Biomechanical load quantification of national and regional soccer players with an inertial sensor setup during a jump, kick, and sprint task: assessment of discriminative validity
AbstractTraining load quantification methods may help optimize soccer performance. However, whole-body indicators potentially underestimate biomechanical load. A new inertial sensor setup allows joint-specific biomechanical load quantification. Good discriminative validity further supports the use of this method, and therefore the purpose of this study is to assess the discriminative validity of this method during soccer-specific activities. Twelve national and sixteen regional soccer players wore an inertial sensor setup and performed countermovement jumps, soccer kicks, and 30 m sprints. Between-group differences in an...
Source: Sports Engineering - April 19, 2024 Category: Sports Medicine Source Type: research
Three-dimensional golf clubhead-ball impact models for drivers and irons
AbstractImpact models are an important tool for golf equipment design as they allow for computer simulations to evaluate and optimize performance. There are several published driver impact models for this purpose. However, existing impact models have no or limited experimental validation to support their conclusions. The aim of this research was to extend several impact models from the literature to predict three-dimensional driver impacts and, for the first time, iron impacts. The accuracy of these models was evaluated using experimental data. Two impulse-momentum and three continuous contact models were applied to create...
Source: Sports Engineering - April 17, 2024 Category: Sports Medicine Source Type: research
The reliability and validity of the Affinity Altitude hypoxic generators in acute and chronic conditions
This study investigated the reliability of the Affinity Altitude hypoxic generator within-day, between-day and between-generator under acute and chronic hypoxic conditions. An additional objective was to assess the validity of the fraction of inspired oxygen (FiO2) values in relation to the claimed manufacture ’s reference values to ensure the accuracy and safety of the product. Three altitude generators (Affinity Altitude Ltd., Sussex, UK) were assessed across all available settings during a test–retest design for equivalent FiO2 and output volume. This consisted of two phases: 1) acute exposure (10 min per setting)...
Source: Sports Engineering - April 13, 2024 Category: Sports Medicine Source Type: research
The video assistant referee in football
AbstractThe video assistant referee (VAR), popularized in football (soccer), has been decisive in many games played in several international and domestic competitions ever since the F édération Internationale de Football Association (FIFA) formalized its use for the first time in the 2018 Men’s Football World Cup. Serving as a support tool for on-field referees, it is not only a game unifier but also a conflict pacifier by using a technology-based method to objectively apprec iate whether human decisions were accurate and fair or erroneous and thus in need of correction. Given the overwhelming support evidenced by its ...
Source: Sports Engineering - April 12, 2024 Category: Sports Medicine Source Type: research
Influence of infill depth and fibre height of artificial turf on rotational traction
This study aimed to determine the influence of infill depth and the exposed fibre height on shoe –surface traction for artificial turf surfaces. Particular focus was placed upon rotational traction, which has been associated with lower extremity injuries in sports. Ten artificial turf surfaces with varying infill depth and exposed fibre length were mechanically tested, with results indicating a significant impact of infill depth on rotational traction (F = 3.150,p = 0.017,\({\eta }^{2}\) = 0.104); as infill depth increased, a reduction in rotational traction was observed. For surfaces with longer carpet fibres, a...
Source: Sports Engineering - April 5, 2024 Category: Sports Medicine Source Type: research
Loading and structural stiffness of tandem bicycle frames
AbstractTandem bicycles are used for all para-cycling events for visually impaired athletes. Tandems are structurally more challenging to design than solo bicycles: they must resist higher loading over a longer wheelbase, yet must still fit between the legs of the riders. Despite this, there is limited published work on tandem design. This paper presents a method for determining maximal loading of a tandem bicycle frame in racing scenarios. The only inputs required are the dimensions of the frame and the torques exerted by the riders. Outputs are the forces acting on the frame. The method is used to provide loads for struc...
Source: Sports Engineering - March 28, 2024 Category: Sports Medicine Source Type: research
Running work capacity over critical power: a variable rather than a constant parameter
AbstractThe work capacity over critical power is theoretically defined by the curvature constant. However, this parameter has been characterized by a large standard error of the estimate. Therefore, this study aims to determine the validity of this parameter to represent the work performed over critical power on different time trials along the severe intensity domain. Athletes performed four-time trials (3, 5, 10 and 20 min) in a two-week training period on a 400-meter outdoor track. The mean power output of each time trial was measured through the Stryd power meter, and the inverse of the time model was used. The work dep...
