Stuart McErlain-Naylor

Senior Lecturer in Sport and Exercise Biomechanics

University of Suffolk


Dr Stuart McErlain-Naylor is a Senior Lecturer in Sport and Exercise Biomechanics and Co-Lead of the Sport Performance and Exercise Sciences Research Interest Group at the University of Suffolk, UK. He is currently Vice President (Publications) of the International Society of Biomechanics in Sports.

His research interests include kinetic and kinematic analysis of sporting techniques (mostly ball striking sports), analysis of post-impact accelerations, and the mechanics of flywheel resistance exercise.

Stuart organised and hosted the Sports Biomechanics Lecture Series , and is Social Media Editor for the journal Sports Biomechanics. .

To discuss collaboration or consultancy, just send a mesage. For the best things I read each month, as well as publication, presentation, and project updates, please subscribe to my monthly newsletter.


  • sporting technique
  • impact accelerations
  • flywheel exercise


  • PhD in Sports Biomechanics, 2018

    Loughborough University

  • Postgraduate Certificate in Academic Practice (Fellow of the Higher Education Academy), 2020

    University of Suffolk

  • BSc in Sport and Exercise Sciences, 2013

    Loughborough University

Content and Resources

  • Publications: View and search open access versions of my publications and related resources

  • Lectures: 28 free expert lectures on sports biomechanics, as well as tutorials and research presentations

  • Resources: Recommended free resources for every stage of the research process

  • Newsletter: A monthly update of the best things I’ve read recently, as well as publications and resources

Research Projects

Cricket Batting

The biomechanical determinants of cricket batting performance


The biomechanical determinants of badminton jump smash performance

Flywheel Exercise

Flywheel (isoinertial) eccentric overload exercise induced post-activation performance enhancement

Impact Accelerations

The effect of compliance on post-impact elastic wave accelerations

Most Recent Publications

Perception and application of flywheel training by professional soccer practitioners

Growing evidence supports use of eccentric methods for strength development and injury prevention within elite soccer, yet uncertainty remains regarding practitioners’ application of flywheel (isoinertial) methods. The aims of this study were to investigate how the flywheel training literature is perceived and applied by elite soccer practitioners, highlight gaps in knowledge and develop industry-relevant research questions. Fifty-one practitioners completed an electronic questionnaire. Fourteen Likert scale statements were grouped into topics: strength and performance; post-activation performance enhancement and methodological considerations; chronic strength; chronic performance; injury prevention. Three general questions followed, allowing more detail about flywheel training application. A Majority of the participants reported ≥ 2 years’ experience of programming flywheel training. Nearly all participants agreed that familiarisation is needed. Practitioners agree that flywheel training can improve sport performance, strength and likelihood of non-contact injury outcomes. Most practitioners prescribe 2 weekly sessions during pre- and in-season periods. Flywheel sessions mostly consist of squats but a variety of exercises (lunge, hip hinge, and open kinetic chain) are also frequently included. Practitioners are mostly unsure about differences between flywheel and traditional resistance training equipment and outcomes, practicality of flywheel equipment, and evidence-based guidelines. The investigation provides valuable insight into the perspectives and application of flywheel training within elite soccer, highlighting its perceived efficacy for strength and injury prevention.

Inter-individual Variation in Coordination and Control of Countermovement Jumps

A modified vector coding technique was used to quantify coordination and control during countermovement jumps by 16 males. Previously reported group-level coordination patterns were confirmed, although substantial inter-individual variation existed. Patterns of thigh-shank coordination and control were observed corresponding to a ‘deep’ or ‘shallow’ countermovement strategy, each used successfully within the cohort.

Comparing power hitting kinematics between skilled male and female cricket batters

Organismic, task, and environmental constraints are known to differ between skilled male and female cricket batters during power hitting tasks. Despite these influences, the techniques used in such tasks have only been investigated in male cricket batters. This study compared power hitting kinematics between 15 male and 15 female batters ranging from university to international standard. General linear models were used to assess the effect of gender on kinematic parameters describing technique, with height and body mass as covariates. Male batters generated greater maximum bat speeds, ball launch speeds, and ball carry distances than female batters on average. Male batters had greater pelvis-thorax separation in the transverse plane at the commencement of the downswing (β = 1.14; p = 0.030) and extended their lead elbows more during the downswing (β = 1.28; p = 0.008) compared to female batters. The hypothesised effect of gender on the magnitude of wrist uncocking during the downswing was not observed (β = −0.14; p = 0.819). The causes of these differences are likely to be multi-factorial, involving aspects relating to the individual players, their history of training experiences and coaching practices, and the task of power hitting in male or female cricket.

A Review of Forward-Dynamics Simulation Models for Predicting Optimal Technique in Maximal Effort Sporting Movements

The identification of optimum technique for maximal effort sporting tasks is one of the greatest challenges within sports biomechanics. A theoretical approach using forward-dynamics simulation allows individual parameters to be systematically perturbed independently of potentially confounding variables. Each study typically follows a four-stage process of model construction, parameter determination, model evaluation, and model optimization. This review critically evaluates forward-dynamics simulation models of maximal effort sporting movements using a dynamical systems theory framework. Organismic, environmental, and task constraints applied within such models are critically evaluated, and recommendations are made regarding future directions and best practices. The incorporation of self-organizational processes representing movement variability and “intrinsic dynamics” remains limited. In the future, forward-dynamics simulation models predicting individual-specific optimal techniques of sporting movements may be used as indicative rather than prescriptive tools within a coaching framework to aid applied practice and understanding, although researchers and practitioners should continue to consider concerns resulting from dynamical systems theory regarding the complexity of models and particularly regarding self-organization processes.

Inter-unit reliability of IMU Step metrics using IMeasureU Blue Trident inertial measurement units for running-based team sport tasks

The aim of this study was to determine the inter-unit reliability of IMU Step biomechanical load monitoring metrics using IMeasureU Blue Trident inertial measurement units in tasks common to running-based team sports. Knowledge of variability between units is required before researchers and practitioners can make informed decisions on “true” differences between limbs. Sixteen male college soccer players performed five running-based tasks, generating 224 trials and 17,012 steps. Data were analysed for each task and for the whole session, investigating six IMU Step metrics: step count; impact load; bone stimulus; and low, medium and high intensity steps. Inter-unit reliability was excellent (ICC ≥ 0.90) for 21 out of 26 metrics, and good (0.83 ≤ ICC ≤ 0.86) for all other metrics except for Yo-Yo impact load (ICC = 0.79) which was acceptable. These findings confirm the inter-unit reliability of IMU Step metrics using IMeasureU Blue Trident inertial measurement units for running-based team sports. Now that inter-unit variability has been quantified, researchers and practitioners can use this information when interpreting inter-limb differences for monitoring external biomechanical training load.