Twenty-nine studies (n=315, range one to 45) were included: seven randomised controlled trials, three controlled non-randomised trials, eight prospective cohort studies, three case series and eight case reports. Strength of evidence of about half of the studies was rated as level IV (using the Sackett Level of Evidence). Quality of evidence of about half of the studies was rated 2 using the PEDro scale (range 2 to 6).
Cerebral palsy and other central nervous system disorders (17 studies): One level 3 non-randomised controlled study found a significant effect on self-selected gait speed compared with control and one level 2 RCT. Some positive outcomes were found in the other studies (evidence level 4 or 5), but overall results were inconsistent.
Down syndrome (six studies): Treadmill training was associated with positive effects on independent walking and a number of quantitative and qualitative aspects of gait performance. There was some evidence to suggest that higher intensity training protocols may have been more effective than less intense protocols. Most studies were RCTs. Most studies used same samples or subsamples.
Spinal cord injuries in children and young adults: Treadmill training was associated with positive outcomes in most of the results and a number showed large and clinically significant changes (such as progression from no ability to step to walking independently with an assistive device by end of training).
Adverse effects: Few studies reported data on adverse effects; none reported occurrence of any episodes that were anticipated and monitored.