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DIFFERENCES IN INTRA-FOOT MOVEMENT STRATEGIES DURING THE CUTTING TASK AMONG CAI, COPERS, AND HEALTHY INDIVIDUALS
Get PDFIndividuals with chronic ankle instability (CAI) suffer from the resulting sequela of repetitive lateral ankle sprains (LAS), whilst copers appear to cope with initial LAS successfully. Therefore, the aim of this study was to explore the intra-foot biomechanical differences among CAI, copers, and healthy individuals. Twenty-two participants per group were included and required to perform a cutting task. A five-segment foot model with eight degrees of freedom was used to explore the intra-foot movement among these three groups. Joint moment differences were not found among these three groups, however, Copers presented greater eversion angles compared to others. Copers rely on more eversion positioning to prevent over-inversion of the subtalar joint compared to CAI. These findings may help in designing and implementing interventions to restore functions of the ankle joint in CAI individuals
JY61 IMU SENSOR EXTERNAL VALIDITY: A FRAMEWORK FOR ADVANCED PEDOMETER ALGORITHM PERSONALISATION
Get PDFThis case study aims to compare a low-cost inertial sensor prototype (JY61 IMU + ESP8266 MCU designed for real-time non-proprietary data streaming over Wi-Fi) with a high-end mobile (iPhone 13 Pro Max) using Matlab pedometer algorithm. Preliminary experiments used data collected at 100 Hz including 20, 50, and 100 steps on a partially carpeted and partially hard floor surface with the test subject wearing high heels and tennis shoes. The error comparison between the sensor (0–1%) and high-end mobile (0–2%) suggests that the sensor can be used as a privacy-preserving pedometer which is smaller, lighter and a low-cost alternative to mobile sensors. The experimental framework developed for advanced pedometer personalisation is applicable in education, gate pattern analysis and other sensor advancements for sport equipment and wearable technology applications
TOWARDS REAL-TIME ASSESSMENT: WEARABLE-BASED ESTIMATION OF 3D KNEE KINETICS IN RUNNING AND THE INFLUENCE OF PREPROCESSING WORKFLOWS
Get PDFThis study aimed to estimate knee kinetics in recreational runners during treadmill running based on seven IMUs and pressure insoles using convolutional neural networks (CNN) with two input segmentations. Ground-truth knee moments of 19 runners during sloped and level treadmill running were calculated by conventional lab-based methods. We trained two CNNs on (1) step-segmented and (2) continuously windowed inputs and investigated differences in their joint moment estimations to ground-truth calculations. For both input segmentations, the predictions errors (nRMSE) were below 0.10 and 0.25 for the sagittal and non-sagittal planes, respectively. The continuous inputs led to a slightly decreased accuracy during stance phases (nRMS
COMPARISON OF DISCRETE (0D) AND CONTINUOUS (1D) ANALYSIS OF SIDESTEP CUTTING KINEMATICS AND KINETICS
Get PDFAlthough both discrete (0D) and continuous (1D) analysis are used, the differences in results between both analyses in repeated measures designs are unclear. Therefore, the purpose of this study was to compare the results of a discrete and continuous analysis on the same dataset. Data of an intervention study regarding sidestep cutting with two groups and three sessions of measurements were used. Analyses of mean and peak values (0D) and timeseries (1D) revealed contradictory results for some variables. More interestingly, the direction of the results was different sometimes. This substantiates the impact that an analysis method can have on data interpretation and warrants caution in drawing conclusions. Researchers are encouraged to ensure that their analysis method is appropriate to answer their research question and a priori hypothesis
WHERE AND WHEN: IDENTIFYING KEY REGIONS OF OVERGROUND SPRINT FOR HORIZONTAL FORCE-VELOCITY PROFILING
Get PDFThe purpose of this study was to identify regions of an overground sprint trial required to accurately determine independent Horizontal Force Velocity (FV) measures. Forty-seven university aged athletes completed two separate overground sprint trials. Baseline FV metrics; theoretical maximum velocity [V_0], peak velocity [V_max], maximum power [P_max], maximum theoretical force [F_0], decrease ratio of force [DRF], and force-velocity slope [〖FV〗_slope] were calculated for each trial. Trials were then modified by systematically removing percentages of the total sprint from the beginning and end of the trial independently. FV metrics were compared at each percentage stage and compared to baseline. Results of this analysis indicate that no changes occur in FV variables until 7% of the sprint is removed from the end of the sprint, while significant changes are present after any alteration of data during sprint onset
