Effects of aerobic treadmill training on gait velocity, cadence, and gait symmetry in chronic hemiparetic stroke: a preliminary report.

It is widely assumed that only limited improvement in functional mobility is possible beyond the subacute period following ischemic stroke. Contrary to this notion, we studied "neurologically plateaued" stroke patients with chronic hemiparesis to assess whether a "task-oriented" treadmill-training regimen would improve walking speed, cadence, and gait cycle symmetry on a modified "Get-Up and Go" task. Five male patients with a mean age of 60.4 +/- 2.7 years (mean +/- S.D.) status post ischemic stroke (> 6 months prior) participated in this nonrandomized low-intensity treadmill exercise pilot study three times/week for 3 months. All patients had mild to moderate gait asymmetries due to residual hemiparesis. Patients were videotaped before and after 3 months of treadmill aerobic exercise (AEX) while performing a functional task consisting of arising from a chair, walking 3.1 m without an assistive device as fast as safely possible, and returning to sit. Gait events were timed using a 2-D Peak Motus video analysis system. After 3 months AEX training, times for the overall "get-up and return-to-sit" (GURS) task and the "straight-away walk" (SAW) segment decreased from 8.2 +/- 1.4 sec to 6.5 +/- 0.8 sec (mean +/- SEM) (p < 0.05), and from 3.7 +/- 1 sec to 2.8 +/- 0.7 sec (p < 0.05), respectively. These data represent improvements of 21% and 24% for the GURS and SAW segments, respectively. Mean velocity increased from 0.9 +/- 0.2 to 1.2 +/- 0.21 m/sec, a 33% improvement (p < 0.01). Mean cadence (steps/min) increased from 89 +/- 9 to 97 +/- 8, a 9% increase (p < 0.05). Mean stance and swing duration diminished for both paretic (P) and nonparetic (NP) limbs, and the intralimb stance/swing ratio values moved toward normal for both the paretic and nonparetic limbs. However, these latter changes reached significance only for the P limb. Interlimb stance symmetry was unchanged. The more impaired subjects experienced the greatest gains in gait velocity and temporal measures. Collectively, these findings indicate that treadmill exercise improves functional overground mobility in individuals with chronic, stable hemiparesis.