittal plane of Portuguese adolescents, 15-17 years old, in natural erect standing and explored the relationships between three postural angles and presence of neck and shoulder pain. Gender differences were also considered. Moreover, the reliability of the photographic measurement of the sagitall posture of cervical spine and shoulder was investigated. Methods: The study was conducted in 2 secondary schools in Portugal. 275 adolescent students (153 females and 122 males) ages 15-17 were evaluated. Sagittal head (HT), cervical (CV) and shoulder angle (SH), were measured with photogrammetry and PAS software. American shoulder and elbow surgeons shoulder assessment (ASES) were used to asses shoulder pain. Results: Mean values of HT, CV and SH angles were 17.26±6.7, 47.40±5.2 and 51.41±8.5º respectively. 68% of the adolescents studied revealed protraction of the head whereas 58% of them had protraction of the shoulder. The boys showed a significant higher mean CV and HT angle than girls and adolescents with neck pain revealed lower mean sagittal and cervical angle thant adolescents without neck pain. Neck pain is more prevalent in girls with 52,9% of them self-reporting to feel neck pain regularly, contrasting with the 19% for the boys. Conclusions: This data shows that forward head and rounded shoulder are common postural disorders in adolescents, especially girls. Neck pain is prevalent in adolescents, specially girls and is associated with forward head posture.
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Paper Nr: 21
Title:

Exercise Testing in Professional Cyclo-cross Athletes - Bike or Run?
Authors:

Dirk Vissers, Hedwig Neels, Nick Pieters, Glenn Bosserez, Guy De Schutter and Jan Gielen
Abstract: Background: Cyclo-cross is contested on a looping course that includes barriers, steps and piles of sand. Because the athletes can choose to bike the course all the way, or carry their bike and run, training can be focused on biking and/or running. Objective: The purpose of this study was to investigate the difference between the results of an exercise test on a treadmill and a cycle ergometer in cyclo-cross athletes. Methods: Six elite (age 25 ±3) and five U23 (age 19 ±1) professional cyclo-cross athletes performed two maximal exercise tests, one on the cycle ergometer and one the treadmill, in the beginning end at the end of the cyclo-cross season at the S.P.O.R.T.S. department of the Antwerp University Hospital. Ergospirometric and blood lactate parameters were analyzed. Results: Maximal lactate, maximal ventilation and VO2peak were significant higher the cycle ergometer test compared to the treadmill tests. Overall, heart rates at anaerobic threshold were not significantly different between the ergospirometric method (Wasserman) and the blood lactate method (Keuhl). Conclusion: Results of a maximal exercise test on a treadmill are significantly lower compared to the results on a cycle ergometer in cyclo-cross athletes. The limited running capacity of cyclo-cross athletes should be taken into account when choosing a protocol for exercise tests on a treadmill.
Paper Nr: 52
Title:

Electronic Monitor for Monitoring TV Viewing Time - Description and Significance
Authors:

Mohammad Ali Alahmadi
Abstract: Sedentary behaviour is related to adverse cardiometabolic risk profiles and premature mortality. Television (TV) viewing time is the most predominant sedentary behaviour. There are also adverse associations between TV viewing time and a number of cardiovascular risk factors such as the metabolic syndrome, obesity, and abnormal glucose metabolism. Few measurement tools, such as direct observation and videotaping, have been utilized to objectively monitor TV watching. Unfortunately, these measurements have shortcomings as they invade the personal privacy and are impractical in large-scale research studies. Therefore, there is a need for alternative objective measures. Therefore, the main aim of this paper is to design an electronic device to objectively monitor TV viewing. This device uses Radio-frequency identification (RFID) technology that transfers data using tracking tag that is attached to a child's wrist like a watch. This data will be collected by the RFID Reader which is connected to a main electronic board that is designed to measure TV viewing time in minutes. The current research is expected to produce a novel wireless electronic tool that can monitor TV viewing without intrusion to the person privacy and can be widely used as an objective method of assessing TV viewing time.
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Paper Nr: 55
Title:

Quantitative Assessment of a Functional Movement Screen in Athletes using a Wireless Body Area Sensor Network
Authors:

