Akathisia is a common extrapyramidalside-effect of antipsychotic (aka neuroleptic[?]) drugs. It usually manifests as pacing and a total inability to sit still. If forced to sit still the person experiences extream anxiety and agitation. In bad cases the anxiety and agitation may get worse even while the person is moving. Akathisia usually responds well to drugs commonly used to control extrapyramidal side-effects.
... smaller extent by the slipping friction.
The device is covered by US patents 3,726,146 (1973) and 5,353,655 (1994) by L.A. Mishler and US patent 5,800,311 (1998) by ...