A comprehensive multivariate analysis of the center of pressure during quiet standing in patients with Parkinson's disease.

The study did not test any rehabilitation intervention, so it cannot show that any treatment improves balance. It measured quiet standing only and did not directly assess falls, so the subtypes are not fall-risk categories. All participants had to stand quietly for 30 seconds without assistance, so people with more severe balance problems were excluded. Before the main results, 11 PD patients, four older adults, and two young adults were removed as outliers. The balance recording was a single 30 second sample, not repeated trials. PD patients were measured in their usual medication state, not a controlled on/off comparison. The six subtypes were created by the analysis and were not checked against follow-up, treatment response, or a separate group. The clustering method was chosen to separate groups, so the clear cluster separation may partly come from the analysis method.

The supplied article metadata lists non-U.S. government research support. The article text does not include an author conflict-of-interest declaration.

Do not treat the six sway subtypes as clinical diagnoses or fall-risk groups. The study measured quiet standing patterns and did not test rehabilitation or assess falls.