Suryadip Chakraborty, Saibal K. Ghosh, Anagha Jamthe, Dharma P. Agrawal, Robert Mangine, Angelo Colosimo and Joe Rauch
Abstract: Technological solutions enabling the monitoring of human motion during sports and exercise by collecting quantifiable measurements are gaining increased attention as tools for evaluating progress in rehabilitation. Wireless technologies employing small sensors are particularly useful since they allow monitoring of kinematic data without affecting individuals in executing their motions. Advances in miniaturized and wireless technology will push capturing and clearly illustrate measurements in real time game situations. This will eventually eliminate capturing forces from simulated situations in the training room and tell us what actually happens on the playing field.
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Paper Nr: 64
Title:

A Pilot Investigation into a Measure of Table Tennis Movement Efficiency using Kinetic Data
Authors:

Dino A. Palazzi, Jonathan A. Glynn and Benjamin K. Williams
Abstract: The objective of this pilot investigation was to attempt to develop a movement efficiency score from a mathematical equation using force plate data captured during an alternating forehand-backhand rally involving lateral movements at the base of the table. The resultant movement efficiency score could be useful for objectively tracking skill development/efficiency in players and monitoring the effectiveness of coach/scientist intervention.
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Paper Nr: 65
Title:

Transcranial Direct Current Stimulation Improves the Cycling Performance but Does Not Alter Neuromuscular Function - tDCS, Cycling Performance and Neuromuscular Function
Authors:

Leandro Ricardo Altimari, Marcelo Vitor-Costa, Henrique Bortolotti and Nilo Massaru Okuno
Abstract: OBJECTIVES: The main neurophysiologic mechanisms that determine performance in physical activities or sports are not well understood. This is mainly due to the lack of technology that permits the study of the human brain in vivo. In the last decades some neuromodulation techniques have been developed and, among them, the transcranial direct current stimulation (tDCS) has been attracting attention as it is easily applicable and permits to carry out well controlled studies in humans, and has been shown to be a strategy to enhance physical and mental performance in sports (Davis, 2013). Therefore, the objective of the present study was to investigate the effects of anodic tDCS on the physical performance and neuromuscular function in cycling exercise. METHODS: A total of 11 physically active subjects aged 26 ± 4 years, weighing 77 ± 15 kg and 177 ± 3 cm tall participated in study. Initially all subjects performed an incremental test in a cyclesimulator (model Velotron DYNAFIT PRO™, RacerMate Inc., USA) to determine the peak power (257 ± 35 W). In the two subsequent visits to the laboratory the subjects were randomly submitted to one of the two stimulation conditions (Anodic tDCS or Placebo tDCS) to verify their possible effect on a time to exhaustion task at 80% of peak power (205 ± 28 W). This study was approved by the local Institutional Research Ethics Committee. Stimulation was carried before each test during 13 min, with a current intensity of 2.0 mA. The time between tDCS and the test was 10 min. Sessions were separated by a minimal interval of 48h. We used the 10-20 International System for EEG electrode placement. The active electrode (9x4 cm) was placed on the scalp having its center in the region Cz 4.5 cm on each side of the head (purpose of stimulating the motor cortex of both hemispheres), and the reference electrode was positioned over the bulge. Additionally, the electromyographic (EMG) signal of the muscle vastus lateralis (VL) was monitored during tests after stimulation and expressed in mean values of RMS - root mean square (µV) and MF - median frequency (Hz) with a 5-second window period. For EMG signal normalization a test for torque-speed [T–V test] was used (Rouffet and Hautier, 2008). For the recording the of EMG signal, was used an electromyography model TeleMyo 2400TG2™ (NORAXON Inc., USA) and bipolar