Neil Bezodis

Swansea University | SWAN · Research Centre in Applied Sports, Technology, Exercise and Medicine "A-STEM"

Sprint start performance has previously been quantified using several different measures. This study aimed to identify whether different measures could influence the performance-based ranking within a group of 12 sprinters, and if so, to identify the most appropriate measure. None of the 10 performance measures ranked all sprinters in the same orde...

The start from blocks is a fundamental component of all track and field sprint events (≤ 400 m). This narrative review focusses on biomechanical aspects of the block phase and the subsequent first flight and stance phases. We discuss specific features of technique and how they may be important for a high level of performance during the start. The n...

We aimed to identify differences in kicking leg and torso mechanics between groups of rugby place kickers who achieve different performance outcomes, and to understand why these features are associated with varying levels of success. Thirty-three experienced place kickers performed maximum effort place kicks, whilst three-dimensional kinematic (240...

This study proposed a method to quantify direct and indirect effects of the joint torque inputs in the speed-generating mechanism of a swinging motion. Linear and angular accelerations of all segments within a multi-linked system can be expressed as the sum of contributions from a joint torque term, gravitational force term and motion-dependent ter...

This study aimed to identify the continuous ground reaction force (GRF) features which contribute to higher levels of block phase performance. Twenty-three sprint-trained athletes completed starts from their preferred settings during which GRFs were recorded separately under each block. Continuous features of the magnitude and direction of the resu...

Purpose Post-exercise passive heating has been reported to augment adaptations associated with endurance training. The current study evaluated the effect of a 4-week remotely administered, post-exercise passive leg heating protocol, using an electrically heated layering ensemble, on determinants of endurance performance. Methods Thirty recreationa...

The purpose of this study was to understand how energy is transferred during a rugby place kick and how it differs between successful and less successful kickers. Senior male kickers (n=33) performed maximal range place kicks which were analysed using 3D motion capture (240 Hz), enabling segment powers to be determined. Energy was transferred out o...

Wearable sensors have become increasingly popular for assessing athletic performance, but the optimal methods for processing and analyzing the data remain unclear. This study investigates the efficacy of discrete and continuous feature-extraction methods, separately and in combination, for modeling countermovement jump performance using wearable se...

Wearable sensors have become increasingly popular for assessing athletic performance, but the optimal methods for processing and analysing the data remain unclear. This study investigates the efficacy of discrete and continuous feature extraction methods, separately and in combination, for modelling countermovement jump performance using wearable s...

Purpose: The efficacy of isolated and relative performance indicators (PIs) has been compared in rugby union; the latter more effective at discerning match outcomes. However, this methodology has not been applied in women's rugby. The aim of this study was to identify PIs that maximize prediction accuracy of match outcome, from isolated and relati...

Purpose: This study implemented 18-week individual-specific sprint acceleration training interventions in elite male rugby backs based on their predetermined individual technical needs, and evaluated the effectiveness of these interventions. Methods: Individual-specific interventions were prescribed to five elite rugby backs over an 18-week period....

Purpose: This study implemented 18-week individual-specific sprint acceleration training interventions in elite male rugby backs based on their predetermined individual technical needs and evaluated the effectiveness of these interventions. Methods: Individual-specific interventions were prescribed to 5 elite rugby backs over an 18-week period....

Pressure measurement systems have numerous applications in healthcare and sport. The purpose of this review is to: (a) describe the brief history of the development of pressure sensors for clinical and sport applications, (b) discuss the design requirements for pressure measurement systems for different applications, (c) critique the suitability, r...

Purpose: This study sought to quantify the within-individual relationships between spatiotemporal variables and initial acceleration sprint performance in elite rugby backs and to establish a normative data set of relevant strength-based measures. Methods: First, the spatiotemporal variables, ratios of step length to step rate and of contact time t...

Rowing ergometers are often used by internationally competitive athletes alongside on-water rowing. This study proposes methods to develop a generalisable relationship between maximal effort 2000 m ergometer and on-water rowing performance using independent datasets. Ergometer times for 2000 m tests (n = 153) and 2000 m on-water times from internat...

The purpose of this study was to investigate rugby place kicking technique of elite female players. Five International-level female place kickers took at least five maximum range place kicks, and their technique was analysed using 3D motion capture. In comparison to successful male kickers, females achieved slower kicking foot and ball velocities a...

Lower-limb wearable resistance (WR) facilitates targeted resistance-based training during sports-specific movement tasks. The purpose of this study was to determine the effect of two different WR placements (thigh and shank) on joint kinematics during the acceleration phase of sprint running. Eighteen participants completed maximal effort sprints w...