TWENTY-YEAR TRENDS IN STUDENT READINESS, PERFORMANCE, AND LEARNING IN BIOMECHANICS
Get PDFThe aim of this study was to investigate the trend in student’s Biomechanics Concept Inventory (BCI) performance over the past two decades (2003 - 2023) in the United States. The mean pre-, post-tests of BCI performance, and normalised gain (g) were extracted from published studies for analysis. Eight studies with 937 participants were examined. The Mann-Kendall tests were used to assess the trend of the datasets. No significant downward or upward trends were observed for both pre-tests (p = 1.0) and post-tests (p = 0.07) performance. However, there is an upward trend in students\u27 normalized gains since 2003 (p = 0.02). Over the past twenty years, there has been no significant change in students\u27 BCI entry and exit scores, while mean learning measure g had a large increase as more recent studies have focused on active learning (AL) strategies
POWER UP THE SWING: A BIOMECHANICAL STUDY TOWARDS A GOLF EXOSUIT
Get PDFThis biomechanical study investigates the impact of a passive elastic exoband on golf swing performance, focusing on optimizing the timing and magnitude of its stretch to increase the clubhead velocity. We analyzed the performance of two professional golfers wearing the exoband in four configurations. Our findings suggest that pre-stretching the exoband during the backswing, coupled with an optimal X-factor, significantly increases clubhead velocity by efficiently releasing stored elastic energy. Notably, the configuration pulling the left posterior shoulder towards the left ASIS resulted in the highest clubhead velocity and greatest exoband contribution, demonstrating the importance of optimal stretch and energy transfer for maximizing swing power. This study paves the way for future exosuit designs in golf to harness elastic energy and revolutionize swing mechanics
ASSOCIATION BETWEEN MORPHOLOGY AND HIP AND KNEE JOINT REACTION FORCES DURING RUNNING IN AMERICAN FOOTBALL PLAYERS: IMPLICATIONS FOR OSTEOARTHRITIS DEVELOPMENT
Get PDFNational Football League (NFL) American football players are exposed to osteoarthritis risk factors of obesity and high joint loads. We sought to examine the association between total body mass (TBM), lean body mass (LBM), body fat percent (BFP), peak compressive hip and knee joint reaction forces (JRF), and vertical ground reaction forces (vGRF) in NFL draft eligible players during a high-speed run. One-hundred twenty-five participants ran at 6.5 m/s for 5 sec on an instrumented treadmill. Results showed moderate to low significant negative associations between TBM, LBM, and vGRF and hip and knee compression JRF. There was a negligible significant negative association between BFP and vGRF and hip and knee compression JRF. Players appear to dampen vGRF and JRF. It is unknown if this strategy persists. Findings may be useful in long-term monitoring of player health
ASSISTED TOWING DOES NOT AFFECT ARM STROKE COORDINATION IN FRONT-CRAWL SWIMMING
Get PDFThis study clarified changes in arm stroke coordination during assisted swimming. Fourteen male collegiate swimmers swam 25-m front crawls with (A-swim with towing device) and without an assist (N-swim) at a submaximal to maximum (slow, moderate, and fast) effort. Swimming velocity (v), stroke frequency (SF), stroke length (SL), and stroke coordination index (IdC) were then measured. Results revealed that v and SL exhibited a significant interaction, with higher values observed in the A-swim. Furthermore, v significantly increased with effort, whereas SL showed the opposite. No significant interactions were confirmed for SF and IdC, though SF and IdC significantly increased and decreased, respectively, as the effort increased. In conclusion, despite increased v and SL, A-swim does not affect arm stroke coordination during front crawl swimming
INFLUENCE OF EXTERNAL LOAD AND ECCENTRIC PHASE DURATION ON FORCE PRODUCTION IN THE REAR FOOT-ELEVATED SPLIT SQUAT
Get PDFThe purpose of this case study was to investigate the effects of external load and eccentric phase duration on peak vertical ground reaction force (vGRF) during the rear foot-elevated split squat (RFESS). One resistance-trained male performed RFESS using 40%, 55%, 70% and 85% of 1-repetition maximum loads under two conditions: self-paced versus 2-s eccentric duration. Preliminary results showed that increasing the load from 40% to 85% 1-RM led a mean increase in peak vGRF of 247 ± 76 N. Interestingly, the peak vGRF was always higher in the self-paced condition compared with the 2-s eccentric condition (mean difference = 151 ± 46 N across 4 loads). The case study shows that moderate external loads may achieve similar peak vGRF compared to heavy external loads, and that a fast eccentric phase could be beneficial for increasing peak vGRF in the RFESS