The tears streaming down Jade Johnson's face were not of pain - but of frustration. More than eight million viewers watched the 29-year-old athlete pressing a bag of frozen peas to her heavily bandaged knee just before she was about to dance the tango in the BBC's Strictly Come Dancing, but she never took to the floor. Disaster had struck only hours before during a dress rehearsal.
'I wasn't just crying because it hurt, although it was very painful,' says Jade. 'It was more out of the anger I felt at not being able to perform and knowing that the injury might mean I was out of the competition for good.'
Jade, whose day job is as a world-class long-jumper, had suffered a common and excruciating knee injury experienced by thousands across the UK each year. She had been forced to sit out the competition that night after suffering a torn ligament.
In the week of the accident, Jade, who was paired with professional dancer Ian Waite, was to end their dramatic routine with a spectacular drop to the floor. After she did this in the dress rehearsal and was getting to her feet, an unexpected act of chivalry by Ian ended in disaster.
'I had finished sitting with my legs out to the side at a right angle,' recalls Jade. 'All week while we were rehearsing, Ian had just left me to get up off the floor by myself. It looked rather ungraceful.
'But then, during the dress run he suddenly decided, without telling me, that he would help me stand up. I was pushing one way as Ian was pulling the other and my left knee twisted. I heard a pop and felt an instant stab of pain. I just burst into tears.'
Jade was devastated that the show would be starting within a couple of hours and remembers that putting any weight at all on her leg was agonising.
'If you can imagine the worst toothache and headache you have ever had, joined together and multiplied by ten, that is how bad it was. Ian was shocked - he was incredibly apologetic, but it wasn't his fault.'
After the BBC doctor had examined her, Jade called her own physiotherapist, Kevin Lidlow, who promptly sent her to hospital. An MRI scan revealed Jade had sustained a parital tear to the medial collateral ligament (MCL), which runs from the end of the femur to the top of the tibia on the inside of the joint.
Lidlow explains: 'Ligaments are bunches of fibres like rope, which provide stability to the knee joint. When they are overstretched, some or all of the fibres can break.
'Jade did this simply by getting up off the floor at an odd angle, but you can easily do the same getting out of a car or just turning quickly. Alongside the pain, the joint becomes unstable, so walking is made difficult.'
There are 153,000 hospital visits each year due to knee and lower-leg injuries, according to Department of Health statistics - although specific figures for MCL damage are not available. Injury to cartilage - the substance that lines the joint, allowing smooth movement - is notoriously difficult to treat.
It does not heal and so complex surgery is often required. But in most cases ligament damage simply requires a period of rest - ranging from two weeks to three months depending on the injury.
'All soft-tissue damage will heal given time, but without the right medical supervision - physiotherapy and either bandages or a brace to give support - this can take a long time, and lead to excessive amounts of scar tissue forming, which can weaken the ligament in the long term,' says Lidlow.
Jade, who as a professional athlete admits she is fiercely competitive, was not prepared to limp away from the contest.
'When I got the scan results my heart sank,' she says. 'The doctors tightly bandaged my knee to help keep down the swelling and said I would have to stay off my feet for a week. But Kevin said he could have me dancing by Friday.'
Frustratingly for both Jade and Ian, the couple had staged a comeback since ending up in the Dance Off two weeks before.
'My main concern was for Jade,' says Ian. 'I know just how painful these injuries can be and how long they can take to heal. They are not uncommon in dancers.
'Obviously I felt terrible, but more than anything I was disappointed for her because she could have gone all the way to the final.'
Jade underwent a combination of intensive physiotherapy - including muscle-strengthening exercises and friction massage, aimed at reducing scar-tissue formation - and a new treatment, Hilotherapy. Iced compresses are, typically, applied to injured joints in order to bring down swelling and aid healing.
However, such aggressive cold treatments when used in the long term can damage the skin (extreme cold can burn in the same way as extreme heat). Ice temperature is also hard to regulate. 'I usually keep two bags of peas in the freezer so I can rotate them,' says Jade.
Cosmetic surgeons already use Hilotherapy machines to reduce postoperative swelling. Manufactured by German company Hilotherm, they work by circulating cool water through adjustable cuffs that fit most body parts. The temperature can be controlled and kept constant, and the cuffs can be worn for up to eight hours a day.
'There's nothing new about cold therapy - we've known for a long time that low temperatures aid healing,' says Lidlow. 'The good thing about this therapy is that it creates an optimum low temperature without the potential damage ice can cause.'
Currently available only at private clinics, Hilotherapy treatment costs between £30 and £40 per hour-long session, and trials on NHS patients are under way at Ulster Hospital, Belfast. Preliminary results show face and mouth-surgery patients who are given the treatment have their hospital stays halved, which doctors say is 'remarkable'.
Jade was lent a machine by the manufacturers to use at home. 'On the Monday, when I took the bandages off, my knee was heavily bruised and swollen but gradually over the week the pain and inflammation went down,' she says.
'I divided my time between sessions with Kevin and the BBC physiotherapist. At home I would sit with the cuff strapped to my knee.
'Ice packs can burn a bit but this was comfortable. It really helped and by Friday I was able to tango again. It is a dance you do with your knees bent most of the time and it's straighten-the leg that is difficult. But unfortunately, even though I was ready to perform live again, it wasn't good enough for the BBC physiotherapist.'
Jade was told by the show's producers and her management that she would have to quit the series - which seems to have been cursed by injury and illness - despite her own insistence she was fit.
'I had no choice in the matter,' she says bitterly. 'I had been working hard with my physiotherapist all week to get back into shape and knew I could dance, but the BBC doctor said he didn't feel comfortable giving me the all-clear.
'My management were worried that further dancing could compound the injury and jeopardise my career.
'I do have to be careful but I have injured myself enough times while training that I know my body, and I knew I wasn't going to be at risk.
'I am absolutely gutted. Ian and I had stayed in touch in the whole time and he came to my physio sessions. We're very close and he's incredibly disappointed, too.'
Jade says she does not blame Ian for her injury, but she does feel cheated by her untimely exit from the competition. 'The worst thing about it all was I felt as if I had just found my confidence,' she says.
'Finally I had really started to believe I could make the final. Now it feels as if that's been snatched away from me.'
Although Jade now has her sights on the London 2012 Olympic Games, she isn't quite ready to hang up her dancing shoes.
'I'm taking it easy but I'll be back to normal training in a week or so. I've loved dancing - it is so different from anything I've done before.
'I may be out of the running this series but I hope Strictly invite me back for the Christmas special.'