In track sprinting, acceleration performance is largely determined by the ability to generate a high ratio of forces (RF), but the technical features associated with this remain unknown. This study therefore investigated the relationships between selected kinematic characteristics and RF during the initial acceleration phase. Fourteen male sprinter...

Rugby Union place kicking is influential to match outcome. Previous research has analysed kicker motion prior to ball contact in detail, but ball orientation and the impact phase are typically ignored. This study aims to firstly identify the ball orientations used by international place kickers, and secondly to experimentally analyse the foot-ball...

Few studies have focused on the effect of individual anthropometrics when considering “set” position posture during the sprint start. This study aimed to measure the effect of different anthropometry‐driven block settings on kinetic and kinematic parameters and performance during the start in well‐trained and non‐trained sprinters. Front block‐star...

Objectives The aims of this study were to: i) identify performance indicators (PIs) associated with match outcomes in the United Rugby Championship to; ii) compare efficacy of isolated data and data relative to opposition in predicting match outcome; and iii) investigate whether reduced PI statistical models can reproduce predictive accuracy. Meth...

In complex movements, centre of mass translation is achieved through effective joint and segment rotations. Understanding segment organisation and coordination is therefore paramount to understanding technique. This study sought to comprehensively describe inter- and intra-limb coordination and assess step-to-step changes and between-individual var...

Stretchable, nanocarbon heaters were screen-printed onto a stretchable film to create a passive heat maintenance device for elite sport. The heat uniformity and the temperature performance of these lightweight, large area electrothermal heaters were evaluated over a range of applied voltages using thermal imaging. The heaters provided a uniform hea...

Functional principal components define modes of variation in time series, which represent characteristic movement patterns in biomechanical data. Their usefulness however depends on the prior choices made in data processing. Recent research showed that better curve alignment achieved with registration (dynamic time warping) reduces errors in linear...

This study aimed to identify how body dimensions interact with anteroposterior block distances to influence lower limb joint angles in the “set” position, how these angles relate to block clearance kinetic and kinematic parameters, and how these biomechanical parameters influence sprint start performance in sprinters of both sexes and of different...

External peak power in the countermovement jump is frequently used to monitor athlete training. The gold standard method uses force platforms, but they are unsuitable for field-based testing. However, alternatives based on jump flight time or Newtonian methods applied to inertial sensor data have not been sufficiently accurate for athlete monitorin...

This study developed and evaluated a novel concurrent biofeedback system for the sprint start. Previous studies have investigated sprint start biofeedback applications, but these have either not considered important kinematics, coaching implications or key motor learning principles. The biofeedback system was developed to convey rear knee angle inf...

This study established the magnitude of systematic bias and random error of horizontal force-velocity (F-v) profile variables obtained from a 1080 Sprint compared to that obtained from a Stalker ATS II radar device. Twenty high-school athletes from an American football training group completed a 30 m sprint while the two devices simultaneously meas...

The ability to maintain body temperature has been shown to bring about improvements in sporting performance. However, current solutions are limited with regards to flexibility, heating uniformity and robustness. An innovative screen-printed Nanocarbon heater is demonstrated which is robust to bending, folding, tensile extensions of up to 20% and ma...

Animal-attached devices have transformed our understanding of vertebrate ecology. To minimize any associated harm, researchers have long advocated that tag masses should not exceed 3% of carrier body mass. However, this ignores tag forces resulting from animal movement. Using data from collar-attached accelerometers on 10 diverse free-ranging terre...

Sprint acceleration is an important motor skill in team sports, thus consideration of techniques adopted during the initial steps of acceleration is of interest. Different technique strategies can be adopted due to multiple interacting components, but the reasons for, and performance implications of, these differences are unclear. 29 professional r...

Place kicks present valuable opportunities to score points in Rugby Union, contributing almost half of all points scored at international level. From an ecological dynamics perspective, place kickers adapt to interacting task, environmental, and individual constraints in performance environments. The aim of this study was to analyse effects of spec...

External peak power in the countermovement jump is frequently used to monitor athlete training. The gold standard method uses force platforms, but they are unsuitable for field-based testing. However, alternatives based on jump flight time or Newtonian methods applied to inertial sensor data have not been sufficiently accurate for athlete monitorin...

The aim of this study was to understand how a place kicker’s range is limited by their approach to the ball and their physical characteristics. Thirty-three kickers performed maximal place kicks and vertical jumps in a laboratory. Whole-body motion and ground reaction forces during the approach phase of the kicks, jump performance and anthropometri...

