The Influence of Motor and Nonmotor Factors on Ambulatory Activity in People With Parkinson Disease.
Cielita Lopez-Lennon, Jennifer Hale, Anson Rosenfeldt and 6 others
Off-medication motor severity was weakly linked to fewer daily steps in PD, but the association lost significance when depression was added to the model.
Lightheadedness on standing was the stronger finding: those reporting it averaged 1,899 fewer steps per day.
Key findings
1Motor severity assessed in the off-medication state was significantly associated with fewer daily steps (β: −30 per point, P = 0.04), while the same scale in the on-medication state was not (β: −23, P = 0.15). The authors note the off-medication effect was modest in magnitude.
2When depression was added as a covariate, the off-medication motor severity association was attenuated to non-significance (β: −21, P = 0.159). Only 17 participants had clinically meaningful depressive symptoms, so this estimate was underpowered.
3Of 12 nonmotor symptoms tested, only lightheadedness on standing was significantly associated with fewer daily steps (β: −1,899, P = 0.006). The authors note this reduction exceeded PD-specific minimum clinically important differences of 580 to 1,590 steps per day.
Still to come
How it was doneWhat they foundWhat it means for PTs
Read the rest of this summary
You get three full summaries a month, free, and we do not ask for a card. Search, the TL;DRs and your library stay unlimited either way.
What it does not show
Cross-sectional design: all data are from a single baseline assessment, so no causal direction can be inferred for any of the associations. The off-medication motor severity effect was modest (30 fewer steps per point) and became non-significant when depression was included as a covariate, weakening the novel contribution the paper sets out to make. Only 17 participants had clinically meaningful depressive symptoms, making the depression-adjusted model underpowered and the estimate unstable. Participants were volunteers for an exercise trial, which may select for higher motivation, health literacy, and access to research facilities compared with the broader PD population. Dementia was an exclusion criterion, so findings do not extend to the full spectrum of PD-related cognitive decline. Factors known to influence physical activity in PD — self-efficacy, fear of falling, social support — were not measured and may account for meaningful variance in daily steps. No formal statistical test was conducted to directly compare the relative strength of the on- versus off-medication associations; the two models were examined separately. Nonmotor symptoms were assessed using MDS-UPDRS Part I items, which the authors acknowledge may lack the sensitivity of more comprehensive or objective tools for detecting subtle symptom differences.
Declared interests
The authors declare no conflict of interest. No funding source is named in the text provided.
The easy way to misread this
Do not read the off-medication motor severity result (P = 0.04) as a strong, independent driver of daily steps. The effect was modest — 30 fewer steps per point on the MDS-UPDRS III — and it became non-significant (P = 0.159) once depression was included in the model. The cross-sectional design also means the association cannot be read as causal: it is equally possible that people who walk less report more motor impairment, or that a shared factor drives both.
Summarised by AI from the full paper, without a clinician reviewing it. Check it against the source before it changes what you do. Read it on PubMed →