![Stuart McErlain-Naylor](/img/default-banner.jpg)
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Stuart McErlain-Naylor
United Kingdom
Registrace 21. 03. 2020
Lectures, tutorials, and presentations on SPORTS BIOMECHANICS, research methods, and academia.
Including the Sports Biomechanics Lecture Series #SportsBiomLS - a series of expert guest lectures on topics relating to the biomechanics of various sports and biomechanical data collection and analysis.
Also including the #ScienceofCricket Lecture Series
Please subscribe to keep updated, and follow @biomechstu on Twitter.
For more information, content, and resources: stuartmcnaylor.com
Including the Sports Biomechanics Lecture Series #SportsBiomLS - a series of expert guest lectures on topics relating to the biomechanics of various sports and biomechanical data collection and analysis.
Also including the #ScienceofCricket Lecture Series
Please subscribe to keep updated, and follow @biomechstu on Twitter.
For more information, content, and resources: stuartmcnaylor.com
Training Load Monitoring: The PRACTITIONER'S Perspective (2-part series)
This video is part of a two-part training load collaboration between Stuart McErlain-Naylor (@biomechstu) and Jo Clubb (@globalperformanceinsights) In this series, we wanted to discuss athlete training load monitoring from our two different perspectives; the academic's perspective and the practitioner's perspective. In this video, Jo describes her views from the applied side of training load monitoring.
Check out the other video, with Stuart talking about his perspectives on training load monitoring as a biomechanics researcher, on Jo's channel: czcams.com/video/jlr2XhxmbTg/video.html
CHAPTERS
00:00 Two perspectives on training load monitoring
02:30 How is training load monitored?
06:07 Precision-practicality trade-off in training load monitoring
10:03 How accurate is accurate enough for training load monitoring?
13:49 What do practitioners want to know?
18:02 What questions can training load monitoring answer?
SUBSCRIBE
Stuart's Channel: czcams.com/users/StuartMcErlainNaylor1
Jo's Channel: @globalperformanceinsights
CONNECT
Stuart's Website: www.stuartmcnaylor.com/
Jo's Website: www.globalperformanceinsights...
Twitter: biomechstu
Monthly research newsletter: www.stuartmcnaylor.com/newsletter/
Check out the other video, with Stuart talking about his perspectives on training load monitoring as a biomechanics researcher, on Jo's channel: czcams.com/video/jlr2XhxmbTg/video.html
CHAPTERS
00:00 Two perspectives on training load monitoring
02:30 How is training load monitored?
06:07 Precision-practicality trade-off in training load monitoring
10:03 How accurate is accurate enough for training load monitoring?
13:49 What do practitioners want to know?
18:02 What questions can training load monitoring answer?
SUBSCRIBE
Stuart's Channel: czcams.com/users/StuartMcErlainNaylor1
Jo's Channel: @globalperformanceinsights
CONNECT
Stuart's Website: www.stuartmcnaylor.com/
Jo's Website: www.globalperformanceinsights...
Twitter: biomechstu
Monthly research newsletter: www.stuartmcnaylor.com/newsletter/
zhlédnutí: 865
Video
MOTION CAPTURE: Past, Present, Future of Pose Estimation | Dr Scott Selbie
zhlédnutí 7KPřed 2 lety
30 Years of Motion Capture and Pose Estimation. Dr Scott Selbie, CEO of Theia Markerless and Director of Research at C-Motion, presents “My Life with Pose Estimation”. Scott Selbie discusses the past, present, and future of pose estimation, including comparisons of marker-based and markerless motion capture systems and approaches. Scott discusses the evaluation and validation of various approac...
YouTube for Academia - INTERVIEW | Science in the Break
zhlédnutí 234Před 2 lety
How to start an academic CZcams channel in 2022 - what should you post? How can you include CZcams and video creation in your schedule alongside research and teaching? How can you use CZcams to promote your research and publications, and work alongside journals and conferences? This video is part of an interview by Science in the Break, in which we discuss these topics at length: czcams.com/vid...
