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Stuart McErlain-Naylor

Lecturer in Sport and Exercise Biomechanics

Loughborough University

Biography

Dr Stuart McErlain-Naylor is a Lecturer in Sport and Exercise Biomechanics at Loughborough University, 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.

Interests

  • sporting technique
  • impact accelerations
  • flywheel exercise

Education

  • 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

Badminton

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

The effect of flywheel inertia on peak power and its inter-session reliability during two unilateral hamstring exercises: leg curl and hip extension

This study investigated the effect of flywheel moment of inertia (0.029, 0.061, and 0.089 kg·m2) on concentric and eccentric peak power and eccentric:concentric peak power ratio during unilateral flywheel leg curl and hip extension exercises. Moreover, the inter-session reliability of peak power was analyzed during both exercises. Twenty amateur male soccer athletes attended five visits—performing three sets of eight repetitions of either unilateral leg curl or hip extension (all three moments of inertias) during each visit. For the unilateral leg curl, there were no differences in any measure between moments of inertia (p = 0.479) but a higher eccentric than concentric peak power for all moments of inertia (p < 0.001). For the unilateral hip extension, differences between moments of inertia were reported for all measures (p < 0.05). Specifically, the lowest moment of inertia elicited the greatest concentric peak power (p = 0.022), there were no differences with the medium inertia (p = 0.391), and the greatest moment of inertia obtained the greatest eccentric peak power (p = 0.036). Peak power measures obtained acceptable to excellent reliability while the eccentric:concentric ratio reported unacceptable to good reliability for both exercises. A variety of moments of inertia can elicit high eccentric knee flexor demands during unilateral leg curls, whereas higher moments of inertia are needed to achieve an eccentric-overload in peak power during hip extensions. Different exercises may have different inertia-power relationships. Concentric and eccentric peak power measures should continue to inform training, while the eccentric:concentric ratio should not be used.

Hitting for Six: Cricket Power Hitting Biomechanics

Drs Stuart McErlain-Naylor, Chris Peploe, Paul Felton and Professor Mark King discuss biomechanical principles underpinning maximising power hitting success in cricket.

Problem based learning: a netball / basketball shooting problem for projectile motion

As a sport scientist working in a multi-sport organisation, the national netball or basketball coach approaches you with a question. They currently use defenders during shooting practice but are concerned about the extra demands this is placing on their defenders during a congested competition period. The coach wants to know whether removing the defenders from the practice environment will affect the trajectory of the shots. If so, they wonder if a mannequin defender could be used as a compromise.

Factors influencing the jump momentum – sprint momentum correlation: a data simulation

Jump take-off momentum has previously been proposed as an alternative test to predict sprint momentum. This study used a data simulation to replicate and systematically investigate relationships reported in previous studies between body mass, vertical jump performance, and sprint performance. Results were averaged for 1000 simulated data sets in each condition, and the effects of various parameters on correlations between jump momentum and sprint momentum were determined. The ability of jump take-off momentum to predict sprint momentum is greatest under relatively high inter-individual variation in body mass and relatively low inter-individual variation in jump height. This is largely due to the increased emphasis on body mass in these situations. Even under zero or a small negative (r = -0.30) correlation between jump height and sprint velocity, the correlation between the two momenta remained very large (r ≥ 0.76) on average. There were no investigated conditions under which jump momentum was most frequently a significantly (p < 0.05) greater predictor of sprint momentum compared to simply using body mass alone. Furthermore, between-individual correlations should not be used to make inferences or predictions for within-individual applications (e.g., predicting or evaluating the effects of a longitudinal training intervention). It is recommended that any rationale for calculating and/or monitoring jump take-off momentum should be separate from its ability to predict sprint momentum. Indeed, body mass alone may be a better predictor of sprint momentum.

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.