Nintendo wii fit can be used as a force plate?

Apparently it is possible to use the Nintendo Wii Balance Board as a measurement device. In fact, the Nintendo wii balance board is a simple force platform capable to sampling data at 100Hz.



The Wii Fit offers for a low cost price a simple platform with four measuring sensors and can be used with very little effort as a simple and inexpensive force plate, even without the corresponding game console. Clark et al. (2010) suggested that the Wii Fit balance board could represent a valid cheap solution to measure standing balance. Furthermore they have recently suggested the use of the infrared cameras in the hand controllers as a possible alternative to expensive timing light systems (http://www.jsams.org/article/S1440-2440(10)00913-8/abstract). Recent work from Young et al. (http://www.ncbi.nlm.nih.gov/pubmed/21087865) also suggests the possibility of using this technology for developing bespoke diagnostic or training programmes that exploit real-time visual feedback of current Centre of pressure position.

The Wii Balance Board is certified for 300 pounds (136 kg) in Japan and 330 pounds (150 kg) in the U.S. The Wii Balance Board has four sensors, so each sensor is certified for up to 136 kg / 4 = 34 kg per sensor in Japan or 150 kg / 4 = 37.5kg per sensor in the United States.The following Wii Balance Board calibration information from WiiBrew will make more sense.

If you are interested in Linux, you can see here how to extract the force data. I am sure this is not something useful to measure high performance athletes. However it could represent a fun and simple tool for diagnostic measurements in some populations.

If you have one and are able to use it for this purpose let me know!

More freeware biomechanical software

I was looking for some freeware or open source software for some biomechanical analysis and came across two software solutions developed by video4coach.
The two solutions are quite interesting and very good quality. The first software is called Skill Capture

SkillCapture is designed to capture video clips which can be directly associated with the athlete also by means of a radio frequency ID system (skillchip).
Video capture can be started by:

• Motion detection
• SkillChip registration
• SkillChip registration and Motion detection.
• Pressing keyboard shortcut
• Using wireless presenter

After video capture it can be automatically displayed for coach interaction directly with the athlete. With the video playback its possible to:

• Adjust playback speed (0.5 - 2.0 of normal speed)
• Rate performace
• Mark for upload
• Draw angle to show body positions
• Freehand drawing

SkillCapture will automatically compress the video to improve storage and improve faster upload to external servers.
The other solution is SkillSpector.

SkillSpector is a video based motion and skill analysis tool for Windows. SkillSpector is freeware and can be downloaded and installed on any computer.
SkillSpector features:

• Video overlay for direct video on video comparison
• 2D and 3D analysis
• Standard model definitions for fast analysis
• Semi-automatic digitizing using image processing techniques
• Easy advanced analysis of linear and angular kinematic data
• Calculation on inertia
• 3D representation of movement
• Simple video calibration

So, two software packages completely free which I am sure can be of help for many sports scientists in the field not able to access the expensive professional software solutions currently available on the market.
I have just installed the software and I will write something more about them after I get the chance to experiment with them a bit more.

New article published

Finally, our review on the role of Testosterone and Cortisol in modulating training responses in athletes has been published on Sports Medicine.

 

Here are the details:

Sports Med. 2011 Feb 1;41(2):103-23. doi: 10.2165/11539170-000000000-00000.

Two Emerging Concepts for Elite Athletes: The Short-Term Effects of Testosterone and Cortisol on the Neuromuscular System and the Dose-Response Training Role of these Endogenous Hormones.

Crewther BT, Cook C, Cardinale M, Weatherby RP, Lowe T.

The New Zealand Institute for Plant Food Research Limited, Hamilton, New Zealand.