I Got My Dream Job at LOUGHBOROUGH UNIVERSITY
zhlédnutí 2KPřed 2 lety
A bit of a life update this week! I’ve got a new job as a Lecturer at Loughborough University. This is just a short vlog update to look forward to the future and say a HUGE thank you to all of the amazing colleagues and students at the University of Suffolk. Subscribe for more videos: czcams.com/users/StuartMcErlainNaylor1 Web: www.stuartmcnaylor.com Twitter: biomechstu Monthly news...
Social Media for Academia - All You Need to Know
zhlédnutí 1,2KPřed 2 lety
Tips, tricks, and strategies to use social media effectively for academia. How should you set up your account? Who should you follow? What should you post? And how can you maximise the reach and impact of your posts? This video will discuss each of these questions and more, focusing mainly on Twitter for academia, but with specific transferrable application to other social media platforms such ...
BioWare: How to Analyse Force Plate Data
zhlédnutí 6KPřed 2 lety
How to analyse ground reaction force data from a force plate within Kistler Bioware software, as well as how to export force platform ground reaction force results or raw GRF data to Excel. This includes how to extract minimum or peak force values, the time of peak force values, impulse, rate of force development, averege force or standard deviation of force in any of the vertical, anterior-pos...
Learn New Skills for Academia
zhlédnutí 414Před 2 lety
Principles and examples for upskilling in academia. These are the principles I use to continually learn new skills for my academic career, including how to code, data visualization, qualitative and quantitative analyses, and more. If you have any of your own principles, let me know in the comments. Subscribe for more videos: czcams.com/users/StuartMcErlainNaylor1 Tutorial videos: Apply sample s...
Biomechanics at the WINTER OLYMPICS | The Future
zhlédnutí 679Před 2 lety
What do researchers think we’ll learn before the next Winter Olympics? We asked winter sports biomechanists in snowboarding, ice hockey, ski jumping, figure skating, speed skating, para sport, and freestyle skiing #WinterOlympicsBiomechanics #Beijing2022 #WinterOlympics Check out the other videos in this Winter Olympics series: czcams.com/play/PLI7VLEjUJidAdu6_tXVMXvdqYhJHZzUWg.html Subscribe t...
Biomechanics at the WINTER OLYMPICS | Part 1
zhlédnutí 1,5KPřed 2 lety
What have researchers learned since the last Winter Olympics? We asked winter sports biomechanists in snowboarding, ice hockey, ski jumping, figure skating, speed skating, para sport, and freestyle skiing #WinterOlympicsBiomechanics #Beijing2022 #WinterOlympics Check out the other videos in this Winter Olympics series: czcams.com/play/PLI7VLEjUJidAdu6_tXVMXvdqYhJHZzUWg.html Subscribe to our cha...
Anticipation & Perceptual Motor Skill in Cricket | Dr Oliver Runswick
zhlédnutí 2,9KPřed 2 lety
Lecture 7 of the #ScienceOfCricket series. Dr Oliver Runswick discusses the role of anticipation and perception in successful cricket batting. What should a batter look at? What information do they use to inform shot selection? How should this be coached? And what can a cricket bowler do to influence this? These questions and many more are answered within the lecture, in reference to many studi...
How to Remember TYPE 1 and TYPE 2 Errors
zhlédnutí 31KPřed 2 lety
A fun and easy way to remember the difference between type 1 errors and type 2 errors. This short story will help you remember and distinguish between false positives and false negatives. So you never have to google type I error or type II error again. Thank you for watching the story of the boy who cried wolf / the boy who cried type 1 error. Check out the related statistics teaching videos be...
Trunk Muscles for Cricket Fast Bowling? │ Prof Benita Olivier
zhlédnutí 4,1KPřed 2 lety
Lecture 6 of the #ScienceOfCricket series. Professor Benita Olivier discusses asymmetry of internal oblique muscle thickness in relation to cricket fast bowling speed and accuracy. She presents an overview of research in this area, including discussion of the trade-off between performance and injury risk factors in cricket fast bowling. See the rest of the Science of Cricket lecture series here...