The relationship between the linearity of the ratio of forces (RF)-horizontal velocity (vH) profile and initial acceleration (IA) performance was investigated in trained sprinters. Ground reaction force data from the IA phase of a maximal sprint from a block start were analysed. The coefficient of determination of the linear trendline fitted to fou...

The orientation of the ground reaction force (GRF) vector is a key determinant of human sprint acceleration performance and has been described using ratio of forces (RF) which quantifies the ratio of the antero-posterior component to the resultant GRF. Different methods have previously been used to calculate step-averaged RF, and this study therefo...

Animal-attached devices have transformed our understanding of vertebrate ecology. To minimize tag-related harm for these studies, researchers have long advocated that tag masses should not exceed 3% of the animal’s body mass. However, this proposition ignores tag forces generated as a result of animal movement. Using data from collar-attached accel...

Lower-limb wearable resistance (WR) provides a specific and targeted overload to the musculature involved in sprint running, however, it is unknown if greater impact forces occur with the additional limb mass. This study compared the contact times and ground reaction force waveforms between sprint running with no load and 2% body mass (BM) shank-po...

Time constraints often result in the challenge to fit desired programming into training time allotments. Wearable resistance (WR) may be an option to optimise the training content in function of constrained training time. The purpose of this study was to determine the effects of a lower-limb WR sprint running training intervention on athlete speed...

This study determined the effects of two wearable resistance (WR) placements (i.e. thigh and shank) on horizontal force-velocity and impulse measures during sprint running acceleration. Eleven male athletes performed 50 m sprints either unloaded or with WR of 2% body mass attached to the thigh or shank. In-ground force platforms were used to measur...

This study aimed to: 1) understand how the calculation of step-averaged ratio of forces (RF; horizontal component as a percentage of total ground reaction force (GRF) magnitude) affects the RF-horizontal velocity (vH) profile; 2) establish the importance of RF to early acceleration (i.e. up to the end of step 4) performance; 3) assess how well the...

Animal-attached devices have transformed our understanding of vertebrate ecology. However, to be acceptable, researchers must minimize tag-related harm. The long-standing recommendation that tag masses should not exceed 3% of the animal’s body mass ignores tag forces generated by movement. We used collar-attached accelerometers on four free-ranging...

This study determined the effects of a six-week lower-limb wearable resistance training (WRT) intervention on sprint running time, velocity, and horizontal force-velocity mechanical variables. Twenty-two collegiate/semi-professional rugby athletes completed pre- and post-intervention testing of three maximal effort 30 m sprints. A radar device was...

Place kicks present valuable opportunities to score points in Rugby Union, which are typically performed under varying constraints in competitive performance environments. Previous quantitative studies suggest these interacting constraints can influence fluctuations in place kick success. To further the understanding of how fluctuations in place ki...

The outcomes of place kicks can have a large impact on Rugby Union match results. This study investigated the ball orientations used in place kicking and their potential implications for success. All 416 place kicks from the 2019 Rugby World Cup were grouped into one of three ball orientation categories, and predicted odds of success were calculate...

Successful sprinting depends on covering a specific distance in the shortest time possible. Although external forces are key to sprinting, less consideration is given to the duration of force application, which influences the impulse generated. This study explored relationships between sprint performance measures and external kinetic and kinematic...

Printed pressure sensors have the potential to be useful for measuring pressure in a multitude of sports biomechanics applications. This study was a proof of concept of a novel printed piezoresistive pressure sensor array with the aim of assessing the reliability of the sensor. The relationship between the force applied to the sensor and resistance...

Purpose Whilst kicking in Rugby Union can be influential to match outcome, the epidemiology of kicking injuries remains unknown. This study therefore aimed to investigate the epidemiology of injuries attributed to kicking in professional rugby, including playing position‐specific effects and differences in kicking volumes and kick types. Methods F...

Light wearable resistance is used in sprint training but the scientific evidence to guide its implementation is limited. This study investigated thigh and shank loading protocols which were matched based on the average increase in moment of inertia about the hip over a stride cycle. Seven university-level sprinters completed three counterbalanced c...

Objectives: The primary aim of this paper was to produce a model that predicts outcome in the group-phase of the 2015 Rugby World Cup and to determine the relevance and importance of performance indicators (PIs) that are significant in predicting outcome. A secondary aim investigated whether this model accurately predicted match outcome in the kno...

