Subtle changes in walking could be early Parkinson’s sign
Slower turns, wider arcs may predict risk, long-term study finds
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- Subtle walking changes, like slower, wider turns, may signal Parkinson's.
- Wearable sensors can detect these changes, offering a window for early intervention.
- Early identification is crucial for future treatments to slow disease progression.
People who develop Parkinson’s disease begin turning more slowly while walking — often using wider turning arcs — nearly a decade before diagnosis, according to a long-term study involving wearable movement sensors.
“This research opens a vital window for early intervention,” Brook Galna, an associate professor from Murdoch University and a study author, said in a university press release. “By detecting changes in turning speed through wearable sensors, in combination with other early signs of Parkinson’s, we can identify individuals at risk long before symptoms become clinically apparent.”
The study, “Turning Slowly Predicts Future Diagnosis of Parkinson’s Disease: A Decade-Long Longitudinal Analysis,” was published in Annals of Neurology by a team of researchers from institutions in Germany and Australia.
Parkinson’s disease is caused by the loss of dopaminergic neurons, the nerve cells that produce dopamine, a signaling molecule involved in motor control. Symptoms develop gradually, with subtle motor changes emerging years before hallmark symptoms, such as bradykinesia (slowed movement), rigidity, or tremor, that lead to a Parkinson’s diagnosis.
“Detecting individuals in this early stage is of considerable importance, because it represents the window during which neuroprotective treatments should ideally be administered once available,” the researchers wrote.
Subtle movement changes may predict risk
A range of nonmotor symptoms, including constipation and speech difficulties, has been linked to this presymptomatic stage. More recently, researchers have begun to identify subtle changes in everyday movement that may also precede diagnosis.
Turning is a particularly demanding part of walking, requiring continuous coordination, balance, and rapid adjustments in body position. Difficulties with turning are common in people with Parkinson’s and can interfere with daily activities, prompting researchers to explore whether turning performance could help predict pre-diagnostic disease onset.
The scientists tracked turning movements in 1,051 participants from an observational study who were followed across five visits over 10 years, from 2013 to 2023. A small sensor on the lower back measured turning speed, duration, and angle as they walked for one minute along a 20-meter hallway. After exclusions, 933 participants, aged 51 to 85, were included in the final analysis.
“Wearable digital devices for [walking] analysis have shown promise over the past [two] decades,” the researchers wrote. “These devices offer objective, granular quantification of measures that are difficult to assess solely through clinical observation.”
Of the 924 participants included in the survival analysis, 23 were diagnosed with Parkinson’s during the observation period, an average of 5.3 years after their first turning assessment. Those diagnosed with Parkinson’s were, on average, 5.1 years older at the study’s start than those who did not, and most (87%) were men.
People who later developed Parkinson’s consistently turned more slowly while walking and tended to use wider turning arcs than those who did not develop the disease. Differences were most pronounced when peak angular speed was examined.
“The deterioration of peak angular velocity might be a sign of deterioration either in general speed of motion or in balance and postural stability,” the team wrote, noting that both domains are often affected in Parkinson’s disease.
“A decline in postural stability may subconsciously “incentivize” patients to turn slower and adopt a safer route using a larger arc,” they added.
Older age at baseline and male sex were independently associated with a higher risk of Parkinson’s. When turning measures were added to the analysis, slower peak angular speed (the rate at which someone turns at their fastest point) was the only turning measure linked to a significantly higher risk of future Parkinson’s diagnosis.
Using a machine-learning model that incorporated age, sex, and peak angular speed, researchers correctly identified about 60% of participants who later developed Parkinson’s and 80.5% of those who did not, with a predictive accuracy of 80.5%.
Based on longitudinal analysis, turning speed in participants who later developed Parkinson’s began to diverge from that of unaffected participants approximately 8.8 years before diagnosis.
The results suggest that “turning measures may aid in predicting the clinical [Parkinson’s disease] diagnosis and enhance a panel of prediagnostic markers for identifying high-risk individuals,” the researchers wrote, adding that the approach used in the study is “practical for large-scale screening.”
“Earlier detection of people at risk of developing Parkinson’s will speed the discovery and testing of neuroprotective treatments designed to slow disease progression and keep people living independently for longer,” Galna said.
