ISBS (International Society of Biomechanics in Sports): Conference Proceedings Archive
Not a member yet
5464 research outputs found
Sort by
A PRELIMINARY STUDY OF BREAST MOVEMENT IN DIFFERENT BRA SUPPORT
Get PDFTo free women involved in physical activities from suffering breast pain due to insufficient breast support, thorough understanding of the breast displacement mechanism is needed. The study is aimed to determine the true movement of the breast in three types of bras, and ultimately, to build a scientific base for bra design improvement. 28 female participants were recruited and the breast movements in four different types of breast support were recorded using the electromagnetic tracking system for further analysis. The results showed that the trajectories of left and right breast in a crop-top bra for the lateral raise showed significant difference (p =.039). The effect of sportsbra was obvious in all four movements and the breast displacement decreased as the breast support level increased (from non-sportsbra to sportsbra)
EFFECT OF SAUNA WARM-UP ON OVERHEAD SQUAT DEPTH IN ELITE WEIGHTLIFTERS
Get PDFAmple total body flexibility or range of motion is important in Olympic style weightlifting. Although research has been conducted to study flexibility, little information exists regarding the use of saunas as an alternative modality for increasing flexibility. The objective of this study was to explore the effects of a fifteenminute sauna session on overhead squat depth in 15 elite Olympic style weightlifters. Range of motion was assessed via video camera during a control and treatment session (3 trials at 4 time points). Overhead squat depth displayed excellent within- and between-session reliability. Repeated measures ANOVA revealed no significant changes in overhead squat depth following the sauna treatment (p > 0.05)
ASYMMETRY ANALYSIS OF CROSS ON GYMNASTICS TRAINING AND COMPETITION RINGS
Get PDFBased on biomechanics and the principles of training specificity, the purpose of this study was to verify whether the use of a training device is a specific drill to the static cross posture on rings. Six elite Brazilian gymnasts performed the cross on competition and training rings. Variables analysed from digitised video data were right and left shoulder angles in the frontal plane. Larger angles were found when performing the cross on training rings for right (RMSD 3.20°) and left (RMSD 3.27°) shoulders. Less inter-limb asymmetry was also reported for the training rings (1.87%), compared to the competition (2.25%) condition. The training device seems to allow elite gymnasts to reduce shoulder asymmetry and deviations from 90° whilst performing the cross, which can lead to execution penalties in competition
KINETIC AND KINEMATIC COMPARISON OF ALPINE SKI RACING DISCIPLINES AS A BASE FOR SPECIFIC CONDITIONING REGIMES
Get PDFThe purpose of this preliminary case study was to compare the alpine ski racing competition disciplines slalom and giant-slalom with respect to principal kinematics of the lower limbs and the acting forces. Knee angles and ground reaction forces of one high level athlete were determined using inertial sensors and pressure insoles, respectively. Slalom was characterized by a “high dynamic skiing mode” with a distinct “knee angle and loading synchronism” between the inside leg and the outside leg. For giant slalom, a polarized situation was observed: “higher quasi static loads at high knee angles” on the outside leg and “lower eccentric-concentric loads at low knee angles” on the inside leg. These findings may help to increase the specificity of conditioning training and developing more discipline-specific exercises
ELEVATED TRACK IN POLE VAULT, WHAT ADVANTAGE FOR RUN-UP DETERMINANTS OF PERFORMANCE?