Abstract

The aim of this review is to highlight two emerging concepts for the elite athlete using the resistance-training model: (i) the short-term effects of testosterone (T) and cortisol (C) on the neuromuscular system; and (ii) the dose-response training role of these endogenous hormones. Exogenous evidence confirms that T and C can regulate long-term changes in muscle growth and performance, especially with resistance training. This evidence also confirms that changes in T or C concentrations can moderate or support neuromuscular performance through various short-term mechanisms (e.g. second messengers, lipid/protein pathways, neuronal activity, behaviour, cognition, motor-system function, muscle properties and energy metabolism). The possibility of dual T and C effects on the neuromuscular system offers a new paradigm for understanding resistance-training performance and adaptations. Endogenous evidence supports the short-term T and C effects on human performance. Several factors (e.g. workout design, nutrition, genetics, training status and type) can acutely modify T and/or C concentrations and thereby potentially influence resistance-training performance and the adaptive outcomes. This novel short-term pathway appears to be more prominent in athletes (vs non-athletes), possibly due to the training of the neuromuscular and endocrine systems. However, the exact contribution of these endogenous hormones to the training process is still unclear. Research also confirms a dose-response training role for basal changes in endogenous T and C, again, especially for elite athletes. Although full proof within the physiological range is lacking, this athlete model reconciles a proposed permissive role for endogenous hormones in untrained individuals. It is also clear that the steroid receptors (cell bound) mediate target tissue effects by adapting to exercise and training, but the response patterns of the membrane-bound receptors remain highly speculative. This information provides a new perspective for examining, interpreting and utilizing T and C within the elite sporting environment. For example, individual hormonal data may be used to better prescribe resistance exercise and training programmes or to assess the trainability of elite athletes. Possible strategies for acutely modifying the hormonal milieu and, thereafter, the performance/training outcomes were also identified (see above). The limitations and challenges associated with the analysis and interpretation of hormonal research in sport (e.g. procedural issues, analytical methods, research design) were another discussion point. Finally, this review highlights the need for more experimental research on humans, in particular athletes, to specifically address the concept of dual steroid effects on the neuromuscular system.

Monitoring training load: the sum of all parts

Finally a little bit of spare time to do some blog writing. I have discussed the issues of monitoring training loads in my previous posts #1,#2,#3.

Also, I have written a previous post on strength and power assessment and vertical jumping tests.

So, I am not going to discuss testing techniques here, but rather discuss what monitoring is all about and how to use it and offer some solutions/ideas.

Monitoring is definitively a sexy topic as everyone seems to be “monitoring” something in training. To the extent that some athletes are also now flooded with questionnaires, spreadsheets, forms to fill in. Most of such information I have to say it is totally useless as it does not get used and/or is totally irrelevant for designing better training programmes.

Why testing and monitoring training then? First principles first:

 

Testing and monitoring are useful tools only if they allow you to analyse the athlete’s level and be able to define and adapt a training programme.

If you are measuring something that does not help you in modifying the training plan you are wasting your time!

Also, you should make sure you measure things using methods that are valid and reliable! For more information about validity and reliability I suggest you read Will Hopkins’ excellent blog here. If you use measurement tools and modalities that are not valid and reliable you are wasting your time!

Testing and monitoring are tools to help you in making better decisions with your training planning. They are not standalone activities and you should question everyone of them in terms of cost effectiveness not only in financial terms but also in terms of athletes’ time. I have seen in too many sports athletes filling too many questionnaires and forms that are neither valid nor reliable nor provide any meaningful info to the coaching staff.

Planning training is just like business. Testing and monitoring will tell you where you are now. Strategic planning, analysis of specific performance trends (or world trends) and goal setting will help you in defining where you need/want to be. The how you get there is your training plan. If testing does not help you in getting a better HOW, it is just a useless data collection exercise.

 

 

 

 

 

 

 

 

 

 

Most of all, a proper approach to testing and monitoring can make sure you avoid insanity and learn what works and what does not work with you athletes.

So, what should be the approach?

In my view it is relatively simple. You need to be able to collate all the information you decided to collect, analyse it, make some sense of it and build a “dashboard” to visualise what is going on in order to be able to intervene where necessary. One of the approaches I suggested previously involves the use of radar charts to profile each individual athlete in comparisons to team scores. Similar approaches can be used even with individual athletes just comparing the magnitude of changes in their own scores:

 

However, a more comprehensive view could be obtained using what I call a “performance equaliser”. The example below shows how some specific scores ca be plotted with an equaliser dashboard and visually show how specific parameters can change during a training season.

