In the virtual world, there is no pain.
But virtual reality might be able to help doctors and physiotherapists treat chronic pain, one of society's most debilitating health problems.
Using commercially-available headsets and handsets, Australian company Reality Health has developed a virtual reality program it hopes will make a dramatic difference to the treatment of chronic pain, the leading cause of disability worldwide according to the Global Burden of Disease study.
A key part of the program is to do what clinicians find most difficult – convince patients that chronic pain arises in the brain, not from an unhealed injury.
Lorimer Moseley, a clinical neuroscientist and chair in physiotherapy at the University of South Australia, said this is something that's often called "pain system hypersensitivity".
"Pain protects us and promotes healing … persisting pain over-protects us and prevents recovery," Professor Moseley, who provided some paid advice to the program's developers, said.
"The pain system becomes overly protective and it actually stops you doing the very things you need to do to recover."
The virtual reality program tries to overcome this by essentially tricking the patient's brain into thinking they are moving less than they really are.
"The positive attributes of VR are that we're able to change the sensory input in the brain and by doing this we can actually change the stimulus that the brain's receiving," Nigel Cowan, the CEO of Reality Health, told the ABC.
"We can reduce the sensory input which means that the brain is less likely to want to produce pain and when we combine this with normal rehab therapy it allows patients to advance much faster than they would normally."
Reality Health asked some physiotherapists to try its virtual reality program on willing patients with the four most common areas of chronic pain: lower back, neck, shoulder and knee.
Patients put on the headset and receive some education about pain – where it comes from, how it arises and why it persists in some cases.
They then complete a series of tasks that require them to move in ways that would normally provoke their pain, but shows them moving less in the virtual world than their actual movement in real life.
"In the virtual environment we can basically trick their perception a little bit and that means they can move a lot further than they would normally," Adelaide physiotherapist Leander Pronk, who is trialling the VR program without payment, told the ABC.
The clinician then films the patient as they complete the VR exercises, so they can see the difference between their perceived and actual movements when they finish the session.
"The results were just mind-blowing for most of my clients," Mr Pronk said.
"Because they know pain is not related to tissue damage as such, and more to the brain being protective, and once they realise that pain is just a protective signal, they feel more confident to go to that limit and sometimes even beyond."
VR also applicable in 'range of mental health areas'
Former mechanic John Harris said the VR program had helped him deal with chronic back pain that has limited his movement for years.
"I was just blown away. It was something I've never experienced before," he said.
"When Leander showed me the pictures of me doing it afterwards, how far I stretched without realising was quite amazing."
The use of virtual reality in healthcare goes back more than two decades, but its previously high cost and limited availability meant there was not a lot of clinical evidence about its effectiveness.
That is now changing, as cheaper headsets and software make VR more accessible.
Professor Paul Glare, the director of the Pain Management Institute at Sydney University, who is not involved with the development of the VR module, told the ABC the technology seemed promising.
"It makes a lot of sense in neuroscience, why it would work, and it would be surprising if it didn't work in clinical trials," he said.
"It's definitely an area that's got a lot of potential and I presume that if it hasn't already been shown to be effective compared to some other treatment, I'm sure it will be."
This VR program deals with chronic pain, but its developers hope it can be used for other conditions as well.
"It's also being trialled now in a range of mental health areas with virtual reality being used in anxiety and depression," Mr Cowan said.
"It's also being used in surgical procedures and a whole range of activities."
