Evaluation of the pull test technique in assessing postural instability in Parkinson's disease.

Variability in pull test (PT) performance can lead to inadequate evaluation of postural instability in patients with Parkinson's disease (PD). Assessing 66 PTs by 25 examiners, at least two of four raters agreed that specific items were performed incorrectly for stance in 27.3%, for strength and briskness of the pull in 84.9%, for examiner's response in 36.4%, and for technique issues in 9.1%. Examiners were consistent in their errors, and only 9% of examinations were error-free.