ASTN Qld Event July 31st at the Queensland Academy of Sport in Brisbane

IMG_9358The Australian Sports Technologies Network (ASTN) Queensland Node, in conjunction with the Queensland Academy of Sport (QAS) invites you and others from your organisation to the 2014 ASTN (Qld) Node seminar.


The seminar is on Thursday 31 July from 9.00am to 1.00pm at QAS and an invitation with information about the day is attached.


There is no charge to attend but RSVP is essential to allow seating and catering. Please RSVP to Alex Mednis – by Friday, 25 July 2014 if you would like to attend.

Full programme attached

We look forward to seeing you at QAS.

ASTN QLD Node Event 2 – Agenda

What a week – Elite Form, Skill Acquistion, Bowling technology and David Epstein..a huge week for SABEL

Mitch and demo the ICC arm action technology to Cricket Australia high performance team

Mitch, Dan and Jono demo the ICC arm action technology to Cricket Australia high performance team

This past few weeks has been pretty exciting for elite sport up in Queensland and SABEL Labs. First up Chris and the S&C boys at the QAS have just installed a state of the art video based lifting system in the gym. When I say video its actually a distancing video system (like Xbox Kinect uses and then some). Its called Elite Form and used in some of the professional leagues in the states.

Thus lifting in the gym is recorded in a paperless way as athlete moves from station to station. Not only are the weights and the number of lifts recorded, but so to is the rate of the lift. This gives all kinds of information on the quality of the lift which can only be a good thing. Find out more about the system here..
As a researcher its been exciting to see the technology move from an idea first seen at an SPIE conference back in 2006 to exploiting the off the shelf KInect system for game based analysis (See Simons paper ), to now being a pervasive and u obtrusive system in a Gym.
Later on, courtesy of QAS Sports Science, one of Australia’s leading lights in skill acquisition Damien Farrow (AIS and Victoria University) gave an excellent introduction to the field, an overview of  who’s who in Australian Skill Acq. in Australia and well as to adderss some emerging trends, talk about the path to expertise, an an honourable mention for technology. Here a clip of Damien’s work (
David Epstein in Australia

David Epstein at Cricket Australia

Later we presented our wearable illegal arm action technology at the Cricket Australia Science, Coaching and Medicine conference at the newly established National Cricket Centre at Albion, along with Jono and Mitch. It was a veritable who’s who of the coaching and high performance cricket in Australia with a liberal sprinkling of current and past cricket players it was an exciting opportunity to give an update on our world with the ICC in the past few years. Luckily we know our googly from our doosra!

A key note at the conference was David Epstein, author of ‘The Sports Gene’
 who treated us to his take on the 10, 000 hours to proficiency that is much (,mis)used  in the popular press. See his TED talk here. David takes a more biological approach as he looks at the nature vs. nurture arguments among other things.  Turning out he’s a training partner of Outliers’, Malcom Gladwell (another author who has looked at 10,000 hours).  I had the opportunity to have a chat with David over lunch about his work, career and the lively dialogue he shares with Malcom. David was until recently a regular writer for sports illustrated (there goes my opportunity to buy the magazine for professional reasons)
All in all its sad to have to head back to the lab…but a most illuminating week or so!

Announcing SABEL Sense

SABEL SenseAfter a decade or so of working with inertial and other body worn sensors we have had the chance to work with many sports and along the way have developed some in-house tools to enable use to get down to business of data collection a bit quicker and to really hit the ground running. Yes there are products on the market that do this, but they were often application specific, so  we ended up building our own so we could customise many things. Throughout that time we have been asked if they are for sale which was something we never considered as the research was always focused on well research, or a particular product for a client.

Late last year though we were offered some support from the university to come up with a ‘research tool’ that might be useful as a way to build collaboration and field our enquiries. Thus we came up with SABEL Sense, its not quite a product, but a tool that exists in the middle for trying out ideas and an intermediary to development of a final product.

The hardware, whilst nothing special, contains the usual inertial sensors, has a breakout capability for other sensors and is run by a small operating system so it can be customised rapidly. Married to that is a set of Matlab tools for wireless data transfer, synchronisation of multiple units, together with other sources, such as MOCAP and video. We went for Matlab because its easy to change and the performance is good enough for development.

Get Some

It proved popular with several universities already use the tools. If you would like to find out more goto our SABEL Sense page or contact Ray ray(AT)


See us in the next few weeks, where a few of our papers use the technology at

International Sports Engineering Association ISEA Engineering of Sport in the UK

International Association of Computer Science in Sports IACSS 2014 Conference




Of Racing Suits and Aerodynamics

Wind Tunnel tests with custom designed mannequins and different Under Armour speed skating suit prototypes.

In many sports that involve high speed movements, drag or air resistance is probably one of their biggest enemy in achieving their peak performance. One winter sport that faces this challenge is speed skating, and turns out altitude plays a big part as well – the higher the skating venue is, the less air resistance there is (more about that in this article). Also the effect of drag on the skater’s speed and performance is pretty significant and the suit that the skaters wear could have an impact on the colour of the medal they get.

