杏吧原创

MY GOLF swing is wonky. The backswing isn鈥檛 so bad, I suppose, but it鈥檚 my follow-through: it鈥檚 all over the place.

At least, that鈥檚 the painful feedback I鈥檝e gleaned from SwingReader 鈥� an iPhone app that uses video to help pinpoint flaws in the average golfer鈥檚 game. Alongside runners鈥� apps, it鈥檚 just one of the new ways amateurs can now get technical help and analysis of the kind that, until recently, had only been available to the professionals.

SwingReader, from start-up tech firm , lets amateurs load videos of their own swing and compare it with footage of professional golfers to see where they are going wrong. In December, computer vision algorithms will be added to the app so that individual objects in the frame 鈥� such as the golf club鈥檚 head 鈥� are tracked automatically.

鈥淵ou can identify objects within the video without the user having to wear sensor nodes on their body,鈥� says the firm鈥檚 Amit Jardosh. 鈥淭his has never been done on a mobile phone before.鈥�

聯You can identify objects within the video without having to use sensor nodes on your body聰

Smartphone sensor packages 鈥� which increasingly include an accelerometer and gyroscope 鈥� mean they can be also be strapped to an athlete and used to record detailed biomechanical data, such as a runner鈥檚 stride. But carrying out analysis on a cellphone is impractical. 鈥淧rocessing this data chews up a tonne of battery power,鈥� says Tristan McNab of Griffith University in Brisbane, Australia.

So McNab is working on an iPhone platform that logs the athlete鈥檚 movements using the smartphone鈥檚 built-in sensors but then uploads the data to cloud servers via Wi-Fi for the heavy number-crunching.

Users have an account that allows them to access a suite of analytical tools online. 鈥淏y offloading calculations to the server, we save the user battery power and they may only need to buy a single app,鈥� says McNab.

But all of this data is useless to athletes unless it鈥檚 delivered in a 鈥渞easonable and rational way鈥�, says Richard Wheater, head of coaching for England Athletics.

For example, an amateur runner may not know what to do with a system that says 鈥測our foot is pronating 32 degrees when it hits the ground鈥�. Simpler instructions like 鈥渢ry lifting your knees鈥� could be more helpful.

鈥淵ou鈥檝e got to remember it鈥檚 the quality of interpretation that counts,鈥� he says.

For this reason, UberSense鈥檚 product still requires someone to view the video frames and make recommendations to the athlete.

Beyond apps, researchers are also turning to devices known as inertial measurement units (IMUs). at the Massachusetts Institute of Technology in Cambridge has developed the sportSemble system, which uses IMUs to analyse how baseball pitchers throw the ball. Each unit contains an accelerometer, gyroscope and magnetometer to measure strength and direction of magnetic field, similar to those found in an iPhone. One is attached to the pitcher鈥檚 hand, wrist, upper arm, chest and waist.

IMUs are much more sensitive than the iPhone鈥檚 sensors 鈥� the IMU accelerometers can record forces up to 120 g created as an athlete goes through his pitching motion, for example. Lapinski is working with a Major League Baseball team (he won鈥檛 say which one) to catalogue how their star pitchers manage to dominate the league鈥檚 best hitters. Such data could also help amateur players improve their game.

IMUs could even help those looking to improve their regular jog. at the Swiss Federal Institute of Technology (ETH) in Zurich has attached sensors to a runner鈥檚 hip and foot to distinguish between the contrasting running styles of novices and those more experienced. Currently, optical tracking is used to monitor a runner鈥檚 gait. This requires expensive equipment and limits the analysis to an indoor treadmill. 鈥淓ven professional athletes don鈥檛 have regular access to these systems, they are so expensive,鈥� says Stohrmann.

Data collected from the sensor units picks out how each runner鈥檚 foot hits the floor, whether it is toe first (better for sprinters) or a mid-foot stride (for long-distance runners). It also measures heel lift and length of sole contact with the ground.

Stohrmann says her system, presented at the conference in Beijing, China, in September, could be used like an advanced version of pedometer kit Nike+ to give biomechanical feedback and tips to amateur runners via a smartphone app.

Andy Harland, head of the sports technology research group at Loughborough University, UK, says the increase in performance from such devices will likely be more dramatic in novice athletes than professionals. 鈥淪ome kind of law of diminishing returns would apply here,鈥� he says. 鈥淪ome basic intervention is likely to allow a novice to develop a golf swing or running style to a reasonable level fairly quickly. However, much more sophisticated analysis methods and interpretation would be needed to allow an elite athlete to improve by a much smaller amount.鈥�

In other words, all the fancy new measurements probably won鈥檛 make you as good as a pro. But they should at least level the playing field.