Postural instability in the anterior-posterior plane is associated with impaired postural verticality perception and fall risk in Parkinsonian syndromes

Abstract

Abstract Retropulsion is a postural behavior which seems frequent in Parkinsonian syndromes, hampering balance and functional tasks, as well as entailing an increase in the risk of falls. This study aimed to investigate different characteristics of retropulsion and their relation to functional disability, postural control and fall risk. Thirty subjects with Parkinsonian syndromes (75 ± 8 years, 13 female, 6 ± 5 years since diagnosis, median UPDRS III 33 (Q1-Q3 22–40), Hoehn and Yahr stage 3 (2–4)) were assessed with the Scale for Retropulsion (SRP), the Berg Balance Scale, the subjective postural vertical, and diagnostic scales. The number of falls within the last 12 months and fall risk was determined. Results revealed signs of retropulsion in 87% of subjects. The SRP score correlated moderately to well with functional disability and disease severity, and strongly with the Berg Balance Scale. The severity of retropulsion was further associated with a backward shifted verticality perception. The SRP significantly differed between recurrent fallers and single or non-fallers and identified subjects at risk of falling. In summary, retropulsion is very frequent in Parkinsonian syndromes. Subjects with an SRP score ≥ 3 have an impaired reference of verticality with considerable balance impairments and an increased risk of falling.