Cricket Fast Bowling and the Lumbar Spine | Dr Pete Alway
zhlédnutí 6KPřed 2 lety
Lecture 5 of the #ScienceOfCricket series. Dr Pete Alway discusses lumbar spine bone adaptation and risk factors to lumbar bone stress injury in elite cricket fast bowlers. Topics include how the lumbar spine responds to cricket fast bowling, the technique factors driving this adaptation, the permanency of adaptations, epidemiology of lumbar bone stress injuries, and biomechanical technique fac...
The Sweet Spot in Racket or Bat Sports
zhlédnutí 2,4KPřed 2 lety
Understanding the effects of impact location (sweet spot) in racket or bat sports. What does research say about the badminton smash, cricket power hitting, and historical racket development in tennis? This video presents an overview of the scientific research (including my own) on the relationships between impact location and performance outcomes (speed, direction, and margin for error) or inju...
Skill Acquisition in Cricket | Alex Lascu
zhlédnutí 1,6KPřed 2 lety
Lecture 4 of the #ScienceOfCricket series. Alex Lascu discusses how skill acquisition theories can be applied to cricket coaching. This includes ecological dynamics, nonlinear development, task design basics, and environmental constraints. Alex includes practical skill acquisition examples throughout. View the rest of the Science of Cricket lecture series here: czcams.com/play/PLI7VLEjUJidBb-_J...
Cricket Coaching: An Ecological Approach | Dr Rob Gray
zhlédnutí 2,6KPřed 2 lety
Cricket Coaching: An Ecological Approach | Dr Rob Gray
How Muscles REALLY Work: Sliding Filament Theory
zhlédnutí 2,5KPřed 2 lety
How Muscles REALLY Work: Sliding Filament Theory
Gait Cycle Phases, Events and Normalization
zhlédnutí 3,5KPřed 2 lety
Gait Cycle Phases, Events and Normalization
Countermovement Jump Coordination and Control
zhlédnutí 1,4KPřed 2 lety
Countermovement Jump Coordination and Control
Statistical Parametric Mapping (SPM): ANOVA & Others
zhlédnutí 7KPřed 3 lety
Statistical Parametric Mapping (SPM): ANOVA & Others
Cricket Batting Biomechanics Study: Male and Female Power Hitting
zhlédnutí 3,4KPřed 3 lety
Cricket Batting Biomechanics Study: Male and Female Power Hitting
Mendeley Tutorial: Reference Manager - 5 Min Demo
zhlédnutí 69KPřed 3 lety
Mendeley Tutorial: Reference Manager - 5 Min Demo
G*Power Sample Size Calculations: 5 Min Demo
zhlédnutí 179KPřed 3 lety
G*Power Sample Size Calculations: 5 Min Demo
Statistical Parametric Mapping (SPM): Add Labels
zhlédnutí 2,5KPřed 3 lety
Statistical Parametric Mapping (SPM): Add Labels
Statistical Parametric Mapping (SPM): Edit Figures
zhlédnutí 3,1KPřed 3 lety
Statistical Parametric Mapping (SPM): Edit Figures
Statistical Parametric Mapping (SPM) in 6 min
zhlédnutí 19KPřed 3 lety
Statistical Parametric Mapping (SPM) in 6 min
I'm sorry, I'm suffering cause I'm struggling with stadistics, I don't like investigation but I'm working on my thesis, could you help me please? I need to compare three groups, how the hell I do that?
Wow this is stellar work. I have always wanted to know the science and body knowledge behind power hits. If only I knew and came across this years ago. I would have practiced with such knowledge in mind.
In computer science, we used to refer to "pose estimation" as "articulated object tracking," where "pose estimation" referred to the problem of determining the camera pose and the object pose in 3D space. However, the term has become ubiquitous and is now commonly used to mean the posture of a human being in an image or video.
this is point of view from H1. Type 1 being we accept H1 even though it is not true. Type 2 on the other hand is rejecting H1 even though H1 is true.
can you say book for cricket biomechanics
Hi. I'm currently involved in editing a biomechanics book that will have a chapter on cricket, which will be available as a standalone document as well. Not published yet, though.
