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PUNT KICK MOTION FOR RUGBY PLAYERS WITH DIFFERENT KICKING SKILLS
Get PDFThe purpose of this study was to compare the punt kicking motions for different kicking distances in the college and professional rugby players. Three-dimensional coordinate data were collected from nine college rugby players and six professional players. They were asked to performed three different punt kicks aiming at 35-m, 50-m and maximum (MAX) kicking distances. The approach angle varied with the kick distance in both groups. For the 35-m kick, all players used a straight approach heading to kicking direction. For the 50-m and MAX kicks, they approached to the ball diagonally, which helped to increase the hip rotation range to acquire larger swing speed
EXPLORING THE INFLUENCE OF FEMUR BONE ANATOMICAL VARIABILITY ON CAM MORPHOLOGY
Get PDFThe purpose of this study was to identify potential femoral geometrical risk factors on cam morphology development and its implications for athletes. 382 segmentations from CT-scans were analysed. Cam morphology was defined by an average distance deviation (ADD) between a healthy fit onto the proximal femur and the segmented proximal femur at the anterolateral head-neck junction and categorized into four groups. Neck-shaft angle, femoral anteversion, neck length and femur length described the femur geometry. Neck-shaft angle demonstrated a significant effect on the ADD. Additionally, a novel method for automatically characterizing femur morphology was developed, offering potential applications in diagnosing cam deformities. The findings suggest that the neck-shaft angle may serve as a risk factor in the development of cam morphology
TIBIAL LOAD IN RUNNERS WITH A HISTORY OF BONE STRESS INJURY: A CASE CONTROL STUDY
Get PDFThe purpose of this study was to identify differences in tibial bone load during running in subjects with a history of bone stress injury (BSI) as compared to healthy controls. Subjects with a recent history of tibial BSI (n=3), \u3e1 year since tibial BSI (n=3), and healthy controls (n=3) ran on an instrumented treadmill while motion capture data was collected. Mixed model ANOVA (p1 year since tibial BSI. While a relationship between time and bone load post tibial BSI is possible based on the results of this study, additional studies are essential to confirm this association and progress our understanding of running biomechanics following BSI
IMU ACCELERATION DATA DIFFERS BETWEEN THE FRONT AND REAR FOOT IN SNOWBOARD FREESTYLE
Get PDFThe purpose of this study was to compare acceleration data from front and rear foot IMUs of elite snowboard halfpipe riders to gain insights towards IMU driven motion analysis and event detection. Utilizing IMUs attached to riders\u27 boots, the research found varying time offsets and correlations across different axes. The findings show that IMU placement and orientation play a crucial role in accurately capturing snowboarding dynamics. The study contributes to the potential use of IMU data for enhancing motion analysis and feedback systems in snowboard freestyle
CALCULATION AND EVALUATION OF A THREE-DIMENSIONAL FORCE FOLLOWING BOXING PUNCHES ON A DUMMY HEAD
Get PDFThe current study evaluates an approach that estimates the 3D force acting on a dummy\u27s head and neck construct following boxing punches. The calculation refers to marker-based kinematic measurements, and incorporates the head mass and the estimated effective mass of the striking hand. A total of 2040 punches were compared with measured force values of a six-axial load cell in the upper dummy neck regarding peak force (peakF) and rate of force development (RFD). The two random effect regression models revealed that the calculated force values could significantly predict the measured force values. The results showed reasonable effective mass estimates (2.04±0.41kg) and plausible force values (peakFMoCap = 268.82 ± 83.89N). Ultimately, this approach can be used in real boxing scenarios and enables analysing the loads in the head and neck region by implementing the punch force estimates and the head kinematics into a musculoskeletal multibody model
GAIT EVENT DETECTION DURING WALKING USING DEEP LEARNING AND THIGH-WORN ACCELEROMETRY