So just before the 2014 Sochi Winter Olympics, there was a bit of news about the revolutionary speed skating suit designed and made by Under Armour and Lockheed Martin. The “Mach 39″ was supposed to be the fastest speed skating suit ever made. Unfortunately, instead of delivering medals (gold ones for that matter), the result was the US athletes performed below expectations. Now, this could be due to the suit OR if we break it down, could be due to a thousand other reasons (on top of the suit).

There was a bit of history to the design of the suit, and the basic idea was: just as dimples on golf balls reduced aerodynamic drag, adding dimples on the suit would have the same effect. Of course, other than the dimple design, there were other considerations like textile selection and compression fitting design. Just have a look at the video below that describes what the designers and researchers looked at to reduce friction and improve aerodynamics of the suit. What’s really interesting is how they customised the mannequins to typical skating positions for wind tunnel tests. (Drag to 4:00 of the video to just see the custom mannequins)

Although the rational behind the design and testing all seems to make sense, I can’t help but have a few questions:

a. With so much movements during speed skating, is it really possible to estimate the drag based on wind tunnel experiments? I mean, there are a number of sports that do drag tests in wind tunnels; like skiing and cycling. But these sports have moments of competing when the athlete maintains a certain position for a short period; and those are the moments where having an optimum position (aerodynamically) could really reduce drag significantly. But speed skaters hardly stay in one position during competition (maybe except at the starting line). Then if that’s the case, would the wind tunnel results be fully applicable on the track?

b. Friction plays 2 roles: it slows you down and it gives you more grip/control. If there is too much friction, it impedes movement; but if there is minimal or close to no friction, the athlete might lose control. How then, do we strike a balance between them?

c. Is it possible to measure drag dynamically on the track? Well, a company called Alphamantis seems to have done that, but with cycling, and in a velodrome fitted with gate sensors. Some additional input parameters they require include the bike’s wheel circumference and also inputs from standard power meters and speed/cadence sensors. With the power meters, there is a calibration process before the actual ‘aerotesting’ where they apply a model to calculate drag. For more details of the testing, you can read this interesting blogpost by DCrainmaker.

I reckon it is possible (in theory) to develop a model for speedskating (similar to what Alphamantis did for cycling) to estimate drag on the ice skating track. The model might be slightly similar to this one in wheelchair racing: when the speedskater is pushing off (and at equilibrium), there are 4 different forces applied on the speedskater: 1) Reaction force, 2) Inertia, 3) Friction between the ice and skates, and 4) Drag force.

  1. Reaction force (or applied force) can be measured by instrumenting the skates with a shoe sole pressure sensor similar to this or this.
  2. Inertia can be determined by measuring the forward acceleration of the skater (using an inertia sensor or a suit of sensors), then multiplying that by the overall mass of the skater.
  3. Friction can be calculate based on the coefficient of friction of ice which is different for straights and curves according to this paper.
  4. Finally, since the sum of all these forces equals to zero, we can determine the drag force!

Xsens Concept Tests in Speedskating

Of course this model is very much simplified and some assumptions are made, but if more thought is put into it, this might just work.

Anyway, going back to the lacklustre results of the Under Armour Mach 39 suit, there could be so many reasons why the athletes didn’t perform during those races. Since US speedskating has extended the contract with UA, they obviously know that the suit wasn’t the main culprit. It did sound like the athletes weren’t really used to the new suit, so maybe at the end of the day, it’s just a matter of ‘breaking-in’ the suits.

Thanks for reading and if you have any thoughts or suggestions on aerodynamics or drag tests, do leave some comments!


Inaugural Best Paper award, Velocity profiling using inertial sensors for freestyle swimming

adat-in-actionCongratulations Andy on winning the inaugrall Best paper of the year award in the prestigous Journal of Sports Engineering.

It is the culmination of many years of work towards Dr. Stamm’s PhD. We look forward to hopefully seeing you at the ISEA Engineering of Sport conference later in the year to accept your award

Sports Engineering
March 2013, Volume 16, Issue 1, pp 1-11
Velocity profiling using inertial sensors for freestyle swimming
Andy Stamm, Daniel A. James, David V. Thiel
The ability to unobtrusively measure velocity in the aquatic environment is a fundamental challenge for engineers and sports scientists and important in assessing the skill level. The aim of this research was to develop a method for velocity profiling in freestyle swimming utilising a purpose-built inertial sensor. Seventeen swimmers with different experience levels participated in this study performing a total of 159 laps in the velocity range from 0.79 to 2.04 m s−1. Data were collected using a triaxial accelerometer and a tethered velocity meter. The collected acceleration data were filtered using a 0.5 Hz Hamming-windowed FIR filter to remove the gravitational acceleration before the lap velocity profiles were calculated. These calculated lap velocity profiles were then compared with the velocity profiles measured by the velocity meter using Bland–Altman analysis. The scattering follows a normal distribution with a mean skewness of 0.96 ± 0.47 and kurtosis of 2.93 ± 1.12. The results show that an inertial sensor alone can be used to determine a lap velocity profile from single point acceleration records.


See the full article here