Performance Equaliser #1: Beginning of training phase

Performance Equaliser #2: After few weeks

This approach can be used to evaluate each athlete’s situation and take appropriate action as well as providing an easy to understand reporting structure. I have used green and red to express good change and not so good change.

Good, continuous data can also help in having a more complex data analysis approach involving the possibility of data modelling and simulation to be able to predict some outcomes. The example below from Busso et al. (2007, JAP) is just an example of the scientific literature on modelling.

This is one of the areas I am working on as I have a keen interest in computational statistical models applied to training and performance data and I have to say that there is very limited information on this topic and the few experiments also have very limited samples sizes (I found a couple of paper with n=1!). A review of the literature is now planned and I hope it will be ready for 2011 thanks to the hard work of an excellent PhD student working on this topic in my lab.

Many companies are now offering all sorts of software to analyse data using typical modelling approaches such us decision trees, Monte Carlo methods, etc. However it is important to state that the quality of the analysis is as good as the data you collect. So, again, you get what you put in it. Also, if your data are wrong, you will definitively make the wrong calls!

Despite the fact that simulations and data modelling have a certain degree of error (from very very large to relatively small), I still believe that this is something to pursue as I believe that nowadays some good continuous basic data can be collected and they can provide some useful information. As Richard Dawkins stated in his book “The Selfish Gene” “[…] of course there are good models of the World an bad ones, and even the good ones are only approximations. No amount of simulation can predict exactly what will happen in reality, but a good simulation is enormously preferable to blind trial and error!” R. Dawkins (2006).

Another useful approach can be the use of simple mathematical/financial laws as the Law of Diminishing Returns. The law of diminishing returns states that as the quantities of an input increase, the resulting rate of output increase eventually decreases.

This is exactly what we see in training. We increase and decrease training volume and intensity and we see changes in performance (output) which increase or decrease if we do too much work.

Recent work from my colleague Dr. Brent Alvar’s lab have shown how such approach can be used to analyse for example the effectiveness of strength training following a meta-analytical approach (for more info, click on the graph below).

Despite the fact that others criticised this approach for analysing the effectiveness of multiple vs. single sets using literature data, I believe that such approach can and should be used to understand the effectiveness of a training programme (or the return for your investment in time and effort). This should help in understanding the dose-response relationship to training loads in your athletes.

I am sure I have not covered a lot of aspects, and I am sure I will change my mind about a few of the things I wrote in the future (this is what learning is all about!). But at the moment I feel that monitoring training is a very useful thing to do and some statistical approaches can be applied to extract useful information to translate analysis into actions.

So, to summarise, here is some advice:

- Are your tests valid and reliable?

- What is the error of measurement? (What is the noise of your data?)

- What are you measuring?

- Are you able to use the data you gather to action changes to the programme?

- What is the investment in time/costs/effort to collect the data? Is it worthwhile?

_ How long does it take to receive the data in order to analyse them? (e.g. blood tests tend to be analysed few days after you collected them)

- Can you collect some valid, reliable, non subjective data with high frequency?

- Are the data good enough and frequent enough to allow you to make some predictions?

Strength and Conditioning Book

They say better late than ever, in this case it took few years, but eventually the project is now completed and the book will be out on the 17th of December.
It all started with a chat at a conference few years ago with my colleagues and friends Rob Newton and Ken Nosaka discussing the need of a comprehensive textbook on strength and conditioning providing information on the biological bases as well as practical applications.
This book is finally a reality thanks to the help and support of many colleagues who agreed to contribute to this project providing excellent chapters and creating a unique resource which we hope will be well received by anyone interested in Strength and Conditioning.

