retropulsion
/ˌrɛtrə(ʊ)ˈpʌlʃn/Medicine
noun
1The action of pushing something backwards; an instance of this.
2A tendency to walk backwards involuntarily or in an uncontrolled manner, occurring in parkinsonism.
Origin
Mid 18th century (in an earlier sense). From retro- + pulsion, in sense 1 after post-classical Latin retropulsio, in sense 2 after French rétropulsion.