Get PDFThe aim of the present study was to compare high-level pole vault performances set in standard versus elevated tracks during official competitions, with a specific focus on the mechanical determinants of the run up phase such as speed, contact time, step frequency, lower-limb stiffness and take off position. The main variables that were significantly correlated to a benefit from elevated tracks on run-up speed were speed on a normal track, step frequency, percent change in contact time and step frequency. The use of indoors elevated track in high-level to world-class athletes did not result in systematic increase in the main performance determinant, i.e. run-up speed. However, the individual changes analysis shows that slower athletes with lower step frequency are those who benefit the most from the use of elevated track
EFFECT OF FOOT STRIKE PATTERN ON AXIAL AND TRANSVERSE SHOCK SEVERITY DURING DOWNHILL TRAIL RUNNING
Get PDFThe purpose of the present study was to investigate the influence of foot strike pattern (FSP) on shock severity and attenuation during a downhill trail run. Twenty-three runners performed a 6.5-km downhill run (-1 264 m) equipped with four tri-axial accelerometers placed at tibia, sacrum, heel and metatarsals. FSP was identified using time difference between heel and metatarsals peak accelerations. Peak accelerations, median frequencies, and shock attenuation were calculated from tibial and sacral axial, anteroposterior and resultant accelerations over six sections during the run. Linear regressions analysis revealed that FSP affected differently the components of shock acceleration, i.e. although anterior FSPs enlarged shock severity along the tibial axial axis, they lowered shock severity along the tibial and sacral antero-posterior axis
JOINT WORK OF THE TAKE-OFF LEG DURING ELITE HIGH JUMP
Get PDFThe purpose of the study was to evaluate kinematics and kinetics in elite high jumpers and to estimate joint work of the lower extremity with a custom-modified full-body model. Motions of seven male athletes (personal best 2.24 ± 0.06 m) during jumping were filmed with 19 Infrared-Highspeed-Cameras and ground reaction forces were captured with a force plate. The results show that knee joint energy absorption is twice as much as at the ankle joint (p 0.05) in energy generation between the knee and ankle joint, but the ankle joint generates more energy than it absorbs (p < 0.05). The problem-solving approach to raise the center of mass to 2.10 m was different between the jumpers
COMPARISON OF PULL AND CATCH PHASES DURING CLEAN EXERCISESE
Get PDFThe purpose of this study was to identify differences in kinetic characteristics between the performed the PC at 30%, 60%, and 90% of one repetition maximum. Kinetic data were collected from recorded data by using a Vicon motion system and force platforms. In the comparison between the pull and catch phases, the kinetic characteristics of the catch phase were as follows: 1) The peak ground reaction force did not significantly differ according to load. 2) Ankle and knee kinetics showed large values. 3) The force and power in the ankle and knee did not significantly differ between the light load (30%) and heavy load (90%). Therefore, the importance of using PC in training not only for the pull movement but also for the catch movement
DYNAMIC CONTRIBUTION ANALYSIS ON THE PROPULSION MECHANISM OF SPRINTER DURING INITIAL ACCELERATION PHASE
Get PDFThe purpose of this study was to propose a method that quantifies the functional roles of the support leg joint torques during sprinting acceleration phase. The acceleration of whole-body centre of gravity caused by the joint torques at 1st, 3rd, 5th and 7th steps from the crouch start were calculated based on the equation of motion for the whole body modeled as a linked system of fifteen rigid segments. The generation mechanism of eccentric ankle joint torque was quantified as the contributions of joints torques to the generations of joint angular velocities. The results indicate that 1) the eccentric plantarflexion torque is the largest contributor to the whole-body propulsion, 2) the eccentric plantarflexion torque is generated by the torques of hip and knee joints, and 3) the step number influences the propulsion mechanism
GENERATING AND APPLYING KNOWLEDGE IN SPORTS BIOMECHANICS: EXAMPLES FROM ROWING AND RUNNING
Get PDFSometimes new knowledge, gleaned from our biomechanics experiments, is surprising, even counter-intuitive. Some examples from rowing and footwear biomechanics research illustrate this phenomenon. A study of ergometer rowing reveals a flexion moment at the knee joint while it is extending during the drive phase with implications for strength and conditioning. On-water rowing measurements of rower power output underline the importance of recovery phase technique. Observations of multi-segment foot motion while running have exposed the barefoot as a flexible power generator, raising questions about the efficacy of footwear. These experiences, surprising at their time, were signs of pushing the envelope and fine tuning of our models