Low to moderate relationships between gait and postural responses in Parkinson disease.

The study is a secondary cross-sectional analysis, so it can show relationships at one time point but cannot show that gait impairment causes postural instability or that treating one will improve the other. The analysis used baseline data only, so it does not report how the trial interventions changed gait or balance. All testing was done after at least 12 h off anti-Parkinson medication, so the results may not apply to people tested while taking medication. The postural response items used 3- or 5-point scales, and most participants scored in the middle, which limits how finely these measures can separate different levels of balance control. The GAITRite walkway measured steady-state walking speed and step length, but not walking kinematics or balance control, and it did not examine gait initiation. Freezing of gait was classified by self-report on the new Freezing of Gait Questionnaire, not by episodes observed in the laboratory, and the study did not analyse freezing severity or characteristics. The participants could walk 3 m independently with or without an assistive device and were Hoehn & Yahr I to IV, so findings may not extend to people with more advanced disease who cannot walk independently.

The authors declared no conflicts of interest.

Do not conclude that gait speed and step length can replace reactive balance testing. The relationships were significant but only low to moderate, and the paper states that gait parameters have not been shown to be surrogate measurements for reactive postural response.