FOURTEEN YEARS in the past, Melanie Reid, a journalist, fell off a horse and broke her neck. The harm to her spinal twine left her paralysed, limiting the perform of her 4 limbs and torso—a situation often known as tetraplegia. For years her left hand was incapable of both sensation or movement. Now, nonetheless, Ms Reid can’t solely transfer that hand; she will be able to additionally, as she places it, practise the “proper to place my hair in a ponytail”.