retropulsion

1. (medicine) A tendency to step or walk backwards involuntarily, especially as a symptom of parkinsonism.Examples: "Retropulsion most often occurs when you are trying to reach for something higher than sholder level."; "For patients prone to retropulsion, wearing shoes with high heels may diminish or prevent the backward stepping."; "Pretreating rats with α-methyl-ρ-tyrosine (30 mg/kg i.p. at -4 h) to interrupt the synthesis of catecholamines antagonized pivoting and retropulsion induced by levallorphan (50 mg/kg i.p.) (WRAY 1973) but, surprisingly, not lateral head movements and pivoting elicited by cyclazocine (3 mg/kg s.c.) (BUCKETT and SHAW 1975)."countableuncountable

2. (medicine) The pushing or forcing of something to move backwards or inwards.Examples: "Retropulsion of the eye slackens the rectus muscle and, if forced ductions improve with retropulsion, then the restriction is secondary to a tight rectus muscle."; "Spinal CT or MRI reveals violation of the posterior cortex of the vertebral bodies (burst fracture) with retropulsion of bone into the spinal canal."; "The goal of retropulsion is to expand the diameter of the urethra with fluid to suspend the obstructing substance in a fluid column that will carry it back into the bladder."countableuncountable

3. (medicine, obsolete) Transfer of a disease from an external source to an internal organ.Examples: "From this account, it will also be evident, that there can be no danger from the retropulsion, or rather the retiring of prickly heat, except what may arise from the cause that checked perspiration. Many absurd notions have been entertained on this subject, which have really proved prejudicial to health. It hs been very generally supposed, that the matter of prickly heat was highly injurious, and therefore, that the retiring of it into the body was extremely dangerous."; "The arthritic blepharoblenorrhœa and ophthalmoblenorrhœa appear only as a real metastasis of gout, having always followed its retropulsion in the great toe, from the application of cold moisture."; "And hence dry asthma, like the preceding, as thus diversified by its occasional causes, may be contemplated under the following varieties: ... From retropulsion of some acrid humour from the surface of the body."countableobsoleteuncountable