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IN-FIELD BIOMECHANICS OF HALFPIPE SNOWBOARDING: A PILOT STUDY
Get PDFThe aim of this pilot study is to develop a method to measure the sport-specific biomechanics of the Olympic discipline of halfpipe snowboarding. An integrated fusion approach using a global navigation satellite system, inertial measurement units, and an insole system to analyse the athlete\u27s position, movements, and forces transmitted to the board was proposed. To test the feasibility of this method a former European Cup athlete (n=1) performed 32 jumps (16 front- and backside airs) in four runs. The method provided uninterrupted measurement over extended periods of time with minimal distortion to the athlete and plausible results (COM velocity: 5.0±0.5 m/s - 13.0±0.4 m/s, back leg knee flexion: 29±2° - 64±4°, peak rear foot load: 1269±123 N). In summary, the method was feasible to capture sport-specific biomechanics of halfpipe snowboardin
DO FEMALE WEIGHTLIFTERS SNATCH DIFFERENTLY? ANALYSIS OF BARBELL KINEMATICS USING STATISTICAL PARAMETRIC MAPPING
Get PDFThis study aimed to analyse gender differences in barbell kinematics of the snatch in international elite weightlifters. At the 2019 Senior World Championships, horizontal and vertical barbell kinematics of the 1RM snatch lifts of the top 5 female and male weightlifters of all 10 body weight categories were assessed using two-dimensional video analysis (50 Hz). Gender differences were analysed for kinematic time series data using statistical parametric mapping. Results revealed almost similar mean snatch barbell trajectory and velocity pattern for female compared to male weightlifters. Significant differences were detected during the 1st pull with lower barbell distance and velocity. However, the few sex differences may be attributed to the high variability of barbell kinematic parameters, which are due to the dependency on body weight
USEFUL KICKING FOOT BEHAVIOR OF SOCCER INSTEP KICKING TO LAUNCH THE BALL IN VARIOUS DIRECTIONS
Get PDFThe present study aims to illustrate the distinct characteristics of foot motion at ball impact, manipulating various ball launch directions. Seven experienced male university players conducted a total of 126 trials of soccer instep kicking, targeting three areas of the soccer goal. Three ultra-high-speed cameras recorded the ball impact aspect at 2000 Hz. We computed the foot contact point, the foot instep direction, and the foot swing direction. The multiple regression model demonstrated that the variance of ball launch directions was explained significantly by the foot contact point and the foot instep direction, while the foot swing direction was not. This result suggested that the foot contact point on the ball and the instep facing directions must be controlled appropriately to facilitate players to kick the ball in the desirable directions
FEMALE ATHLETES ARE AT HIGHER RISK TO SUFFER ANTERIOR CRUCIATE LIGAMENT RUPTURES DURING THE OVULATORY PHASE OF THEIR MENSTRUAL CYCLE
Get PDFThis study examined the effect of the phase of the woman’s menstrual cycle on the rate of injuries of the anterior cruciate ligament. 39 females completed a questionnaire asking for the phase of their menstrual cycle, in which their most recent anterior cruciate injury occurred. A chi-square test revealed that the phase of the menstrual cycle has a significant effect (p \u3c 0.001) on the aforementioned injury rate. During their ovulatory phase, women are at 4.33-times higher risk of suffering an anterior cruciate ligament rupture, while all other phases of the menstrual cycle show a less than statistically expected risk of anterior cruciate injury. We hence suggest that the participation in risk related sports should be carried out with reduced intensity or adjusted training content to avoid injuries of the anterior cruciate ligament during the two days of the ovulatory phase of a woman’s menstrual cycle
COMPARISONS OF GROUND REACTION FORCES BETWEEN TWO DIFFERENT 180-DEGREE TURNING TECHNIQUES IN FEMALE CRICKETERS
Get PDFChanging direction (COD) particularly a 180-degree turn is a key skill in cricket. Two different techniques, Half-half turning (HH) and sprinting (SP) are commonly performed by cricketers. HH is also known as side-lunging turn whereas the SP involves a slight jump during the turn, followed by landing in a sprinting stance. The aim of this study was to compare kinetic differences between the two techniques. In this study, ground reactions forces (GRF) of three successive foot contact before turning were focused. Nine Thai national female cricket players who familiar with both techniques volunteered in this study. Participants were instructed to perform 180-deg turning techniques while holding a bat on a track with embedded force platforms. There trials of each technique were collected. GRFs and contact time (CT) at the three-foot contact events; antepenultimate (AFC), penultimate (PFC), and final (FFC) were analysed. Paired t-tests were employed to determine difference between the two techniques. The results showed that all GRFs of SP at AFC are significantly higher than HH (