15:13 can’t wrap my head around this. Is the line coming perpendicular to both thorax and pelvis?. For practical purposes, how is this angle created? By moving your hips and shoulders in opposite direction?. For example, if a batter before ball is delivered stands in a way that his hips are somewhat horizontal (ie in the direction of the cricket stumps, while his shoulders are in one line facing the bowler, ie side on. This would result a slight twist in back but is this what you are referring to the X factor?” Theoretically, would changing the batting stance in a way that hips are facing the leg side boundary and shoulders facing the bowler before ball is delivered generate more power?. Thank you for the informative content you produce.
Hello Stuart. How about a 3 groups non directional test. We have 25 participants in each group, total of 75 and we would like to run the power analysis. Thanks.
I am Physio from Pakistan Cricket Board, I agree with the difference of IO muscle thickness in fast bowler and also in spinner who have more rotatory component in their action. This difference is obvious in all active bowlers and might diminish in non active bowlers, this difference is perhaps due to inactivity of injured bowler during injury, not a primary cause of that injury.
Bless your soul!!! Simple, easy to understand, and to the point! Thank you so much!
Thank you! I really appreciate that.
So glad my professor Peter Lamb recommended this series for a stats primer/reminder. Very informative!
Could you please tell estimated sample size assuming allele frequency 0.1 (10%), additive model, effect size is 2, and disease prevalence 7% with 0.05 % signig=ficance level
It looks like you have an effect size and an alpha level in mind. Just need a desired power and the statistical test that you plan to use. Then the approach in the video can be followed, if that is the desired approach for justifying sample size. Alternatively, if not a standard test then it may require simulation of data sets in R or similar, rather than G*Power
Thanks for creating this
Does the population matter? Where do you input the population?
I'm not sure exactly what you mean, but this approach is purely for a sample size justification based on statistical power, not based on any alternative approach around generalisability or representative sampling, etc.
What type of DEMO software is used for explanation??
Hi. I'm not sure if any specific software was used for simulations or if bespoke code in python, etc. I believe I asked about this a long time ago but can't remember the answer. You'd be better off contacting Todd if you want a correct answer to that. Best wishes
@@biomechstu Thank you for your response. Apart from this, is this valid for only two groups of data?
The SPM approach (and others) can be used for other types of statistical model. For example, you can do an SPM ANOVA with multiple groups/conditions. I have some short tutorials here: czcams.com/play/PLI7VLEjUJidBBtyWFcZYF7f8t8IgMT9cg.html
@@biomechstu Thank you Stuart
How can I get a small portion of respondents from a specific amount of population? I have 351 for total population. I just want to get a portion of that population. How do I do that?
Hi. What statistical test would this be for? If your sample size justification is based onstatistical power, then out could follow the steps in the video. If the justification is based on generalisability or something else then it may be separate
@@biomechstu I'll be using it to get a small percentage of a total population for research
If it's just for a statistical justification based on alpha, effect size, and statistical power, then you can follow the steps regardless of total population. If it is for some other reason then this may not be the required software/approach
Hi Stuart, this is really helpful. Hopefully you still read comments on here as I have a question please! Is it possible to obtain the specific percentages that the significant differences occur at? For example, for the four shaded areas these would seen to occur at ~0-30%, 35-65%, 75-85% and 95-100%. However, I was wondering if these can be calculated (perhaps with confidence interval too) and reported from MATLAB? Best, Ben
Hi Ben. Thanks for the comment. You can definitely export the percentages - i.e., you can print out or export the test statistic used to create the plots and can see where it exceeds the critical test statistic. Or you can output only where it exceeds the threshold. This just needs an extra line or two of code adding. They would be single values. Effect sizes (and confidence intervals around those effect sizes) are tricky for a number of reasons. You can consider the mean difference or maximum difference, etc. as effect sizes if reported appropriately. The forum mentions CIs: spm1d.org/NewFeatures.html#label-confidenceintervals but I would recommend asking Todd / on the forum if interested as I'm not confident to give a correct answer!
Do big strong muscles contribute to six hitting? Sir please reply
I would argue that technique is more important than strength alone, but yes the same 'technique' performed with greater force-production capabilities is likely to result in grdater bat speed and so grdater ball carry distance if it can be timed effectively.
@@biomechstu sir one last question..do strong muscles help in achieving quicker bat speed? And if 2 persons have same bat speed and technique but different body strength will it effect six distance anyways?
