The teenage girl in the gym pauses briefly, readying her body and mind for the surge of action ahead, before launching herself on the short run up to the high bar. Accelerating rapidly, she soon soars over easily, head and shoulders leading.
In the brief time it takes her to rise from the mattress and walk to the side of the hall, the laptop computer has already processed the video images from the tripod-mounted camera and is playing them back on a projector screen, all without teacher intervention.
Shelley McElvie, a fourth year pupil at Menzieshill High in Dundee, studies the high jump she has just performed. "I need to get my hips higher," she decides.
"It's great that you can see what you have done as soon as you've done it, instead of listening to somebody trying to tell you."
The imaging and analysis package the Higher PE pupils are using has already been proved by elite athletes in many sports, says Kevin Taylor, the Scottish representative of the US company Dartfish. "Over 100 medal winners at the last Olympics were trained using Dartfish software. This good stuff at the upper levels of sport is now filtering down to school PE. It is what, as a former principal teacher of PE, first captured my interest."
While the software is already being used in dozens of Scottish schools - and hundreds around the UK - Dundee City is the first authority to buy licences for all its 10 secondaries, says Mr Taylor.
"The pupils get instant visual feedback. Then they can use the built-in measuring tools to analyse their performance in detail," says Dundee's sports development officer, Dave Nicoll.
"It gives them evidence of their performance as they progress.
"They can play themselves in action at the beginning and end of a programme, side-by-side on the screen, and then compare and contrast their performance. It's an amazing piece of kit."
Key elements in the Dartfish package for schools include digital video recording, delayed, looped, slow-motion and split-screen playback, a search facility, analysis of timing and angles, and importexport of video clips.
The version licensed to Dundee schools includes a feature known as tagging, which allows team sports, such as football, rugby and hockey to be recorded, so that individual players' performances, as well as team plays and tactics, can be analysed, assessed and ultimately improved.
When backed up by a teacher's informed comments, the visual feedback and analysis can lead to speedy progress, says Mr Nicoll.
"The kids can burn video clips of themselves on to a CD, then send them by email and analyse them later in the classroom."
As well as studying their own performance and gaining evidence of improvement over time, a student can compare his or her technique - both visually and by detailed analysis of timing and angles - with that of model performers. "You could play Tiger Woods's golf swing side by side with one of theirs, for instance, so they can see the differences and the areas they need to work on."
Barry Miller, the head of PE at Menzieshill High, admits he is still learning how best to integrate all the features with lessons. "It has a lot of potential," he says, at Higher and Standard grade and further down the school, not so much for detailed analysis but as a teaching and motivational tool.
"Today is the first time this class has used the package. The plan is to train them to use it themselves, so they can work together, recording and analysing their own efforts."
The cycle of analysis is common to all the elements of Higher PE, explains Mr Miller. A key component of this is gathering information about performance through feedback.
"Previously the external part of that feedback was about watching a video over and over, looking at certain parts in detail or playing it in slow motion. That was it. Now the kids have so much more to talk about. I can see it improving their performance in exams as well as on the field."
Fourth year pupil David Burns, having just watched himself in action for the first time - "apart from in front of a mirror" - is impressed. "You can easily see what it is you're doing wrong.
"I'm really looking forward to being able to use this ourselves."
Experience in the United States and English schools has shown that younger children - the younger the better - respond very well to visual feedback on themselves, says Mr Taylor.
"Kids love to see world class performers doing fancy stuff.
"I remember teaching free kicks. You would show Beckham doing it first, then they would try it for a while and eventually one child would get it.
"Suddenly you'd have this very powerful image for teaching, because now they are watching someone just like them, and they're thinking 'If he can do it, so can I'.
"This software lets us capture that magic moment when a youngster does really well. At one time they might not have been sure how they did it. So they couldn't build on it and neither could the rest of the class. Now they can."
www.dartfish.co.ukKevin Taylor, tel 0131 557 2355, email firstname.lastname@example.org