Impaired Economy of Gait and Decreased Six-Minute Walk Distance in Parkinson's Disease

Figure 1

Submaximal VO₂ measured at self-selected walking speed during the last 40 seconds of the first 2-minute stage of treadmill test versus walking speed in mph. Diamonds show measured values, where solid line shows expected value (VO₂ mL/kg/min predicted = 0.1 × 26.8 speed in mph + 3.5). The vast majority of subjects had measured values higher than the predicted values indicative of poor economy of gait.