Eileen G. Fowler, Loretta M. Knutson, Sharon K. DeMuth, Kara L. Siebert, Victoria D. Simms, Mia H. Sugi, Richard B. Souza, Roksana Karim, Stanley P. Azen;
for the Physical Therapy Clinical Research Network (PTClinResNet)
Background: Effective interventions to improve and maintain strength (force generating capacity) and endurance are needed for children with cerebral palsy (CP).
Objective: This study was performed to examine the effects of a stationary cycling intervention on muscle strength, locomotor endurance, preferred walking speed, and gross motor function in children with spastic diplegic CP.
Design: This was a phase I randomized controlled trial with single blinding.
Setting: The interventions were performed in community-based outpatient physical therapy clinics. Outcome assessments were performed in university laboratories.
Participants: Sixty-two ambulatory children aged 7 to 18 years with spastic diplegic CP and Gross Motor Function Classification System levels I to III participated in this study.
Intervention and Measurements: Participants were randomly assigned to cycling or control (no-intervention) groups. Thirty intervention sessions occurred over 12 weeks. Primary outcomes were peak knee extensor and flexor moments, the 600-Yard Walk-Run Test, the Thirty-Second Walk Test, and the Gross Motor Function Measure sections D and E (GMFM-66).
Results: Significant baseline-postintervention improvements were found for the 600-Yard Walk-Run Test, the GMFM-66, peak knee extensor moments at 120°/s, and peak knee flexor moments at 30°/s for the cycling group. Improved peak knee flexor moments at 120°/s were found for the control group only, although not all participants could complete this speed of testing. Significant differences between the cycling and control groups based on change scores were not found for any outcomes. Limitations. Heterogeneity of the patient population and intrasubject variability were limitations of the study.
Conclusions: Significant improvements in locomotor endurance, gross motor function, and some measures of strength were found for the cycling group but not the control group, providing preliminary support for this intervention. As statistical differences were not found in baseline-postintervention change scores between the 2 groups; the results did not demonstrate that stationary cycling was more effective than no intervention. The results of this phase I study provide guidance for future research.