Sports technology aids athletes quest for gold medals

The lengthy, arduous training campaign for the Olympics is over, and for the athletes selected for Team GB the time of reckoning is upon them as their quest for medals begins. However, their brief foray at the Games itself is only the tip of their exertion.

According to Professor Steve Haake, director of the Centre for Sports Engineering Research (CSER) at Sheffield Hallam University, success at gold medal standard is not just one singular thing, but a combination of lots of little things together which makes the difference. Dave Brailsford, performance director at British Cycling has coined the phrase "The aggregation of marginal gains" to describe the approach of finding a 1 per cent margin for improvement in everything you do.

UK Sport is the government body responsible for investing around £100m in Britain's best Olympic and Paralympic sports, with the aim of maximising success on a world stage. Some of that incremental gain will come through the intelligent use of technology and, as a UK Sport Innovation partner of the Olympics, the team at Sheffield Hallam CSER have trialled their new technology with over a dozen Olympic sports in the lead up to the Games.

Prof Haake explains how the last three decades have been "very much about the design of equipment, materials and structures. Since then computer power has improved, along with portability and camera resolution, so we have the ability to collect more and more information. I would say that 2010 onwards is going to be all about data capture and feedback".

Sheffield is the home to the English Institute of Sport (EIS) and the GB Olympic boxing squad. Here, Prof Haake and his team have set up a gym equipped with a camera capture system to assist in coaching and talent identification. There are five rings in the gym, one fitted with a plan view camera, another with a pan, tilt and zoom camera, which can focus anywhere in the gym, and a further two cameras focused on specific rings. There is also a touchscreen system with fitted consoles spanning the length of the gym.

Once an athlete has completed a three-minute round or training workout, they can immediately obtain video feedback on that particular session. The video data is loaded onto a database which also stores live tournament video, scores and information on a particular athlete and their opponents' strategies, all available on one system.

Prior to this streamlined computerised system a coach would have to halt the session while they downloaded video footage, meaning the immediacy of their coaching was lost. With this system the coach is able work more efficiently and effectively as the technology does all of the processing internally.

"What this technology has done for coaching is much like what the iPhone, iPod and iPad has done for usability of the Internet," says Prof Haake. "We collect an awful lot of data, but we don't necessarily show all that we collect, only that which is useful to the athlete and coach at that moment in time. We might do something with it later or report it behind the scenes, but the immediate feedback you get tends to be relatively simple."

Formatting feedback

This system has taken 18 months to develop. The team had to overcome a number of difficulties, including achieving high enough camera resolution, improving data transfer and optimising data storage for the terabytes of information.

Equally critical was developing the software interface to be as simple as possible in order to give immediate feedback to the coaches and the athletes in a useful format. To achieve this, high-resolution machine vision cameras running at 200Hz are used, downloading via Ethernet or wireless to a secure database. This can store any type of information such as word files, video or tagged data. Video data can now be compressed up to 90 per cent without appreciable loss of resolution.

The primary access to the data and video is through the gym's centralised touchscreen consoles so that the coach or athlete is able to get direct information feedback wherever their location. The system is set up so any mobile device, including the iPhone and iPod Touch, can access the information using the wireless network.

The coaches and athletes can now obtain a real-time set of performance metrics, including scores, movements and strategies. In the gym there are multiple touchscreens showing video footage of the fight as it takes place, combined with tournament information such as the boxers name, origin, height, weight, scores in each round, and details of the winning athlete. This data allows the coach to determine the success rate of an athlete against a potential opponent.

"Using the system you have the capability to go and do a training session and work on specific strategies for the upcoming bout. Everything we do is about getting more gold medals" says Prof Haake.

Loughborough University Sports Technology Institute (STI) also works with a number of GB Olympic sports teams, including British Swimming. A new product, introduced by the worldwide governing body of swimming, just after the Beijing Olympics, will be used for the first time at the 2012 London Olympics. A new starting block with adjustable slanted wedge at the rear allows the athlete to alter the wedge position to one of five default settings, swap the front and rear leg, and alter other elements of the posture such as the foot width. The potential variables of new start block from FINA have introduced a level of uncertainty into the competition, leaving many coaches unsure about what is best for each individual athlete.

Data acquisition

To help coaches make an informed decision into how the equipment can be used effectively, Professor Michael Caine at Loughborough University has integrated force transducers into the new starting blocks. With transducers in both the main platform and the wedge, the team can record the force generated by each of the athletes' legs as they push off on the two sections of the platform.

Data acquisition is provided by a laptop, which can also collect high-speed video and data from underwater markers. "It is OK just to take measurements from the forces of the dive, but unless you know the outcome of the dive, such as how fast someone entered the water and at what angle, you can't say if it was a good, bad or indifferent dive," says Prof Caine.

