Track 6. Sport Biomechanics - Joint ISB Track

4498 Mo-Tu, no. 52 (P61) Biomechanical analysis in the development of a new cardiovascular equipment A. Biscarini 1 , P. Benvenuti 2, F. Cecchinelli 2, S. Zanuso 2. 1Department of Physics, LAMS Laboratory, University of Perugia, Perugia, Italy, 2 Technogym Scientific Department, Technogym S.p.A., Gambettola (FC), Italy

A new equipment, named "Cardio wave", has been developed and optimized to carry out multi-planar exercises that simultaneously combines movements of extension, abduction and external rotation of the hip. Biomechanical modelling was implemented in conjunction with surface EMG and kinematic analysis to calculate and design the optimal 3D inclinations of the device platforms along their curvilinear paths, in order to maintain a correct joint alignment and minimize joint stress within the lower limb, during the whole ROM. For example, at the beginning of the extension phase, the inner side of the platform is higher than the external, avoiding potentially dangerous knee valgus posture and external rotation, and ankle eversion. Actually, in this phase the joint angular acceleration is maximum and the joint stress is higher. During the passive phase, the platform recovery force is finely regulated to avoid abrupt passive flexion movements, while always ensuring the contact of the foot with the platform (absence of impacts). Platform shape and dimensions give a certain degree of freedom to feet placement allowing an individual adaptation while avoiding wrong positions (internal or excessive external joint rotation). The regression line equation that best estimate the intensity-related oxygen consumption was determined and validated by a gas analyzer. By means of Near Infra Red Spectroscopy we assessed the effects of changes in relevant controllable parameters (velocity/resistance levels) and different body positions (trunk bending, handgrip type and forward-backward body weight upset) on the oxidative metabolism of gluteus maximus and rectus femoralis. Combining the results of all the different investigations, we were able to select the optimal working modalities for any specific need and demand. In conclusion, this novel equipment allows joint safe, impact free, multi-planar exercises, which are effective for both strength and cardiovascular training/rehabilitation programs.

6.6 Performance Pattern Variability 6708 Mo-Tu, no. 53 (P61) Finite element analysis of kayak paddle in diverse surface Y.-H. Lin, T.-'~ Shiang, W.-H. Ho. Taipei Physical Education College, Taipei, Taiwan

The aim of this research is about the kayak paddle. Find out the variance of each different pattern paddles in the same condition. We applying "Reverse Engineering" and "3D CAD" to designed three different kinds of paddle sur- faces, and then use the "finite element analysis" to analyze their diversity in the same condition. We completed three fundamental patterns of paddles by using the Reverse Engineering equipment, modify and design various 3D figures of the paddle with "CAD". The three patterns are flat, raised, and guided. Furthermore, we preceded the analysis of hydrodynamics by using the finite element analysis software. First part is to know what distribution of paddle receives force in different flow rates. Second part is about the diverseness, different paddle surface receives different force. We made statistics to the analyze outcome by T-test (u, =0.5). The result shows that the guided surface of the paddle is conspicuously better than the flat and raised one when they are in the different flow rates. (The paddle surfaces have average force: 6.1 g >5.1 g >4.6g). This result offers the consultation to the kayak paddle designers, and expects them to elevate the level of paddle design.

6032 Mo-Tu, no. 54 (P61) Estimation of the quantification of the elastics loads on the jump fit circuit P.E. Schiehll, L.A. Peyr6-Tartaruga, G. de Matos Zingano, J. Fagundes Loss. Exercise Research Laboratory, Rio Grande do Sul Federal University, Porto Alegre, RS, Brazil

The aim of this study is to present a prediction model of the Jump Fit Circuit elastics loads. This is the first study regarding load estimation in a Jump Fit Circuit class. Six workout teachers executed exercises with the upper limbs using elastics tubes on a mini springboard. Four Circuit Kit composed of several elastics tubes (with different sizes and formats) were used with different loads. Each elastic tube was equipped with one load cell. The load cell was then calibrated to obtain the angular coefficient therefore allowing the conversion of the results from mV to Kgf. Afterwards a measure tape was used to measure the variation of the deformation of each of the elastics tubes. The tubes were deformed up to 3 times of their original length. These measurements were taken on two phases (beginning and end) of each of the following exercises: Biceps, French Triceps, Triceps, Unilateral Kickback, High Pull, Back Stroke and Military Press. The regression coefficients (R 2) obtained varied between 0.91 and 0.98. Through these deformation parameters, one could estimate the force [Kgf] of the localized exercises in a Jump Fit Circuit class. The

