ISBS (International Society of Biomechanics in Sports): Conference Proceedings Archive
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USING BARBELL KINEMATICS TO PROVIDE THE COACH WITH THE FEEDBACK FOR THE SNATCH
Get PDFThe purpose of this study was to use three dimensional kinematics of the barbell to provide the coach with quick feedback for the snatch technique of an elite Taiwanese female weightlifter. Three high speed cameras were used to simultaneously record the barbell movements with film frequency of 200 Hz. The horizontal dispalcement-velocity relationship of the barbell seemed to have varied in a certain range while lifting a 95kg barbell. Based on these results, it was recommended the lifter attempt 95kg for her first attempt in the competition. In conclusion, the barbell kinematics is a quick and easy approach to provide the coach with feedback for the snatch. The information of trajectory and movement characteristics of the barbell could provide the coach and the lifter to assist in improving the lifter’s snatch technique
BASEBALL FEET-FIRST SLIDING TECHNIQUE
Get PDFThe purpose of this current study was to investigate the difference of planned and unplanned baseball feet-first sliding techniques. Five male collegiate baseball players (NCAA II) were recruited. Each subject performed 3 successful trials of regular running, planned, and unplanned baseball feet-first sliding techniques to the third base. 3D motion analysis was used to obtain kinematic data during the last 25 feet (7.62 m) of the performance before contacting the third base. Results showed planned sliding technique had significant longest time when compared to unplanned and regular running to the base (P < 0.01). Running to base had significant greater average horizontal velocity than both sliding techniques (P < 0.01). Additionally, unplanned sliding technique had greater average horizontal velocity than planned sliding technique (P < 0.01)
COMPARISON OF ACCELEROMETRY STRIDE TIME CALCULATION METHODS
Get PDFThe purpose of this study was to investigate how a newly proposed method of stride time calculation, utilising data filtered at 2 Hz, compared to previous methods. Tibial accelerometry data for 6 participants completing half marathon running training were collected. One run was selected for each participant at random, from which five consecutive running strides were ascertained. Four calculation methods were employed to derive each stride time and results were compared. No significant difference was found between methods (p=1.00). The absolute difference in stride time, when comparing the proposed method to previous methods, ranged from 0.000 seconds to 0.039 seconds. Filtered data could offer a simplified technique for stride time output during running gait analysis, particularly when applied during automated data processing for large data sets
THE ATTRACTOR METHOD – A TECHNIQUE TO QUANTIFY DIFFERENCES OF CYCLIC PROCESSES AND THEIR VARIABILITY
Get PDFThe purpose of this study is to introduce a new, very sensitive method to quantify differences of movement pattern and the variability of cyclic processes. While the method is applicable to practically all cyclic processes, we restrict ourselves to an example of walking under various conditions
INFLUENCE OF BODY SEGMENT INERTIA PARAMETERS ON UNCERTAINTIES IN JOINT SPECIFIC POWER DURING SPRINT CYCLING: A MONTE CARLO SIMULATION
Get PDFJoint-specific power analyses are important in the assessment of cycling biomechanics but they contain uncertainties due to errors in input parameters. The aim of the study was to investigate the effect of uncertainty in body segment parameters on joint-specific powers during maximal sprint cycling, using a Monte Carlo analysis. Joint powers were estimated using standard inverse dynamics techniques, with body segment parameters and uncertainty in these inputs defined using reference data. Monte Carlo simulations (10,000 iterations) were performed for pedal cycles at 120 rpm and 160 rpm. The analysis highlighted practically relevant uncertainties in peak hip joint power at racespecific pedalling rates caused by uncertainty in body segment parameters
IMPACT OF STRENGTHENING EXERCICES ON THE SHOULDER JOINT
Get PDFStrengthening of shoulder muscles in rehabilitation protocols and sport practice can be achieved by a wide range of different exercises. Very limited objective data is at disposal to emit recommendations for design of a training protocol that aims at minimizing subacromial impingement, stress on the articular cartilages or labrum and excessive tendon elongation of the rotator cuff. The purpose of this study was to evaluate the impact of shoulder rehabilitation exercises on the shoulder joint using motion capture and computer simulations of patient-specific anatomical joint structures
MUSCLE RECRUITMENT SEQUENCE AND TOTAL REACTION TIME DURING A KARATE ROUNDHOUSE KICK
Get PDFThe purpose of the current study is to quantify the muscle recruitment sequence and total reaction time of fourteen national karate athletes and fourteen college karate athletes while performing upper level roundhouse kick. A 16-channel electromyography was used to measured the muscle activities and an instrumented target was for the evaluation of the response time. The experimental results show that both groups recruited the biceps femoris on the kicking (right) side, followed by the right gastrocnemius, but the subsequent muscle firing sequence was slightly different. This resulted in smaller total reaction time of the national group (736.32 ms) than the time of the control group (770.28 ms) because of different across skill level
INFLUENCE OF GENETIC VARIATIONS IN PHYSICAL FITNESS
Get PDFOlder population has increased and presents reduced physical fitness. On the other hand, it is known that genetic variants can explain these declines. The aim of this study was evaluate the effect of ACE ID and ACTN3 R/X polymorphisms in body fat and physical capacities in old women. 66 old women were genotyped to ACTN3 and ACE polymorphisms and submitted to anthropometric measurements, physical tests, IPAQ and a questionnaire related to food intake. For the ACTN3 genotype, XX group presented reduced levels of upper limb flexibility and cardiorespiratory capacity. Related to ACE genotype, ID group demonstrated increased cardiorespiratory capacity and decreased body fat percentage. There was no statistical difference in the other variables. In the future, data like these will enable each person have his/her intervention focused in that variables with more genetic potential to decline
SUBJECT-SPECIFIC MUSCULOSKELETAL MODEL TO IDENTIFY MUSCLE CONTRIBUTION TO THE ACCELERATION PHASE IN ELITE SPRINTING
Get PDFThe purpose of this study was to identify which lower limb joint moments of force and lower limb muscles had the highest contribution to the forward and upward acceleration of the Body Centre of Gravity (BCG) in an elite sprinter during the first step after starting from blocks in 100 meters dash. An induced acceleration analysis approach was used to mechanically ascertain this contribution. Two models were used, one based in a simple multilink rigid body’s model and a second using a musculoskeletal model developed using Opensim. Our results showed a possible synergist action between hip and ankle extensors that allow an optimal combination that resulted in a forward propulsion of the BCG, this results seem to be corroborated using an Opensim musculoskeletal model
DOES THE SITTING POSITION INFLUENCE CLAY TARGET SHOOTING PERFORMANCE IN ATHLETES WITH A MOTOR IMPAIRMENT?
Get PDFOlympic trap clay target shooting (CTS) is currently performed by motor impaired individuals (MII), but not yet included in the International Paralympic Committee endorsement. This study aimed at supporting the development of a classification model that divides athletes competing in standing and sitting postures. Two groups of 5 standing and 5 sitting MII athletes were recruited for an instrumented CTS task execution. During competition, sitting athletes showed a lower rate of success with respect to the standing ones only for targets requiring wider ranges of motion, possibly due to fatigue. Their predominant use of upper body movements implies an adapted technique to reach a good performance, testified by a smoother movement, a lower peak accelerations at the gun tip, a smaller range for all absolute and relative rotations, and a different muscle activity