Source: Sports Engineering - March 27, 2024 Category: Sports Medicine Source Type: research
Running critical power: between-day, interlimb and interunit reliability
In conclusion, practitioners should consider these values when using the commercial power meter to interpret meaningful changes in performance and asymmetries between lower limbs. (Source: Sports Engineering)
Source: Sports Engineering - March 15, 2024 Category: Sports Medicine Source Type: research
Modelling of a cyclist ’s power for time trials on a velodrome
AbstractWe formulate a phenomenological model to study the power applied by a cyclist on a velodrome —for individual timetrials—taking into account the straights, circular arcs, connecting transition curves, and banking. The dissipative forces we consider are air resistance, rolling resistance, lateral friction and drivetrain resistance. Also, in general, the power is used to increase the kinet ic and potential energy. However, to model a steady ride—as expected for individual timetrials—we assume a constant centre-of-mass speed and allow the cadence and power to vary during a lap. Hence, the only mechanical energy...
Source: Sports Engineering - March 4, 2024 Category: Sports Medicine Source Type: research
Maximizing ollie height by optimizing control strategy and skateboard geometry using direct collocation
AbstractThe ollie is the base aerial human –board maneuver, foundational to most modern skateboarding tricks. We formulate and solve an optimal control problem of a two-dimensional simplified human model and a rigid body skateboard with the objective of maximizing the height of the ollie. Our solution simultaneously discovers realistic hum an-applied force trajectories and optimal board geometry. We accomplish this with a direct collocation formulation using a null seed initial guess by carefully modeling the discontinuous aspects of board–ground impact and foot–board friction. This leads to efficient and robust solu...
Source: Sports Engineering - February 29, 2024 Category: Sports Medicine Source Type: research
Accuracy and reproducibility of a novel device for monitoring resistance training performed at self-selected movement velocity
This study evaluated the accuracy and precision of a linear encoder in estimating the maximum number of repetitions during sets performed until failure at self-selected movement velocity. Fifty-seven males were evaluated in three resistance exercises: close-grip lat pulldown, knee extension, and bench press. A ccuracy was evaluated by comparing the mean and median of actual and estimated repetitions usingt tests and Wilcoxon signed-rank tests, respectively. Additionally, the fatigue effect in consecutive sets was analyzed using two-way ANOVA for repeated measures. Levels of agreement were assessed through Bland –Altman a...
Source: Sports Engineering - February 21, 2024 Category: Sports Medicine Source Type: research
Apparatus and methodology for smart trainer homologation analysis
AbstractVirtual cycling engagement has seen a significant increase in the last decade, with a recognizable surge in 2020 due to the pandemic. To ensure a fair competition field, a testing apparatus was designed to test direct-drive bicycle smart trainers from various manufacturers. Smart trainers were tested for error on two main metrics: power measurement error and resistance error. Given that the integrity of virtual racing relies upon accurate power readings sent from the smart trainer to a cloud-based competition software, discrepancies in these metrics are most likely to affect the outcome of an event. The testing app...
Source: Sports Engineering - February 2, 2024 Category: Sports Medicine Source Type: research
Correlation of starting order to final time for bobsled competition at the 2022 Olympic games
AbstractIn the sport of bobsledding, only one bobsled is on the track at any given time, and the start order for heats two, three, and four is based on the current standings of the competition. However, for the first heat, the highly ranked competitors can select their starting position from available slots. Making the right decision on the starting order can influence the competition ’s final results. The analysis presented in this manuscript provides scientific backing to the choices being made. This manuscript’s primary focus is analyzing the start order’s impact on the final times for the heats. Olympic bobsleddi...
Source: Sports Engineering - January 31, 2024 Category: Sports Medicine Source Type: research
Individual aerodynamic and physiological data are critical to optimise cycling time trial performance: one size does not fit all
AbstractCycling time trials are characterised by riders adopting positions to lessen the impact of aerodynamic drag. Aerodynamic positions likely impact the power a rider is able to produce due to changes in oxygen consumption, blood flow, muscle activation and economy. Therefore, the gain from optimising aerodynamics must outweigh the potential physiological cost. The aim was to establish the relationship between energy expenditure and aerodynamic drag, with a secondary aim to determine the reliability of a commercially available handlebar mounted aero device for measuring aerodynamic drag. Nine trained male cyclists volu...
Source: Sports Engineering - January 30, 2024 Category: Sports Medicine Source Type: research
Estimating vertical ground reaction forces from plantar pressure using interpretable high-dimensional approximation
AbstractSeveral studies have reported methods for capturing ground reaction forces in the field. However, these forces are usually measured indirectly with non-interpretable “black box” models. Here we report an interpretable model with a function approximation algorithm. The model uses time series of plantar pressure from instrumented insoles to estimate vertical ground reaction forces. The study included data from 16 persons moving at different speeds on a two-bel t treadmill equipped with force plates. The introduced regression model, based on a high-dimensional approximation, using only low-dimensional variable int...
Source: Sports Engineering - January 11, 2024 Category: Sports Medicine Source Type: research