Get PDFMobility and gait are important indicators of human health. However, measuring them outside of a laboratory setting can be challenging. To measure human physical behaviour in free-living conditions, thigh-worn accelerometers and data-driven algorithms are commonly used. This study explores a deep learning approach that utilises data from a single thigh-worn accelerometer. A temporal convolutional network was trained to predict gait events in healthy adults during various walking conditions. The model demonstrated a high level of detection accuracy (F1 score ≥ 99%) and good time agreement for both gait events, with the 95% limits of agreement being -0.04s and 0.04s. Minor differences in spatiotemporal gait parameters were observed. The results indicate the potential of using a deep learning approach with thigh-worn accelerometry data for future research
SEGMENTED EVALUATION OF CENTER OF MASS PATTERN SMOOTHNESS THROUGHOUT STEP AEROBICS TRAINING AS A MEASURE OF TRAINABILITY
Get PDFTrainability is a dynamic phenomenon that measures the changes in trainable factors over time. The current study examines whether smoothness evaluation could be considered as a measure of trainability. To this effect a group of nine middle-aged females (average age: 53.38 yrs, average BMI: 24.45kg/m^2 ) were asked to perform step aerobics training for 24 sessions and their kinematic data were captured using an IMU. The smoothness analysis aimed to analyze each step separately using continuous wavelet transform. Jerk cost changes, as an evaluation of smoothness, in 24 sessions in backward direction magnified the differences between the two steps. Lack of symmetry in the smoothness results, indicating that CNS attention is all focused on the leading step to ensure initial stability. To enhance the trainability it is advisable to alternately change the leading step
FACTORS INFLUENCING SINGLE LEG VERTICAL JUMP PERFORMANCE IN ACLR PATIENTS
Get PDFThis study explores the differences in jump strategy and strength characteristics between athletes who do and do not achieve adequate symmetry in single-leg countermovement jump (SLCMJ) performance following Anterior Cruciate Ligament Reconstruction (ACLR). Including 372 male athletes recovering from primary ACL injuries, the study utilizes independent sample t-tests and regression models to analyze strength and key jump variables. Our findings reveal key differences in knee extensor strength and jump metrics for the involved limb despite no differences in uninvolved limb jump height. These results highlight the significance of SLCMJ testing in ACL rehabilitation, providing valuable insights into patient functional status. This approach can be instrumental in developing targeted rehabilitation strategies, thereby enhancing recovery outcomes post-ACLR
REGIONAL MUSCLE ACTIVATION OF THE BICEPS FEMORIS
Get PDFThe purpose of this study was to examine regional BFlh activation during isometric knee flexion. Using an isokinetic device and high-density EMG, 11 males performed contractions at all combinations of short, medium and long MTU lengths and three torque levels (30%MVC, 60%MVC, 90%MVC). Distal BFlh exhibited significantly higher activation at 60% MVC and 90%MVC than proximal, indicating intensity-dependent heterogeneity. No effects of muscle length on muscle activation were found. Additionally, the findings suggest BFlh operates on the ascending limb of the force-length relationship. Practitioners should be mindful of potential intramuscular variations in biarticular muscles during different contraction circumstances with potential implications for hamstring injury risk assessment and exercise selection
CAN IMUS ACCURATELY DETECT DIFFERENCES IN DYNAMIC CONSTRAINT-GOVERNED TASKS? APPLICATION TO THE LAYUP SHOT IN BASKETBALL
Get PDFThe purpose of this study was to assess the validity and reliability of an inertial measurement unit (IMU) system against an optical motion capture system during a dynamic complex task, the layup shot in basketball. Eight basketball players performed 10 trials with and 10 without a defender. Key kinematic variables (jump height, take-off angle, joint angles, COM displacement) were derived and agreement (Bland-Altman plots) and disagreement (RMSE, SPM) calculations were carried out for each trial. The IMU system provided agreeable results for jump height and take-off angle, while joint angles and COM displacement agreement were plane-specific. A between-condition analysis demonstrated the IMUs reliably detect joint angle differences between defended and undefended conditions comparable to the optical system for all but three joint angles. The IMU system was able to detect similar difference between conditions to the motion based system