Pov Sopheak lost his left leg in a landmine blast in 1990. Yet some nights the pain in his “left foot” is so bad he cannot sleep.

Like many amputees, he suffers from phantom pain. Now, after two decades of agony, the Cambodian is embracing an innovative technique that promises relief simply by using a mirror to trick the brain into “moving” the missing limb, allowing the pain to subside.

Sitting in a chair and holding a full-length mirror against his leg, Sopheak, 50, smiles self-consciously as some two dozen physical therapists gather around him. It is their first mirror therapy training session at the Cambodia Trust, a rehabilitation charity for amputees.

But Sopheak visibly relaxes as he follows the instructions of visiting Canadian trainer Stephen Sumner to wriggle his right toes and keep his eyes on his foot's reflected image, super-imposed on the missing one. “It’s a new sensation. It’s strange but in a good way,” the former soldier, who now works as a security guard, told AFP. “I see my leg in the mirror and I feel happy, like my mind is at ease.”

Sumner explains that the reflection of the intact limb can fool the brain into “seeing” two healthy legs, allowing it to once again send command signals to the phantom leg – signals that would previously come back distressed because the limb was missing.

“Looking in the mirror, the brain suddenly enables you to move your phantom foot and do everything the real foot is doing,” said Sumner, 51, who lost his left leg in a hit-and-run motorbike accident eight years ago.

“The brain just wants to be tricked. It’s dying for release.”