HERSHEY, Pa., Dec. 10 (UPI) -- U.S. medical researchers say they've determined asymmetrical arm swings while walking might be an early sign of Parkinson's disease.
Scientists at Penn State Hershey College of Medicine and the University of North Carolina said Parkinson's disease is an age-related disorder involving loss of certain types of brain cells and marked by impaired movement and slow speech.
"The disease is currently diagnosed by tremors at rest and stiffness in the body and limbs," said Penn State Associate Professor Xuemei Huang. "But by the time we diagnose the disease, about 50- to 80 percent of the critical cells called dopamine neurons are already dead."
Huang and her colleagues say they've confirmed the hypothesis that people with Parkinson's display an asymmetrical arm swing. In other words, one arm swings much less than the other as a person walks.
"We believe this is the first demonstration that asymmetrical arm swings may be a very early sign of the disease," said Huang, who noted that while slightly irregular arm swing occurs in people without Parkinson's, the asymmetry is significantly larger in those suffering from the disease.
The research that included University of North Carolina Assistant Professor Michael Lewek and researchers Roxanne Poole, Julia Johnson and Omar Halawa appears in the journal Gait and Posture.