Anaerobic performance in youth has received little attention partly due to the lack of a “gold-standard” measurement. However, force-velocity-power (F-v-P) profiling recently showed high reliability and validity in trained adults. Therefore, the aim was to determine the reliability of F-v-P profiling in children and adolescents. Seventy-five childr...

In table tennis the follow-through action after a shot is an important part of skill execution. In this experiment, we aimed to extend literature around the contextual interference effect by investigating whether the way the follow-through is organised in practice affects learning of the backhand shot in table tennis. Thirty unskilled participants...

We aimed to evaluate the accuracy of a new method to calculate the centre of pressure (COP) on a starting block above a force platform, and to examine how this method affected lower extremity joint torques during the block clearance phase compared against a previously used method which projects the COP from the metatarsophalangeal (MP) joint. To ev...

Place kicking is a complex whole-body movement that contributes 45% of the points scored in international Rugby Union. This study compared the kicking foot swing plane characteristics of accurate and inaccurate kickers, underpinned by differences in their support leg and pelvis kinematics at support foot contact, to identify key technique character...

Objectives: The primary aim of this study was to examine whether accuracy of rugby union match prediction outcomes differed dependent on the method of data analysis (i.e., isolated vs. descriptively converted or relative data). A secondary aim was to then use the most appropriate method to investigate the performance indicators (PI's) most relevan...

The initial steps of a sprint are important in team sports, such as rugby, where there is an inherent requirement to maximally accelerate over short distances. Current understanding of sprint acceleration technique is primarily based on data from track and field sprinters, although whether this information is transferable to athletes such as rugby...

The aim of this study was to investigate spatiotemporal and kinematic changes between the initial acceleration, transition and maximum velocity phases of a sprint. Sagittal plane kinematics from five experienced sprinters performing 50-m maximal sprints were collected using six HD-video cameras. Following manual digitising, spatiotemporal and kinem...

We examined the effects of anxiety and situation-specific contextual information on attentional, interpretational, and behavioural processes underpinning perceptual–motor performance as proposed by Nieuwenhuys and Oudejans (2012) using an in situ task. Twelve skilled cricket batsmen played against a skilled spin bowler under conditions manipulated...

Place kicks in Rugby Union present valuable opportunities to score points outside the spatiotemporal dynamics of open play but are executed under varying performance constraints. We analysed effects of specific task constraints and relevant contextual factors on place kick performance in the 2015 Rugby Union World Cup. Data were collected from tele...

The appropriate determination of performance outcome is critical when appraising a performer’s technique. Previous studies of rugby place kicking technique have typically assessed performance based on ball velocity, but this is not the sole requirement. Therefore, a mathematical model of rugby place kick ball flight was developed to yield a single...

When performing under severe time constraints, sports performers use kinematic and contextual information to facilitate anticipation. We examined the relative importance of these two information sources and their impact on cognitive load and anticipation performance. Cognitive load theory predicts that adding more information sources to a task will...

There has been a growing tendency in sport science research to examine the relationship between empirical knowledge developed in scientific experiments and theoretical frameworks and the experiential knowledge of elite performers and practitioners (Jones, Bezodis, & Thompson, 2009; Greenwood, Davids, & Renshaw, 2014; Phillips, Davids, Renshaw, & Po...

The aim of this study was to investigate spatiotemporal and kinematic changes between the initial acceleration, transition and maximum velocity phases of a sprint. Sagittal plane kinematics from five experienced sprinters performing 50 m maximal sprints were collected using six HD-video cameras. Following manual digitising, spatiotemporal and kinem...

THE ABILITY TO CHANGE DIRECTION IS A HIGHLY VALUED ATHLETIC QUALITY IN SPORT AND HAS BEEN MEASURED EXTENSIVELY. DESPITE THE IMPORTANCE AND MAGNITUDE OF RESEARCH ON CHANGE OF DIRECTION (COD) AND AGILITY, THE VALIDITY OF THE PERFORMANCE MEASURES USED TO ASSESS THESE ABILITIES HAVE FACED LIMITED SCRUTINY. A CRITICAL EVALUATION OF OUR CURRENT MEASURES...

Place kicks in Rugby Union present opportunities to score points without the spatiotemporal dynamics of open play, but are typically executed under varying task and contextual performance constraints within competitive environments. The average success percentage of place kicks in international Rugby Union (2002 - 2011) was 72%, however, success pe...

The ability to anticipate is essential when performing under severe time constraints. Skilled sports performers use kinematic information from opponents’ movements and sources of contextual information (e.g., score, field positions) to facilitate anticipation. Few researchers have investigated the relative importance of these two information source...