And Yet It Moves: What We Currently Know about Phantom Arm Movements

Abstract

What is left over if I subtract the fact that my arm goes up from the fact that I raise my arm? Neurological evidence invites the provocative hypothesis that what is left over is a phantom arm movement—a movement of an arm that has been amputated. After arm/hand amputation, many amputees report that they can generate voluntary movements of the phantom limb; that is, they can move the arm that was amputated. But what is it like to move an arm/hand that is not there? Here, we review what is currently known about phantom limb movements at three descriptive levels: the kinematic level, the muscle level, and the cortical level. We conclude that phantom arm movements are best conceptualized as the real movements of a dematerialized hand.

The homeostatic homunculus: rethinking deprivation-triggered reorganisation

“…This research draws on the lingering sensations arising from the missing limb that affect about 90% of adult upper-limb amputees [15]. By taking advantage of amputees' ability to voluntarily move their phantom hand, the signals elicited both centrally and at the periphery were found to differ from those produced by movement imagery [16]. This experimental approach, combined with advanced fMRI methods, uncovered SI finger maps of the missing hand, even decades after amputation [17].…”

Making sense of phantom limb pain

“…A form of non-painful phantom sensations that have been linked with PLP relates to kinetic sensations, which includes the ability to voluntarily move the phantom limb and, in some cases, non-voluntary phantom movements (for a review see63). There is some evidence supporting a relationship between the ability to volitionally move the phantom limb and lower PLP intensity 64 65.…”