To achieve this, the team have integrated further technologies including electronic accelerometers and gyroscopes fitted to the swimmer, but typically video, markers and nodes are used enabling them to quantify the dive. The athlete's body is tracked both in air and underwater, using either active or passive markers. These are usually placed on well-defined bony prominences on the body that won't move around too much, such as the femur head at the hip or a knee joint. From there a 'stick person' can be created in the software to compute the joint angles.

The disadvantage of passive markers, which tend to just be reflective, is that you need to track them through a process of digitisation once you have captured the film. Active markers such as LEDs, which emit light rather than reflecting it, have also been tried. Unlike the passive markers where you do a lot of digitisation by hand, active markers have a higher contrast and image recognition software can be used to subtract the foreground from the background and automate that process. This makes the process faster and removes the human element, allowing the team to provide coach and athlete feedback in near real-time.

"We are moving along a continuum where the end goal is that everything is real time, that is in the time it takes an athlete to get out of the pool and walk around to sit beside their coach" says Prof Caine.

The Loughborough team have built an experimental protocol whereby they don't look at the extremes, but at the settings most likely to be optimal and compare them. This is not about a scientific study but an optimisation process for the elite athletes. "Once you think you have identified the best setup, the athlete keeps working on that and you keep monitoring their performance. What you are hoping is that it is consistently better than what they were doing before," explains Prof Caine.

Individual performance

Loughborough STI has also been working on a long-term project analysing the bending stiffness of sprint spikes for runners. The bending characteristic of sprint footwear varies hugely and some commercially available spikes can be two or three times more stiff as the next.

At the moment athletes pick what they feel comfortable wearing. However, a biomechanics group from Calgary University have looked at bending stiffness related to the kinematics and kinetics of sprinting and suggest that individual athletes will have an optimum shoe-bending stiffness. "We have tried to come up with a methodology whereby we can ascertain what the stiffness level is for any given athlete and then make those shoes. We can then compare less stiff and more stiff to see if they do indeed perform at their best in the shoe that we believe is optimal," says Prof Caine.

Working with their partner New Balance, Loughborough University now have the technology and capability to make sprint spikes from scratch. They can produce spikes which allow them to determine the bending stiffness in accordance to their own designs, with integral traction features eradicating the need to screw in the spikes manually.

They have developed methodologies that allow them to put an athlete through a battery of tests which will suggest what stiffness of shoe they ought to be wearing to improve their performance. In some cases, they are making shoes three or four times as stiff as you can buy and still finding that athletes are running equally as fast if not faster than in the shoes they are traditionally used to wearing.

In a quest for incremental optimisation, the team is looking to measure ground contact time, stride length and time, and other factors like joint angle or ankle rotation. They are working with a number of sub world-class athletes capable of running 10.8 seconds for 100m and measuring their performance in shoes of different stiffness.

Unfortunately for elite athletes, the shoes they wear are largely dictated by individual and team sponsorship deals. It is therefore likely that the immediate gains for this work will be showcased in Paralympic and disability sports. Correcting gait abnormalities caused by an athlete's underlying condition can enable them to train in an injury-free environment or at a higher intensity.

Loughborough STI is working with Ben Rushgrove, one of Britain's best-known Paralympic sprinters, who has suffered with repeat foot injuries. They have used the technology to customise the stiffness, geometry, stabilisation and cushioning of his shoes. Instead of adding orthotics, they were able to make the shoe incorporating the optimal features at the point of manufacture, thus modifying the stiffness and hopefully reducing injury.

The work was funded by a project called 'Personalised Footwear from Elite to High Street', with the long-term goal of making personalised sports shoes accessible for everyone. Previous changes in sports shoes have come from insights gained at the elite level and then migrated into mass production.

"Customisation and personalisation in sporting goods is a very significant trend and all the big manufacturers already offer something in that space, but are so far driven by aesthetics and not by functionality. It will happen – it is just a case of when, rather than if," says Prof Caine.

In the future, by changing the mechanical stiffness and properties of the shoe to suit an individual's requirements in a cost-effective way, we should see a whole host of benefits. This includes reducing the risk of injury or the discomfort from running or other sports and will hopefully inspire the public to become more physically active.

Next time you lace up your running shoes, just imagine what they would be like if they were designed to your personal training requirements and biomechanics. Usain Bolt is unlikely to be worried, but for the next generation of athletes it might improve their chances of bringing home a coveted gold medal. 

Further information

• Sheffield Hallam Centre for Sports Engineering Research
• Loughborough Sports Technology Institute
• FINA
• UK sport
• Paralympics GB
• British Olympic Association

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