If technique, timing, etc. are appropriate then strength is likely to positively effect bat speed. But if bat speed is the same then strength wouldn't effect the ball outcome, as strength can only have an influence through the bat
@@biomechstu players like gayle Russell pollard manage to clear the ropes even when they Miss time the ball sometimes what is the behind that?
Ball distance is a result of bat speed, bat angle, and bat-ball impact location (e.g. sweet spot). Better values for one (e.g., bat speed due to strength) can compensate for suboptimal values in the others as long as the others still remain acceptable and not completely the wrong bat angle or missing the ball, etc.
useful an well presented...would like the steps been drop at the comment section
Great stuff ! Maximum thanks
Amazing lecture! Thank you so much.
Skeleton helmet 🧿🛸 you and tuks need helmet 🪖
Thank you so much for the video.
is this applicable for mediation analysis?
How to straighten a curvy base, please? I have a green and a red electrode I place on the patient along with a concentric needle
really nice but would be even better with explanation and meaning of alternative hypothesis
Amazing knowledge thank you
This pseudo science for dumbies.
Hi, can you show how to calculate a sample size for an epidemiological study? Thank you!
Hi Mario. Unless I've misunderstood, you're fine to follow the same guidance. i.e. figure out what statistical test is required, what your smallest effect size of interest is, your required alpha anf statistical power, and then follow the same steps. How you decide upon each of those parameters for the specific study is obviously the tricky part. Likewise, you may go for a completely different statistical and/or sample size justification approach.
Thank you for your simplified explanation
Thanks for the video. Excellent work.
Hi Stuart, is there any way to save an online backup of all files added to Mendeley References? Thus, not on the laptop itself/desktop.
I'm not sure, sorry. I don't use mine for file storage, so I'm not sure how that aspect works. Although it does seem that greater storage is offered with the Premium plan: www.mendeley.com/reference-management/premium
Wow, as an aerialist this was super interesting and insightful. Have to say Gareth is a great speaker, calm and really engaging. Look forward to more.
but if the sample is small (you have 11 subjects and i have 8), shouldn't we use a non parametric test like Wilcoxon?
There is usually very little difference in results, but this paper provides more detail: doi.org/10.1016/j.jbiomech.2015.02.051
@@biomechstu thank you!
Hi, This video was quite interesting, but may I know the angle you are mentioning is at what reference point w.r.t which plane ?
Hi. Which angle are you talking about? As there were a lot of angles mentioned within the video.
The Optimum launch angle says only the ball angle w.r.t its own plane (above the ground),not the bat angle ? When bat angle is said how we measure that? If it is a straight bat hit
The bat angle is also measured relative to the pitch. In that specific case, we would have been looking at the angle of the bat face about the global medio-lateral axis (i.e. bat pointing down at the ground, pointing back behind, pointing forwards, or what angle in-between) so that this could then be related to the launch angle you mention. Full details of all methods are in the published journal articles, all of which should be free to access in some format. I believe there are links somewhere in the video description.
Send me your email address
Nice
Type I error = Illusion (you are seeing an effect when there is not one) Type 2 error = 2 blind 2 see (you are failing to see an effect when there is one)
couldn't get a poorer quality than that? appreciate the content though
Yeah, unfortunately a product of a poor WiFi connection during a live stream during COVID lockdown. Paul Felton's bowling lecture was streamed on the same day and has the same issue. Let me know if anything unclear as I have the original slides still.
excellent Tutorial. Would look forward for more reference manager tutorials
Simply Brilliant. Thanks a lot
Thanks for the brilliant research and presentation. It was enlightening.
Thanks a lot for sharing the cool work.
Hi I could use your help determining a sample size for a research study
What statistical test do you plan to use in your study? Once you know that, you just need to choose a desired alpha (e.g. 0.05), power (e.g. 80%), and minimum effect size of interest.
Bravo, Johannes!
How do I calculate the sample size for a four arm RCT.
Hi Caroline. Do you know what statistical test you plan to use within your analysis?
