A Cochrane review included 18 trials with a total of 633 patients with Parkinson’s disease. There was no follow-up in 10 studies, and for the other trials the follow-up was from one to six months. Treadmill training improved gait speed (MD = 0.09 m/s; 95% CI 0.03 to 0.14; 17 studies, n=510), stride length (MD = 0.05 metres; 95% CI 0.01 to 0.09; 10 studies, n=333), but walking distance (MD = 48.9 metres; 95% CI -1.32 to 99.14; 10 studies, n=416) and cadence did not improve (MD = 2.16 steps/minute; 95% CI -0.13 to 4.46; 10 studies, n=336) at the end of study. Treadmill training did not increase the risk of patients dropping out from intervention (RD = -0.02; 95% CI -0.06 to 0.02; 18 studies, n=633). Adverse events were not reported in included studies.
Comment: The quality of evidence is downgraded by inconsistency (heterogeneity in patients and interventions) and indirectness (short follow-up time).