active EMG electrodes (modelo TeleMyo 2400™, NORAXON Inc., USA), with interelectrode distance fixed at 2 cm, which were placed in the right leg muscle and fixed with a adhesive tape. Initially, a trichotomy followed by asepsis with alcohol and curettage of the electrode site, to reduce skin impedance, was performed. The localization of anatomical point for the electrode placement on the analyzed muscle was done according to the standardization proposed by the Surface ElectroMyoGraphy for the Non-Invasive Assessment of Muscles ISEK: International Society of Electrophysiology and Kinesiology (SENIAM). The sampling frequency of the EMG signals was 2.000 Hz. The signal passing limit was ±5 mV, and the common-mode rejection ratio was 95 dB. To obtain the values expressed in RMS, the raw EMG signals were submitted to a band-pass digital filter of 20 and 500 Hz and then rectified and smoothed. The MF was determined using Fourier analysis —‘‘Short-Time Fast Fourier Transform’’ — and the signals were processed in the mathematical simulation environment MatLab 7.0™ (Mathworks Inc., USA). For statistical analysis of the data was used paired Student t-test and ANOVA two-way. Significance level was set at 5%. RESULTS: The results demonstrated that there was an increase (p<0.05) in exercise time when individuals received Anodic tDCS (491 ± 100s) in comparison to Placebo tDCS (407 ± 69s). These results were confirmed by the size effect (anodic x placebo = 0.77). When the magnitude-based inference was applied, the anodic stimulation condition was most probably positive to individuals when compared to placebo conditions. However, no significant differences were found for the parameters of neuromuscular function - EMG signals RMS (Figure 1A) and MF (Figure 1B) - among the two experimental conditions. DISCUSSION: The increase in exercise time with application of anodic current has been shown previously in isometric exercise of the upper limb. Cogiamanian et al. (2007) showed that anodal stimulation (1,5 mA), applied for 10 min after a fatigue test increased tolerance to an exercise performed subsequent to stimulation without changes in EMG. These findings are in agreement with those found in this study. Furthermore, some authors have shown that tDCS can improve performance on other tasks increasing muscle strength. Tanaka et al. (2009) have shown that, in healthy subjects exerting pinch strength in the toes, the anode tDCS causes increases in strength both during and after 30 min of stimulation. More recently, in another study with patients who have suffered stroke, Tanaka et al. (2011) found an improvement in knee extension strength of the paretic leg during application of anodal tDCS, but after 30 minutes there was no difference (Tanaka et al., 2011). Thus, it may be concluded that anodic TDCS increases exercise time. However, the mechanisms responsible for the greater exercise tolerance are speculative. It is possible that the increase in intracortical facilitation causes the individual to support longer in exercise. REFERENCES Cogiamanian, F., Marceglia, S., Ardolino, G., Barbieri, S., Priori, A. 2007. Improved isometric force endurance after transcranial direct current stimulation over the human motor cortical areas. European Journal of Neuroscience. 26(1):242-249. Davis, N.J. 2013. Neurodoping: Brain stimulation as a performance-enhancing measure. Sports Med. [Epub ahead of print] DOI: 10.1007/s40279-013-0027-z. Rouffet., D.M., Hautier, C.A. 2008. EMG normalization to study muscle activation in cycling. Journal of Electromyography and Kinesiology. 18(5):866-878. Tanaka, M., Takeda, K., Otaka, Y., Kita, K., Osu, R., Honda, M., Sadato, N., Hanakawa, T., Watanabe, K. 2011. Single session of transcranial direct current stimulation transiently increases knee extensor force in patients with hemiparetic stroke. Neurorehabilitation and Neural Repair. 25(6):565-569. Tanaka, S., Hanakawa, T., Honda, M., Watanabe, K. 2009. Enhancement of pinch force in the lower leg by anodal transcranial direct current stimulation. Journal of Physiology Experimental Brain Research. 196(3):459-465.
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Paper Nr: 68
Title:

Nintendo Wii as a Training Tool on Quality of Life in Elderly
Authors:

Josimara Cristina Alves, Gustavo Augusto Alves Rodrigues, Eric Fernandes Dias, Elisangela Silva, Wagner Zeferino Freitas, Fabiano Fernandes da Silva and Renato Aparecido de Souza
Abstract: In recent years has grown the number of researches related to technology in the health of the elderly, among them Virtual Reality, which have favorable results particularly using the Nintendo Wii. The aim of this study was to assess the quality of life of ten non-institutionalized elderly (58 ± 6.4 years old) submitted to a training protocol in virtual reality generated by Nintendo Wii. The exercise training protocol consisted of eight sessions with 60 minutes of duration, and twice a week. Games of Wii Fit Plus software and the Balance Board of Nintendo Wii were used for training protocol. The guidelines of health agencies, as American College of Sports Medicine (ACSM), were used to design the training program. The assessment of quality of life was measured with the SF-36 questionnaire. The results indicated that the Nintendo Wii is beneficial to improve the quality of life of elderly healthy and functionally independent.
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Paper Nr: 69
Title:

Physiological Responses While Playing Games Virtually Simulated by Nintendo Wii
Authors:

Gusthavo Augusto Alves Rodrigues, Danilo Souza Felipe, Elisangela Silva, Wagner Zeferino de Freitas, Fabiano Fernandes da Silva and Renato Aparecido de Souza
Abstract: Nintendo Wii is a domestic console able to create a virtual environment. Nowadays, it has been investigated as a tool to promote physiological stress. The aim of this study was to compare the percentage of VO2 max and maximal heart frequency (HR max) in different games (balance and aerobic) of Nintendo Wii Fit Plus in young adults. This is an interventional and comparative study. Participated in the study, nine healthy male college students (20.6 ± 2.01 years, 173.6 ± 3.8 cm, 73.6 ± 8.81 kg, lean body mass 84.0 ± 5.96 %, fat body 16.00 ± 5.96 %, and VO2max 55.8 ± 5.46 ml/kgˉ¹/minˉ¹). The VO2 and the Heart rate were assessed during the practice of aerobic and balance games of Wii Fit Plus software. The results of this study support the feasibility use of the Nintendo Wii in training programs and favor its indication more securely. Considering the low cost of this technology coupled with elements of interactivity to its nature, it is recommended the use of this tool for the promotion of health.
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Paper Nr: 72
Title:

Challenges and Opportunities in Developing a Test Battery for Joint Mobility using Reach Tasks Starting from Upright Standing Positions
Authors:

O. Eriksrud, P. Anderson, E. H. Andreassen, S. Litsos, F. O. Sæland, P. Federolf and J. Cabri
Abstract: This study investigated if a systematic combination of upright standing reach tests may be used as a test battery for the assessment of joint mobility and identified potential challenges. In addition, it was assessed if selected conventional tests of mobility are correlated with performance in the reach tests. Eight male volunteers executed a series of 20 reach tasks. Their movements were recorded with a 14-camera motion tracking system using a whole-body marker set. Joint ranges of motion were also determined in 4 conventional mobility tests. In all reach tests significant correlations were found between the reach distance and a specific set of joint angles as well as with anthropometric measures. Joint range of motion, as determined in the conventional tests, correlated with reach performance only in 7 of 22 analyzed comparisons. These results suggest that reach tests may offer an approach to test joint mobility in situations closer to “real-life”, however, scaling of anthropometric properties, stability, and balance issues have to be considered.
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Paper Nr: 74
Title:

A Knowledge Sharing Environment for Sport Management
Authors:

André Boder and Christophe Barthe
Abstract: The European football governing body (UEFA) has developed a unique environment to share good practices. It includes blended learning (including face-to-face and on-line interactive courses), knowledge sharing platforms and 3D virtual stadium to access specific topics in sport event management. The various functionalities include solutions to typical knowledge management issues, such as contextual versus generic knowledge or yet strategies to turn tacit knowledge into explicit knowledge. The environment provides access to libraries of good practices in the form of learning objects as well as hints to solve critical problems in each of the domains of sport management. In addition, the environment is built in a modular way (knowledge elements consist in storytelling and lessons learned in the form of short video items) which allows for reorganisation of modules in various forms to generate new scenarios for further learning. In doing so, the environment is a typical implementation of the recursive nature of the knowledge circle including creation, collection, organisation and reuse.
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Area 3 - Signal Processing and Motor Behavior

Full Papers
Paper Nr: 38
Title:

The Use of Timing Control Strategies to Overcome Severe Time Constraints during Rapid Interception
Authors:

Tetsuya Ijiri, Masahiro Shinya, Kohtaroh Hagio and Kimitaka Nakazawa
Abstract: We investigated the mechanisms underlying timing of rapid interceptive actions under severe time constraints, such as those required in baseball, cricket, and tennis. To compensate for the temporal uncertainty of a moving target, participants were required to control their movement onset and/or duration. In Experiment 1, we tested how movement onset and/or duration are controlled under severe time constraints in a rapid baseball-simulation interceptive task. We found two distinct control strategies that modulated task performance. We also found that corrections to ongoing movements occurred more rapidly than had previously been reported. In Experiment 2, we used startling acoustic stimulation to investigate the detailed mechanisms underlying decisions about the timing of movement onset. Our findings indicate that the timing of movement onset is modified continuously via a subcortical motor circuit. Overall, our findings indicate that rapid movement decisions rely on a hybrid of feedforward and feedback control, allowing for the circumvention of severe time constraints during rapid interceptive actions.
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Paper Nr: 58
Title:

Suboptimal Strategy in Performing Coincident Timing Task under Risk
Authors:

Keiji Ota, Masahiro Shinya and Kazutoshi Kudo
Abstract: The best performance often goes hand in hand with risk in many sports. Players are engaged in considering how much risk they take. Some studies reported that movement strategy is modified by risk-sensitivity. Here, we investigated how people responded under risk to which high gain got closer to zero　gain. We designed new coincident timing task in which participants were rewarded with the highest score if they pressed a button just at a target time (2300 ms) but they did not get a score if they responded after the target time. In this task, the participants should take the variability of their response into account and take a risk-neutral strategy to get the highest total score that was theoretically calculated. However, we found out that the participants took a risky response compared with an estimated optimal response. This risk-seeking strategy degraded a task performance. These results suggest that not only small variability in response but also taking an optimal strategy is important to get higher performance under risk.
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Paper Nr: 71
Title:

Turn Detection and Characterization with Inertial Sensors
Authors:

Sean Pearson, Martina Mancini, Mahmoud El-Gohary, James McNames and Fay Horak
Abstract: Turn detection and characterization in the home is important for continuous assessment of gait and balance in people with movement disability. Turning often results in falling in individuals with movement disorders. Researchers and clinicians would benefit from a system that identifies and characterizes their daily mobility behavior to predict their risk of falling, benefits or side effects of treatment, and progression of disease. The goal of this study is to develop an algorithm that is capable of reliably detecting turns during gait with the goal of applying it over long periods outside a lab environment. Performance of the algorithm is validated against an optical marker system and video analysis of a subset of the participants.
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Short Papers
Paper Nr: 11
Title:

A New Simple Method for Kinematic Detection of Gait Events
Authors:

Xiaolei Lv, Yi Wei and Shihong Xia
Abstract: The detection of gait events in locomotion, such as toe-off and heel-strike, provides a basic criterion for the division of a step cycle. This paper presents a new simple method for kinematic detection of gait events using kinematic data captured from only one marker attached to heel. We analyze the geometric distribution of the markers spatial positions over a small window of frames, and find there are new characteristics on the curve. These characteristics are used to detect the gait events for normal gaits. True errors (mean±standard deviation) in the experiments on normal gaits are 8±8 ms for heel-strike and 12±20 ms for toe-off, where above 91% of subjects’ heel strike events can be determined, with at most one frame (8.3 ms) error away from the ground reaction force (GRF) results.
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Paper Nr: 20
Title:

Static Foot Pressure Characteristics among Sprint Athletes
Authors:

Tong-Hsien Chow, Hui-Jong Huang and Wei-Gang Chang
Abstract: The arch is an anatomical structure of foot in humans that influences the motor functions of the lower limb and also causes changes in the plantar pressure distribution of the foot. Plantar pressure measurement is an effective method of assessing plantar loading, and can be applied to evaluate the motor behavior expression of the foot. The purpose of this study was to investigate the static foot pressure characteristics during the long-term training of sprint athletes. The subjects were divided into two groups, namely the 80 top-level sprinters (the sprint group) and 247 healthy non-athletics control subjects of the same age. An optical plantar pressure device (JC Mat) was employed to evaluate the differences in the arch index (AI), differences in the plantar pressure distribution (PPD) of three districts from the front of the foot to heel, differences in the PPD of six individual sub-districts, variation in foot shape among the subjects and the presence of any related physiological symptoms of subjects. A normal range of AI (0.21-0.22) was observed among the male control group, while a high-arch range (0.19±0.09) was found among the female control group. The AI values for both feet of the male athletes were significantly less than those obtained from the control group (p < .01). The PPD readings showed a low value on the lateral longitudinal arch of middle foot region, and a main focus on the calcaneus of both feet, and the medial metatarsal of the front foot region of left foot in the sprint group as compared with controls. The results of the analysis of foot-shaped images were consistent with the AI and PPD readings and show the same pattern. The present findings indicate that the sprint group showed a high-arch foot shape in the AI, and an increased PPD of the forefoot (medial metatarsal) of left foot, and the rearfoot of both feet. The self-descriptive physiological situation of athletes is considered to be consistent with the high-arch related foot symptoms. The change in AI may be affected by age, sex, BMI values, measurement, and the number of samples.
Paper Nr: 22
Title:

Somatotypical Profile Characteristics of Professional Cyclocross Athletes
Authors:

Dirk Vissers, Hedwig Neels, Glenn Bosserez, Nick Pieters, Guy De Schutter and Jan Gielen
Abstract: Background: Cyclocross is contested on a looping course that includes barriers, steps and piles of sand. Athletes can choose to bike the course all the way, or carry their bike and run. This mix of biking and running implies specific physiological and physical characteristics are needed to perform at top level. Objective: The purpose of this study was to investigate the characteristics of the somatotypical and anthropometric profiles of professional cyclocross athletes. Method: Triceps, subscapular, supraspinale measurements and the thickness of calf and skin, humerus bicondylar, femur bicondylar, bicepsgirth, weight, and height measurements were taken of six elite and five U23 professional cyclocross athletes (age 23±4) at the S.P.O.R.T.S. department of the Antwerp University Hospital. Somatotypical calculations and analyses were completed using Somatotype 1.2.5 and IBM SPSS 18.0 software. Results: Results were situated on the mesomorphy – ectomorphy line. There was no significant difference between the results of elite riders and U23 riders. The overall mean result was 3.40±0.56 for mesomorphy, 3.50±0.76 for ectomorphy and 1.50±0.35 for endomorphy. There was no significant difference between, fat percentage, fat mass and fat free mass of elite riders and U23 riders. Overall body weight was 66.6±4.6 kg, body mass index was 20.8±1.3 kg/m2 and fat percentage was 5.19±1.53%. Conclusions: No differences between somatotypical profiles in elite riders and U23 riders were found. Professional cyclocross athletes have a somatotypical profile that is situated on the mesomorphy – ectomorphy line and a low fat mass.
Paper Nr: 23
Title:

Space Perception by Acoustic Cues Influences Auditory-induced Body Balance Control
Authors:

Shinichi Yamagiwa, Naka Gotoda and Yuji Yamamoto
Abstract: The auditory-induced illusion called vection has been investigated for decades. However, it is not confirmed how the illusion affects to body balance. Especially, during a dynamic activity such as walking, it has not confirmed whether any clear effect to the body balance control appears or not. This paper focuses on investigating the effect of vection during walking. Especially this paper will discuss the space perception induced by acoustic stimuli that indicate the directions. The authors of this paper measured the response time from the acoustic cue to body balance control and the rotation amount using a small sensor system with accelerometer, magnetic and gyro sensors. According to the experiments with sight/blind participants from young to old ages, requesting them to walk to the directions of the acoustic cues with/without sight, the authors confirmed a close relation between the vision and the auditory of human during a dynamic activity.
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Paper Nr: 61
Title:

Conscious Drive to Stiffen the Leg Spring - Motor Strategies for an Internal Challenge
Authors:

Mervyn Travers, James Debenham, William Gibson, Amity Campbell and Garry Allison
Abstract: This study investigated the kinematic and muscle activity profiles at the ankle under two hopping conditions that consciously altered leg stiffness. Nine healthy volunteers performed multiple trials of bilateral hopping on a custom built sleigh under two conditions – preferred (PC) and short contact (SC). Leg stiffness, peak EMG, time to peak EMG and co-activation ratios for the medial gastrocnemius (MG), soleus (Sol) and tibialis anterior (TibAnt) muscles were compared across conditions. SC hopping resulted in increased leg stiffness. Importantly, Sol onset shifted from 86ms post-contact during PC to 14ms post-contact for SC. Similarly, MG onset was 41ms post-contact during PC and 22ms pre-contact for SC. Significantly earlier onsets of Sol and MG represent a shift into the feed-forward window which was not reflected by TibAnt. Comparisons revealed no significant differences in co-activation ratios (p>0.05) suggesting that increased leg stiffness during SC hopping was not a result of increased co-activation. Instead a dynamic strategy pairing pre-activation with an increased rate of activity of the agonist muscles to develop force in time for contact with the surface was observed. We suggest that the optimal strategy to consciously drive increased leg stiffness occurs via a feedforward response.
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Paper Nr: 62
Title:

If Proprioception Is Relevant to Locomotion, then Why Test It Standing Still?
Authors:

Mervyn Travers, James Debenham, William Gibson, Amity Campbell and Garry Allison
Abstract: Traditionally, proprioception research has utilised passive position or movement detection and repositioning tasks. Current evidence suggests proprioception represents a complex synergy of sensory inputs that may be more appropriately assessed during more functional tasks. This study investigated the Minimal Perceptible Difference (MPD) test - a novel assessment of participants’ ability to perceive floor height changes whilst hopping. Sixteen healthy volunteers performed multiple hopping trials on a custom-built sleigh apparatus that permitted a floor height change (range 3mm to 48mm). The MPD in floor height was recorded for 8 different hopping conditions (Factors - Technique: alternate / bilateral hopping; Side: dominant / non dominant; Direction of change: up / down) over two separate testing occasions. Within and between-day reliability were assessed using ICC and 95% confidence intervals. Hopping technique was the only factor which significantly influenced participants’sensitivity to detect changes in floor height. The mean MPD was significantly lower (p<.0001) for bilateral hopping (15.65mm) when compared to alternate hopping (26.59mm). Bilateral hopping yielded strong ICC for within and between day reliability. We propose the bilateral hopping MPD assessment is a reliable, functional assessment of proprioception sensitivity that may better reflect human gait than established static assessments.
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Paper Nr: 67
Title:

Effect of Contralateral Condition during Bimanual Pinch Force Control
Authors:

Kazumi Critchley, Toshiyuki Kurihara and Tadao Isaka
Abstract: The purpose of this study is to investigate the effect of the interaction of different control of the opposite side during bimanual finger pinch force output. Thirty two young adults (20.5±2.0y) participated in this study. Participants were requested to control their pinch forces at 10%MVF with visual feedback. Participants were asked to turn off their force output to zero (0%MVF) if visual feedback disappeared, and maintain their force output at 10%MVF when it’s appeared. There are 4 different force producing types: increase force output from 0 to 10%MVF (UP), decrease force output from 10 to 0%MVF (DOWN), keep maintaining 10%MVF (KEEP) and waiting at 0%MVF force output level (WAIT). The error trial was defined as when UP side of the hands’ force output exceeded 10.6%MVF. We calculated the error ratio as the number of error trials per total numbers of trial. The number of error ratio was the fewest on UP&UP, total 25/198 (Left: 17/96 Right: 8/96), followed by KEEP&UP total 52/192 (Left: 28/96, Right: 24/96) and WAIT&UP total 64/191 (Left: 40/96, Right: 24/95). Most mistakable condition was DOWN&UP, total 81/192 (Left: 50/96, Right: 31/96). The overshoot error ratio in right hand was lower than that of left hand.
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Paper Nr: 73
Title:

Effects of Age and Stimulus Velocity in the Performance of a Complex Coincidence-anticipation Task by Children and Adults
Authors:

Teresa Figueiredo and João Barreiros
Abstract: This study investigated the effect of stimulus velocity in a complex coincidence anticipation task performed by children and adults. Participants were required to throw a ball to hit the luminous stimulus of a Bassin Anticipation Timer in coincidence with its motion, and they performed five 24-trial blocks with the target speeds of 0.36 m/s, 0.71 m/s, 1.61 m/s and 3.21 m/s. Results showed more accurate and consistent performance for adults at all target speeds, as well as a deterioration in the measures of AE and VE with increasing stimulus speed. Furthermore, a dominant linear trend was found to explain performance changes in adults and children at the various target speeds. The discussion focuses on the constraints of complex coincidence anticipation tasks related to perceptual and motor demands.
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Area 4 - Sports Medicine and Support Technology

Full Papers
Paper Nr: 41
Title:

Achilles Tendinopathy is a Troublesome Sports-related Condition Involving Blood Vessel Ingrowth into the Tendon Tissue - Studies on the Adjacent Plantaris Tendon and the Peritendinous Connective Tissue Suggest that TNF-alpha can be Highly Involved in the Vascular and Tissue Changes
Authors:

C. Spang, H. Alfredson and S. Forsgren
Abstract: Achilles tendinopathy/tendinosis is a troublesome condition which is frequently occurring in response to sports related activities. It can lead to an ending of the sport activity. There is evidence which shows that ingrowth of blood vessels occurs from the peritendinous tissue. In well-established treatments the areas of these vessels are targeted. In Achilles tendinosis there is frequently a coalescing of the plantaris tendon with the Achilles tendon. TNF-alpha is known to be involved in blood vessel remodelling events and angiogenesis. With these facts as background, the peritendinous connective tissue located inbetween the plantaris and Achilles tendons and the plantaris tendon itself in cases with Achilles tendinosis were evaluated concerning expression of TNF-alpha and TNF receptor II (TNFRII). It was found that there were expressions of TNF-alpha in the numerous cells located in the peritendinous connective tissue and that the very frequently occurring blood vessels located in this tissue as well as in the tendon tissue exhibited marked TNFRII reactions. The tenocytes were shown to exhibit moderate TNF-alpha reactions and very strong TNFRII reactions. The observations suggest that TNF-alpha is highly involved in the blood vessel remodelling in tendinosis and that TNF-alpha also is involved in tenocyte function.
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Short Papers
Paper Nr: 39
Title:

Implications of the Intervention Program for Physical Activity (IPPA) in the Perception of Illness and Wellbeing in People with Multiple Sclerosis (MS)
Authors:

Luísa Pedro, José Pais-Ribeiro and João Páscoa Pinheiro
Abstract: The aim of this study is to examine the implications of the IPPA in the perception of illness and wellbeing in MS patients. Methods - This is a quasi experimental study non-randomized study with 24 MS patients diagnosed at least 1 year before, and with an EDSS score of under 7. We used the IPPA in 3 groups of eight people in 3 Portuguese hospitals (Lisbon, Coimbra, and Porto). The sessions were held once a week for 90 minutes, over a period of 7 weeks. The instruments used were: We asked the subjects the question “Please classify the severity of your disease?” and used the Personal Wellbeing Scale (PWS) at the beginning (time A) and end (time B) of the IPPA. We used the SPSS version 20. A non-parametric statistical hypothesis test (Wilcoxon test) was used for the variable analysis. The intervention followed the recommendations of the Helsinki Declaration. Results – The results suggest that there are differences between time A and B, the perception of illness decreased (p<0.08), while wellbeing increased (p<0.01). Conclusions: The IPPA can play an important role in modifying the perception of disease severity and personal wellbeing.
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Paper Nr: 46
Title:

Effects of a Neuromuscular Reeducation Program on the Postural Control in Gymnasts with Chronic Ankle Instability
Authors:

Marc Reis, Raúl Oliveira and Filipe Melo
Abstract: Chronic ankle instability (CAI) is associated to the mechanical and/or functional instability of the ankle, being described as often residual change after sprain. Objective: To analyze the effects of a neuromuscular reeducation program for six weeks, in postural sway (PS) and time to stabilization (TS), in functional tests, in asymptomatic gymnasts and in gymnasts with CAI. Methods: The postural variation was evaluated –within sample of 24 gymnasts - 9 with CAI (experimental group) and 15 healthy ones (control group) through a pressure platform, before and after applying the exercise program. Results and Discussion: In the instability group it was observed an improvement in PS and TS in a single limb static stance with open and closed eyes, and after a landing of an anterior jump, medial and lateral side. In the control group a decrease of the PS in a single-limb static stance with eyes open and after the landing of a medial side jump was verified; improvement of the time to stabilization in the landing of lateral and medial side jump, after applying the exercise program. Conclusion: A neuromuscular reeducation program had a positive effect in the improvement of the postural control in gymnasts with or without CAI.
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Paper Nr: 53
Title:

Recent Studies using an Overuse Animal Model Show that Signal Substances are Highly Involved in Muscle Derangement and Muscle Inflammation
Authors:

Sture Forsgren
Abstract: Muscle overuse is a frequent condition accompanying sports-related activities. There is a lack of knowledge concerning the importance of signal substances in situations when overuse leads to markedly affected muscle structure and muscle inflammation. Recent observations on signal substance systems for the muscle tissue in situations with muscle overuse, noted via the use of a rabbit model, are therefore here focused on. The signal substance systems are the tachykinin system, the TNF-alpha system and the glutamate system. The studies have shown that all three systems are involved in the myositis/muscle derangement processes that occur. A central finding is the notion that signal substances in all three systems become locally produced in the muscle tissue and that there is a marked presence of receptors for these in the inflammatory/affected muscle tissue. The relevance of the findings in relation to what is known for the systems and possibilities in treatment regimens are discussed. The findings suggest that signal substances, more than what has been previously considered, should be taken into consideration as factors of relevance in situations when overuse leads to structural derangement and muscle inflammation.
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Paper Nr: 54
Title:

Investigation of the Sensorimotor Training - Analyzing Exercisers with One-dimensional and Multidimensional Instability
Authors:

Angelina Thiers, Annett l'Orteye, Katja Orlowski and Thomas Schrader
Abstract: The importance and the attractivity of the sensorimotor training is still growing. Up to now the impact of the training on the body is not yet fully investigated. Hence, nowadays the planning of the therapy is mainly based on the experiences of the physiotherapist and on the conditions of the practice. For the development of the therapy the physiotherapist is supported by manufacturer’s information about the exercisers as well as by general assumptions regarding the sensorimotor training. For the validation of this information two setups were investigated. In the first part, the behavior of two students was studied on three exercisers. Here the EMG data and the motion data were analyzed. In the second part, the behavior of the left and the right body side was analyzed for 16 subjects. The study revealed that the major work for the maintenance of the equilibrium is done by the distal musculature. Furthermore, it was shown that there is a different behavior of the musculature at both body sides. Additionally, it has been proven that each test person had an individual behavior on the exercisers. Consequently, it would be hard to make general assumptions regarding the impact of the training on the body.
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