Changes in the coordination of step length and leg movement put people with Parkinson’s disease at risk of falls. Measuring these changes can serve as an important tool in Parkinson’s gait therapy and falls prevention, according to physical therapists.
“Parkinson’s patients are less constant in positioning their feet while walking, and gait timing tends to be unstable as a result,” explained study lead and movement science specialist Fabio Augusto Barbieri, Ph.D., of São Paulo State University in Bauru, Brazil. “Their speed rises and falls as they walk, and step length varies along with foot placement.”
Overall, these patients tend to experience falls three times more often on average than their same-age peers without the disease, Barbieri said. Measuring step-length synergy, which can involve the combined operation of legs and placement of the feet, may reveal where changes need to be made, he added.
A tailored measurement method allowed Barbieri and his colleagues to zero in on the locomotor (or musculoskeletal) system and help patients adapt movement by teaching them to combine factors such as speed and foot position while crossing an obstacle, he explained.
The study included 13 Parkinson’s disease patients and 11 age-matched controls. Participants were asked to walk up to and step over a 15 cm-high obstacle 15 times. Step length was stabilized in the Parkinson’s patients as well as in the controls.
The researchers found that the Parkinson’s patients had lower foot placement variance than did the controls when approaching and crossing an obstacle. And their step-length synergy during the crossing was weaker — or 53% lower — than it was in the controls, the authors reported.
Most members of the Parkinson’s cohort were in early stages of the disease, an ideal time to practice good stepping behaviors for future use, the authors noted.
“There are patients in our exercise group who fall three or four times a week,” Barbieri said. “It’s important to understand how these patients’ gait and locomotion adapt while crossing obstacles so that we can improve step-length synergy.”
The measurement approach “enables us to refine the exercise protocol, improve locomotion, and try to reduce fall frequency,” he concluded. “Improving synergy in Parkinson’s patients while they are walking can make a significant difference to their quality of life.”
A recent, related study found that older adults have a step length synergy index that is 38% lower than young adults. “This decline may be associated with aging-related functional deficits and tripping-related falls,” the authors theorized.