Virtual skeleton methodology for athlete posture modification in CFD simulations
This study focuses on the aerodynamic influence of athlete posture in sports aerodynamics. To analyze a specific posture, wind tunnel measurements and computer simulations are commonly employed. For computer simulations, the growing trend is to use 3D scanning to create accurate representations of an athlete ’s geometry. However, this process becomes cumbersome and time-consuming when multiple positions need to be scanned. This work presents a methodology to use a virtual skeleton to perform modifications of an athlete’s posture. This is an efficient approach that can be applied directly to a scanne d geometry model, a...
Source: Sports Engineering - August 30, 2023 Category: Sports Medicine Source Type: research
Examining differences in kinematics and boat loading patterns in towed water sports
This article presents a sample of pilot testing data for ten participants to show that the methodology can be used to compare water sports activities. Four towed water sports were examined: towed inflatables, slalom skiing, wakeboarding, and barefoot skiing. Participant and boat position and velocity, and tow rope force were evaluated. Each sport was examined in normal operation; slalom skiing was examined as a “free ski”, rather than a slalom course. The largest tow rope force occurred for the 6-person towable inflatable (5443 N). The largest peak tow rope force normalized to total participant body weight occurred dur...
Source: Sports Engineering - August 30, 2023 Category: Sports Medicine Source Type: research
The influence of sub-technique and skiing velocity on air drag in skating style cross-country skiing
AbstractIn cross-country skiing, velocities range from 2 m \({\textrm{s}}^{-1}\) up to more than 20 m \({\textrm{s}}^{-1}\) across undulating terrain, and aerodynamics can, therefore, make a large impact on performance. The aim of this study was to investigate the influence of skiing velocity on air drag for skating sub-techniques and downhill postures (tuck). Dynamic and static drag measurements for two athletes were performed in a wind tunnel in relevant velocity ranges for each sub-technique. The drag area decreased with velocity from 2 m \({\textrm{s}}^{-1}\) to around 10 –12 m \({\textrm{s}}^{-1}\), where...
Source: Sports Engineering - August 7, 2023 Category: Sports Medicine Source Type: research
On technical considerations of velodrome track design
AbstractA novel approach to velodrome track design is presented. The mathematical model uses differential geometry to form a three-dimensional ruled surface. The surface accounts for the safety zone, blue band, and track region, the latter of which is comprised of three segments: straight lines, the arcs of circles, and connecting transition curves. Following a first-principles approach, the general expressions are derived from the Frenet –Serret relations, as a function of the banking and curvature profiles, lengths of curve segments, and turn radius of the bends. Particular solutions to the design problem are obtained ...
Source: Sports Engineering - July 19, 2023 Category: Sports Medicine Source Type: research
Topical Collection on Football Research
(Source: Sports Engineering)
Source: Sports Engineering - July 15, 2023 Category: Sports Medicine Source Type: research
Understanding the variability in rotational traction testing on artificial turf
AbstractRotational traction is a key parameter used by sporting governing bodies to determine the safety and performance of artificial turf surfaces. Currently, the Federation Internationale de Football uses two devices for measuring rotational traction: a statically loaded rotational traction tester and a lightweight rotational traction tester, loaded by the operator. Variability in measurements emanates from two main sources: inconsistencies in the turf and the manual operation of both testers. The purpose of this study was to investigate the contributions from the turf and the manual operation of the testers to the tota...
Source: Sports Engineering - July 7, 2023 Category: Sports Medicine Source Type: research
The effect of surface geometry on the aerodynamic behaviour of a football
This study commissioned many 3D printed footballs with regularly increasing seam length and surface texture to undertake a designed experiment to study these changes in a controlled fashion. Each ball was tested in a wind tunnel in non-spinning cases, or spinning about a vertical axis, at a range of speeds and key aerodynamic parameters were extracted from the data. Several methods were employed to characterise theroughness of each ball, and these roughness metrics were statistically tested for correlations with selected aerodynamic parameters. Using these relationships provides design guidance to football manufacturers to...
Source: Sports Engineering - July 5, 2023 Category: Sports Medicine Source Type: research
Six inertial measurement unit-based components describe wheelchair mobility performance during wheelchair tennis matches
AbstractThe aim of this explorative study was to determine the key inertial measurement unit-based wheelchair mobility performance components during a wheelchair tennis match. A total of 64 wheelchair tennis matches were played by 15 wheelchair tennis players (6 women, 5 men, 4 juniors). All individual tennis wheelchairs were instrumented with inertial measurement units, two on the axes of the wheels and one on the frame. A total of 48 potentially relevant wheelchair tennis outcome variables were initially extracted from the sensor signals, based on previous wheelchair sports research and the input of wheelchair tennis exp...