Seems like you erroneously state that the effect size box is for inputting the desired effect size but it is actually where you input the effect size you think your intervention or between-condition effect may be. This is why the sample size actually decrease when you increased the value in the effect size box. This is obviously a pretty important issue and the video should be edited to correct the issue.
Hi. This is the effect size you are powering your study to be able to detect if it exists. In some cases, this may be the exact size of effect that you expect but in most cases it won't be. It is often the smallest effect size that would be considered clinically or practically meaningful. For example, I may want to power the study adequately to detect effects of 0.2 or greater if they exist (for some a priori stated reason). This is regardless of what I actually think the effect size might be. As another example, if I anticipate an effect of 0.5 and set up the study to have 80% power to detect an effect size of 0.5 or greater, then my study would be underpowered to detect effects of 0.40 or 0.45, even if these effects are still large enough to be of clinical or practical significance. There are many ways of choosing an effect size such as (probably in order of preference): smallest effect size of interest; smallest effect size arbitrarily considered 'small', 'moderate', 'large', etc.; a central effect size estimate previously reported in the literature (but be aware this is only the central estimate and is also dependent on many factors in that study); a pilot test (but be aware of limitations in sample size of pilot work and the effect that can have on certainty of effect size estimates). I thin this is a long way of saying sometimes you may input the effect size you expect and other times you may input a different effect size for another valid a priori stated reason. The main thing is to justify the values chosen (including the alpha, beta, and effect size).
Many congratulations. Great presentation. I havent found the study that you present in 39:20 to 43:00 min (flywheel and Smith machine squats - a comparison). Do you have a title or a link? Thanks
Another note, with regard to the interesting discrepancy between forehand trunk speeds of ATP pros and high performance juniors of 16 years old. The professor’s speculative explanatory comment is based once again on some unwarranted assumption like that the technique used by the pros were optimal and/or that there were a linear relation between trunk speed and racquet speed in the upper range of trunk speeds. That is hardly the case in either. It is also highly suspectible that the juniors could generate almost as fast racquet head speeds by ”using upper limbs/shoulder areas” if the pros had optimal techniques utilising efficiently the trunk rotational energy in their forehand speeds. It might rather be argued that the juniors achieve almost the same forehand speed output by much less energy spent by being more relaxed in their arm and shoulder areas than the energy wasting pros: so much work for so scant results! It all can just be due to the pros over-powering the forehand swings by too tight (and muscular and heavy) arms while grunting along! Less is more, guys. Just saying. Learn from the kids.
Important observations posing further questions. The serve seems to be the great unknown forever eluding biomechanical analysis as this analysis conventionally and quite problematically presupposes and takes as a given something that should be addressed first and foremost: What is the optimal, most efficient configuration of the body segements in the load phase/trophy positon (the role and function of different bends, tilts and rotations and the question of their possible sequential coordination and degress of emphasis: back tilt: sommersault (nor squatting!), hip intrusion and the related shoulder tilt: cartwheel, trunk and shoulder/upper arm rotation : spin)? Is it even an intelligible/valid/pedagogically optimal approach to view serve power as a net sum springing out of different power sources attributed to different muscle groups and body parts each of which then allegedly contributing with a given, more or less arbitrary rate (%) to the final product measured in serve speed? What do we even and exactly mean with this loosely used term ”leg drive”? What is its real role in the serve - it should be revisited and by the same token clarified the relation between this so called leg drive and the role of core muscles in the serve dynamics (see the first point above). And finally, related to the critized piecemeal framework allocating rations of serve power to the different body segments, what parts and motions of the body/serve are active generators and what rather passive followers in the complete and optimal service action? This comment also serves as a general (implicit) critique of all such biomechanical models and frameworks that incorporate unproblematically and ”quite pragmatically” these unwarranted putative presumption without addressing such fundamental questions as posed above and thus producing these ”elaborate” multi-phase/stage models like the serve 8-stage model by Kovacs et al. This kind of reductive analytics employed in the conceptualization of harmonized fluid atheltic motions of emergent nature are good at missing the forest for the trees which might even not be not there!
Sir I have grade 1 anterolisthesis so can I continue fast bowling
Hi. I'm definitely not a medical expert and haven't diagnosed anything, so I wouldn't be comfortable giving advice of this type.