Treadmill training can improve the impaired walking associated with Parkinson's disease, researchers said.
The technique leads to improvements in gait speed, stride length, and walking distance, but not gait cadence, according to Jan Mehrholz, PhD, of the Klinik Bavaria in Kreischa, Germany, and colleagues.
However, it remains unclear how long such improvements last, the researchers noted in a Cochrane Systematic Review.
Treadmill training has emerged recently as a "promising investigational therapy" aimed at patients with weakness on one side of the body and impaired gait, Mehrholz and colleagues wrote in their review.
To evaluate what's known about the subject, the researchers searched the literature and found eight randomized, controlled studies with a total of 203 participants.
On average, patients were 61, with an average duration of disease in the studies ranging from one to eight years.
When the studies were analyzed, the researchers found:
•Seven studies -- with153 participants all told -- found that treadmill training improved gait speed.
•Five studies, with a total of 95 participants, looked at stride length and found that treadmill training was beneficial.
•Two studies, with 41 participants, found that treadmill training improved walking distance.
•Finally, four studies (with 78 participants) found no significant mean difference in cadence.
The treadmill training was acceptable to patients, the researchers said, in that it did not increase the risk of patients dropping out of studies. Adverse events were not reported.
The researchers noted that the study protocols varied markedly.
The treadmill training lasted from one 30-minute session to eight weeks, although most studies used a four-, six- or eight-week period. Frequency varied from a single session to four times a week, the researchers said.
The type of treadmill training also varied, with some investigators using body-weight supported treadmill training and others a speed-dependent approach.
Primary outcomes also differed, Mehrholz and colleagues said.
Because of those variations, they said, there is "still a need for well-designed large-scale studies" to look at the risk and benefits of treadmill training for Parkinson's patients.
Specifically, they said, those studies should address open questions about how long the effect lasts and what should be the frequency and duration of training.