Source: Sports Engineering - July 1, 2023 Category: Sports Medicine Source Type: research
Validation of a multi-camera videogrammetry approach for quantifying helmet impact velocity in football
This study presents the validation of a multi-camera videogrammetry approach for measuring football helmet impact velocities, wherein the effect of camera angle, camera distance and impact speed were assessed. Helmet-to-ground impacts were simulated within two zones on a field using free fall drop tests of a helmeted head and neck assembly at heights of 1.04 m (slow: 4.52 m/s) and 1.83 m (fast: 5.99 m/s). Helmet motion was manually tracked using 3D motion analysis software for different camera combinations (e.g., orthogonal, coincident, overhead, and parallel camera pairs) in each zone. Maximum errors of the 3D calibr...
Source: Sports Engineering - June 13, 2023 Category: Sports Medicine Source Type: research
Correction of systematic errors in electronic performance and tracking systems
AbstractElectronic performance and tracking systems are becoming a standard in many sports to automate data collection and gather more profound insights into performance and game dynamics. In large soccer clubs and federations, the problem is that different electronic performance and tracking systems report different kinematic parameters and performance indicators, which should be the same. Furthermore, a drawback in recent validation studies is the subdivision of speed and acceleration zones in validating the systems, as we show that the kinematic parameters are interdependent. We propose a new method to classify multidim...
Source: Sports Engineering - June 7, 2023 Category: Sports Medicine Source Type: research
Prediction of disc golf drivers ’ aerodynamic characteristics using Reynolds Averaged Navier Stokes computational fluid dynamics
AbstractPrevious research manuscripts in sports (disc golf, cycling, and motorsports in particular) and the automotive industry have demonstrated the need for improved predictive capabilities of Reynolds Averaged Navier Stokes aerodynamic simulations. This paper presents work performed to improve these capabilities for golf discs. The relatively new Lag elliptic blendingk–ε turbulence model and the well-establishedk–ω Shear Stress Transport model were trialed in golf disc computational fluid dynamics analyses in this study. The predictive capabilities of the Lag elliptic blendingk–ε turbulence model were improved ...
Source: Sports Engineering - May 24, 2023 Category: Sports Medicine Source Type: research
Design-property decision-making in polymer lattices when controlling for printed mass
This study aims to demonstrate the ability of additive manufacturing to enhance the performance of polymer lattices in sporting equipment by establishing a systematic workflow for rapid design-fabrication-performance evaluation. The investigation develops a framework to enable optimal selection of lattice design and performance variables such as printed mass and compressive modulus. The objectives were to: (i) define a comprehensive workflow to evaluate lattices using a polymer laser powder bed process, namely—selective laser sintering, (ii) inve stigate the printability and compression performance of commonly designed...
Source: Sports Engineering - May 21, 2023 Category: Sports Medicine Source Type: research
Validity and reliability of an opto-electric training system in elite and national level ISSF air rifle shooters
AbstractThe validity of a commonly used optoelectronic training system was examined by identifying the variables that predicted shot score, investigating their ability to discriminate standard, and assessing the predictive variables ’ test–retest error. A repeated-measures approach assessed test–retest error, a cross-sectional approach compared standards of shooters and an observational approach examined predictors of shot score. 21 elite and 8 national-standard athletes participated. Multiple linear regression, independe nt t tests, typical error and coefficient of variation assessed predictors of shot score, discri...
Source: Sports Engineering - May 20, 2023 Category: Sports Medicine Source Type: research
Validation of football locomotion categories derived from inertial measurements
AbstractIn sports like football, knowledge concerning physical demands is used for training sessions and matches. Inertial measurement units are often used to estimate physical demands. Catapult Sports has recently developed, based on acceleration and gyroscope data, the Football Movement Profile algorithm that enables to categorize physical demands into locomotion categories facilitating the interpretation of practitioners. The aim of this study was to assess the validity of the locomotion predictions derived from the Football Movement Profile during controlled drills. Data were collected from 41 elite youth football play...
Source: Sports Engineering - May 9, 2023 Category: Sports Medicine Source Type: research
Free-fall drop test with interchangeable surfaces to recreate concussive ice hockey head impacts
AbstractIce hockey has one of the highest concussion rates in sport. During collisions with other players, helmets offer limited protection. Various test protocols exist often requiring various types of laboratory equipment. A simplified test protocol was developed to facilitate testing by more researchers, and modifications to certification standards. Measured kinematics (acceleration vs. time trace shape, peak accelerations, and impact duration) of a Hybrid III headform dropped onto different surfaces were compared to published laboratory representations of concussive impacts. An exemplary comparison of five different he...
Source: Sports Engineering - May 9, 2023 Category: Sports Medicine Source Type: research