FOREFOOT BENDING STIFFNESS IN THE BOBSLEIGH PUSH-START
Get PDFThe purpose of this study was to investigate how forefoot bending stiffness (Kcr) changes with speed across the bobsleigh push-start. Kinematics and kinetics of 15 elite athletes were measured on an indoor track during different phases (Contact 1 & 2, 10 m, 30 m) of the bobsleigh push-start using a MoCap-System and three force plates. Metatarsophalangeal joint (MPJ) angles, moments and Kcr were calculated via MATLAB. In contrast to sprinting, maximum MPJ moments, moments at maximum MPJ dorsiflexion and Kcr showed no significant differences (p \u3e 0.05) about the push-phase due to the inter-individual variations between the athletes. The forefoot mechanics of each athlete should be taken into account individually for performance enhancement strategies and the development of assistive devices like insoles or customized shoes
TECHNICAL EVALUATION OF THE FIDELITY OF THE HTC VIVE FOR UPPER LIMB TRACKING
Get PDFNovel tracking technologies targeting non-technical users enabled the creation of accessible motion tracking for medical functional evaluation and assisted rehabilitation. Here we describe the adaptation of the HTC Vive tracking technology toward this goal. The resulting system was then tested comparing three different anatomical calibration methods, accounting for inter-subject (1 female, 2 male) and inter-operator (2 experienced, 3 inexperienced) variability, as well as six different methods for spatial alignment with the reference measurements system. Accuracy and precision of our methods were quantified by comparison with Vicon optical tracking system. The accuracy of the anatomical landmark tracking was 2.3 ± 0.5 cm with the cleanest protocol tested. Inter-operator variability caused significant changes in measurement errors, while inter-subject variability did not
THE INFLUENCE OF NOISE IN ANGULAR KINEMATICS ON THE TRANSFORMATION OF LINEAR ACCELERATION BETWEEN ACCELEROMETER COORDINATE FRAMES
Get PDFLinear accelerations measured by instrumented mouthguards (iMG) are transformed to a common reference frame. To investigate the influence of signal noise on this transformation using ground truth measurements, this study transformed linear accelerations measured by an Anthropomorphic Test Device (ATD) to the iMG frame. Noise was incrementally added to ATD angular velocity signals across 81 impacts. Agreement was quantified between ATD ground truth versus noisy angular velocity, angular acceleration and transformed linear acceleration signals. Angular velocity noise as low as 0.265 rad/s led to errors exceeding 10%, highlighting the transform’s sensitivity to angular kinematics. The findings highlight potential difficulties in accurately interpreting noisy iMG data, stressing the necessity for precise processing techniques to ensure reliable biomechanical analysis
UNDERGRADUATE STUDENTS\u27 PERCEPTIONS OF A PROBLEM-BASED LEARNING BIOMECHANICS MODULE
Get PDFThe purpose of this study was to explore student perceptions of problem-based learning and provide recommendations for practice. Five students enrolled on a 2nd year sports biomechanics module at a UK institution participated in semi-structured focus groups at the mid- and endpoints of the module. Thematic analysis, with an inductive focus, identified themes related to successes, challenges and recommendations. Successes included intellectual development, teamwork and inclusivity. Challenges included uncertainty, engagement and retreat in intellectual development. Recommendations were integration of some traditional methods and choice of assessed problems. Educators can be confident that problem-based approaches can develop desired skills for practice but should be conscious of their students\u27 stage of intellectual development
ALTERATIONS IN MUSCLE SYNERGIES IN PATIENTS WITH KNEE OSTEOARTHRITIS DURING LEVEL- AND DOWNHILL WALKING
Get PDFIn this study, the effects of knee osteoarthritis (KOA) on muscle synergy composition during locomotion tasks were investigated. Utilizing non-negative matrix factorization on surface electromyography data from 37 participants, analyses of muscle synergies in both level walking and ramp descent in KOA patients and age-matched controls were conducted. It could be shown that KOA affects muscle synergies in the affected limb during level walking, where a merge of synergies during late swing and early stance phases is observed. A similar effect was observed in ramp descent for the affected and unaffected limb. In this study, the impact of KOA on muscular coordination across locomotion tasks is depicted, and it is suggested that muscle synergy analysis can serve as a useful biomarker, e.g. in the assessment of therapeutical interventions