6.6 Performance Pattern Variability $555

loads offered in the Jump Fit Circuit exercises were influenced by the type of elastic tube and also by the stature of the executor. The black elastic tube was the one that provided the major resistance during the performance of the mentioned exercises. The foremost contribution of this data is to enable workout teachers to elaborate a progression of their students' trainings and to program the intensity of the loads. This project was supported by the American Medical do Brasil Ltda.

4874 Mo-Tu, no. 55 (P61) Analysis of the neuromuscular control in a rowing specific force endurance test - an approach to evaluate inter-subjective variability of test results L. Janshen 1 , K. Mattes 2. 1Institute for Sport Science, Humboldt-University Berlin, Germany, 2Faculty of Education, Psychology and Human Movement, University of Hamburg, Germany

In this study the activity of the upper arm, shoulder and lower back muscles was investigated during an exhaustive rowing specific weight lifting test to analyse (1) differences in coordination strategies over time between subjects and (2) changes in neuromuscular parameter and in the coordination pattern over time for each subject. Seven female subjects, recruited from the national rowing team of Germany, placed in a prone position on a horizontal board, lifted a mass of two third of their one repetition maximum at a fixed frequency of 0.5Hz until complete exhaustion. Staring with fully stretched arms, the mass had to be moved vertically upwards from the floor, until the barbell made contact with the board. Frontal and side view video was recorded to identify angular motion of the elbow, shoulder and thoracolumbar junction. Myoelectric signals were recorded (1000 Hz) using bipolar surface electrodes. Analyzed EMG parame- ters included duration of activity, root mean square (RMS), integrals (iEMG). In addition median (MF) and mean power frequency (MPF) were analysed using DFT. Three subjects performed the required 210 repetitions. The others managed 180, 160, 128 and 119 repetitions respectively. Comparing subjects, no signifi- cant differences in joint excursions or EMG parameters could be observed over the first 30 repetitions. Subsequently, three different coordination strategies with varying time curves of the EMG parameters were observed. During the lifting task all subjects demonstrated significantly increasing activity duration which in turn led to decreasing resting times to keep the required lifting frequency. Six subjects showed significantly decreasing MF and MPF together with significantly increasing RMS and iEMG values for the upper arm muscles. Two of these subjects probably managed to compensate for this muscle fatigue by using the shoulder and lower back muscles respectively. Here, increasing MF, MPF, RMS and iEMG values were observed. The approach of this study may help to evaluate and optimize the comparability between subjects under standardized test conditions.

5501 Mo-Tu, no. 56 (P61) Developmental stages of musical skill of samba

T. Yamamoto, K. Ishikawa, T. Fujinami. School of Knowledge Science, Japan Advanced Institute of Science and Technology, Ishikawa, Japan

Through our study of motor skill development, we hypothesize that timing information is most important information for motor control. Skill of playing music is a mean for understanding how timing information is represented in the motor skill. In this work, we adopted samba as the task. Since samba is not familiar to Asian people and clear difference according to skill level is expected to seen. Five healthy male subjects (one professional and four amateur musicians) participated to the motion capture experiment where the subjects to play the shaker in samba rhythm in various tempo (60, 75, 90, 105 and 120bpm).We analyzed movements of the shaker with respect to the periodicity and existence of an accent. While the former is common to all music, the latter is specific for samba, with rapid pattern, "Da-Du-Du-Da", where "Da" is strong and "Du" is weak sound. Strength of the sound corresponds to acceleration, which roughly corresponds to amplitude of oscillation because of almost equal temporal spacing. By calculating autocorrelation of shaker position on the sagittal plane, we found that overall periodicity is kept for all subjects. However, as for accent, it is not always seen while it is obviously seen in the professional. We also did experiment of skill development of samba dancing. Two subjects without former experience of samba participated. They attended weekly danc- ing course and monthly motion capture measurement for four months. Analysis of autocorrelation of the vertical position of the hip showed that accent is obtained though the training. This result implies that timing information for controlling can diversify with an accent after single-cyclic periodicity is obtained.