This book provides the latest scientific and practical information in the field of strength and conditioning. The text is presented in four sections, the first of which covers the biological aspects of the subject, laying the foundation for a better understanding of the second on the biological responses to strength and conditioning programs. Section three deals with the most effective monitoring strategies for evaluating a training program and establishing guidelines for writing a successful strength and conditioning program. The final section examines the role of strength and conditioning as a rehabilitation tool and as applied to those with disabilities.
The book is already available on Amazon and other online booksellers in hardcover and paperback editions.
A big thanks to our production team at Wiley-Blackwell and all the colleagues contributing to the chapters.

Details of the chapters are available here:
Foreword (Sir Clive Woodward).
Preface.
1.1 Skeletal Muscle Physiology (Valmor Tricoli).
1.2 Neuromuscular Physiology (Alberto Rainoldi and Marco Gazzoni).
1.3 Bone Physiology (Jörn Rittweger).
1.4 Tendon Physiology (Nicola Maffulli, Umile Giuseppe Longo, Filippo Spiezia and Vincenzo Denaro).
1.5 Bioenergetics of Exercise (R.J. Maughan).
1.6 Respiratory and Cardiovascular Physiology (Jeremiah J. Peiffer and Chris R. Abbiss).
1.7 Genetic and Signal Transduction Aspects of Strength Training (Henning Wackerhage, Arimantas Lionikas, Stuart Gray and Aivaras Ratkevicius).
1.8 Strength and Conditioning Biomechanics (Robert U. Newton).
2.1 Neural Adaptations to Resistance Exercise (Per Aagaard).
2.2 Structural and Molecular Adaptations to Training (Jesper L. Andersen).
2.3 Adaptive Processes in Human Bone and Tendon (Constantinos N. Maganaris, Jörn Rittweger and Marco V. Narici).
2.4 Biomechanical Markers and Resistance Training (Christian Cook and Blair Crewther).
2.5 Cardiovascular Adaptations to Strength and Conditioning (Andy Jones and Fred DiMenna).
2.6 Exercise-induced Muscle Damage and Delayed-onset Muscle Soreness (DOMS) (Kazunori Nosaka).
2.7 Alternative Modalities of Strength and Conditioning: Electrical Stimulation and Vibration (Nicola A. Maffiuletti and Marco Cardinale).
2.8 The Stretch–Shortening Cycle (SSC) (Anthony Blazevich).
2.9 Repeated-sprint Ability (RSA) (David Bishop and Olivier Girard).
2.10 The Overtraining Syndrome (OTS) (Romain Meeusen and Kevin De Pauw).
3.1 Principles of Athlete Testing (Robert U. Newton and Marco Cardinale).
3.2 Speed and Agility Assessment (Warren Young and Jeremy Sheppard).
3.3 Testing Anaerobic Capacity and Repeated-sprint Ability (David Bishop and Matt Spencer).
3.4 Cardiovascular Assessment and Aerobic Training Prescription (Andy Jones and Fred DiMenna).
3.5 Biochemical Monitoring in Strength and Conditioning (Michael R. McGuigan and Stuart J. Cormack).
3.6 Body Composition: Laboratory and Field Methods of Assessment (Arthur Stewart and Tim Ackland).
3.7 Total Athlete Management (TAM) and Performance Diagnosis (Robert U. Newton and Marco Cardinale).
4.1 Resistance Training Modes: A Practical Perspective (Michael H. Stone and Margaret E. Stone).
4.2 Training Agility and Change-of-direction Speed (CODS) (Jeremy Sheppard and Warren Young).
4.3 Nutrition for Strength Training (Christopher S. Shaw and Kevin D. Tipton).
4.4 Flexibility (William A. Sands).
4.5 Sensorimotor Training (Urs Granacher, Thomas Muehlbauer, Wolfgang Taube, Albert Gollhofer and Markus Gruber).
5.1 Strength and Conditioning as a Rehabilitation Tool (Andreas Schlumberger).
5.2 Strength Training for Children and Adolescents (Avery D. Faigenbaum).
5.3 Strength and Conditioning Considerations for the Paralympic Athlete (Mark Jarvis, Matthew Cook and Paul Davies).

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