(Extending your) life's a treadmill

03/09/2008

People who walk on a treadmill even years after stroke damage can significantly improve their health and mobility, according to research spearheaded at the Johns Hopkins University School of Medicine. The results suggest that patients' brains may retain the capacity to 'rewire' through a treadmill exercise program months - or even years - after conventional physical therapy has ended.

 

Dr. Daniel Hanley, a professor of neurology at the Johns Hopkins University School of Medicine, said: "This is great news for stroke survivors, because results clearly demonstrate that long-term stroke damage is not immutable, and that with exercise it's never too late for the brain and body to recover."

 

A number of scientists at different institutions have developed treadmill therapy for stroke patients over the past decade, and for this latest research 71 patients were recruited who had had a stroke at least six months earlier, with an average time lapse of nearly four years. At the study's onset, half could walk without assistance, while the rest used a cane, a walker or a wheelchair.

 

They were separated into two random groups, regardless of disability, and tested for mobility and aerobic capacity. Thirty-two patients drawn equally from both groups underwent functional magnetic resonance imaging (MRI) to assess brain activity linked to moving their legs in a walking motion.

 

One group then participated in an exercise program that principally involved walking on a treadmill three times a week for up to 40 minutes, assisted by a supporting sling and tether if needed. 

Physical therapists assigned to each subject increased the intensity of the workouts over time by increasing the treadmills' speed and incline, although the workouts never taxed the patients beyond a moderate level.

 

With the second group of patients, therapists assisted the patients in performing stretching exercises for the same period of time.

 

After six months, the patients were again tested for walking speed, and the same group who had undergone MRI was rescanned. Walking speed for the treadmill group increased 51% compared to about 11% faster for those in the stretching group. And ground walking speed among the treadmill exercisers increased 19%, compared to about 8% for the stretchers. The treadmill exercisers also were significantly more fit when the study was finished.

 

The researchers also analysed the brain scans and found markedly increased metabolic activity in brainstem areas associated with walking among all the treadmill exercisers. But brain scans of patients in the stretching group showed no such changes.