Video analysis for the masses

Video from any video camera can be used for analysis, even a camera phone

Anyone who has attended an elite swimming meet, be it a national championships or a world championships, can’t fail to have noticed the bank of cameras positioned at the back of the gallery capturing every stroke and splash that goes on in the pool. The film taken by those cameras is taken away and analysed in order than coaches can measure every aspect of a performance, be it the length of a dive, the amount of time spent underwater or the peak velocity that a swimmer reached during the race.

This data allows a qualitative judgement to be made on a performance and areas of improvement or indeed areas that have deteriorated to be identified. For example, a swimmer may be working on increasing their distance per stroke with an aim of increased efficiency and speed by reducing the number of stroke cycles per length in a race. The race stats will tell the coach and swimmer whether it worked and by comparison with a swimmer’s best performance can even allow for some normalisation against outside factors, such as training load. For example a time may be slower but some aspect of the swim may have demonstrated the desired improvement.

As well as racing, video is used extensively at the elite level in stroke analysis, with a variety of bespoke camera systems available. Indeed British Swimming has recently installed a travelling overhead camera at the EIS pool in Loughborough that tracks a swimmer from above, allowing deviations in a swimmers progress to be identified. As Jodi Cossor, British Swimming’s Biomechanist explains “We can replicate racing to see what happens to the stroke at each point of the race, from start to finish, specifically when the swimmer gets tired.”

“Our coaches can look at the stroke mechanics and can track the swimmers’approach to the wall. We can see which lines they are taking so we can work on maintaining a straighter line to turn more economically to keep their momentum.”

Not everyone has access to such high tech wizardry, but most club swimmers will benefit from some analysis of their races, if only to identity areas for future work or flaws in their technique under pressure. Sitting with a coach and reviewing a video of a race or a specifically shot piece of stroke footage will of course reap rewards but won’t provide the detailed numbers that a bespoke analysis will. However, a new system being launched by Olympic medallist Nick Gillingham MBE is hoping to change that situation.

Gillinhgam’s SwimOptimum project allows anyone to access the kind of race analysis that the elite are using from their personal computers. Any race video can be loaded, even one from an iPhone or similar, provided a view of the swim is maintained so that the user can set the various checkpoints needed by the software to deliver a race analysis report. That output is in accordance with National Team standards, reporting stroke distance, cadence, breakout distances, turn time etc. in exactly the way that national federations would expect, hence providing information that coaches can use to identify weaknesses and improvements. It will soon also be possible to complete the analysis direct from an iPhone itself, allowing almost immediate feedback.

An example SwimOptimum race analysis report (click to enlarge)

“We’ve really developed this system to help those who aren’t funded through national teams and the national lottery. Not many swimmers are lucky enough to be supported by British Swimming or their national federations” says Gillingham. ”This technology allows anyone to get a detailed race analysis in around 7 minutes for a 100m event.”

The site also has a technique analysis module that highlights key points to identify throughout each stroke, with video examples from elite swimmers available to highlight the ideal technique. Given the level of information available, both written and video, it’s clearly aimed at swimmers as well as coaches. Conceivably the analysis could be used by anyone looking to improve their swimming; a ‘self-analysis function’ for swimmers links into technical information without the need to score or rate aspects of the stroke, but qualititative measurement is possible.

“We have a set of core objectives for each stroke against which strokes are measured” explains Gillingham.”Each is rated to give an overall score betwen 100 and 1000. This allows a swimmer’s improvement to be measured and also for the weakest areas to be targeted for improvement.”

Users also have the option of having their stroke analysed by a resident expert coach but could this be seen as cutting across home coaches? “Any scores or comments as well as video and written content within the system to support the report is based on swimming efficiency and what sports science has concluded is effective, we simply want to support home coaches. Reports can be printed off and discussed with a coach of course. We have a number of clubs already using the system and home coaches have found this approach valuable” is the response. “So the option of an independent analysis by a SwimOptimum coach is there but the tools can be used by home coaches with their own swimmers.”

In this age of the internet, it’s not surprising that a tool such as SwimOptimum now exists, but it’s certainly welcome. While it can’t make an Olympic champion overnight, swimmers around the country can now take advantage of the kind of support that would ordinarily have been the preserve of those at the highest level, giving them the opportunity to get the most out of their swimming.

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