Question: Do strengthening interventions increase strength without increasing spasticity and improve activity, and is there any carryover after cessation in children and adolescents with cerebral palsy?
Design: Systematic review with meta-analysis of randomised trials.
Participants: Children with spastic cerebral palsy between school age and 20 years.
Intervention: Strengthening interventions that involved repetitive, strong, or effortful muscle contractions and progressed as ability changed, such as biofeedback, electrical stimulation, and progressive resistance exercise.
Outcome measures: Strength was measured as continuous measures of maximum voluntary force or torque production. Spasticity was measured as velocity-dependent resistance to passive stretch. Activity was measured as continuous measures, eg, 10-m Walk Test, or using scales eg, the Gross Motor Function Measure.
Results: Six studies were identified and five had data that could be included in a metaanalysis. Strengthening interventions had no effect on strength (SMD 0.20, 95% CI -0.17 to 0.56), no effect on walking speed (MD 0.02 m/s, 95% CI -0.13 to 0.16), and had a small statistically-significant but not clinically-worthwhile effect on Gross Motor Function Measure (MD 2%, 95% CI 0 to 4). Only one study measured spasticity but did not report the between-group analysis.
Conclusion: In children and adolescents with cerebral palsy who are walking, the current evidence suggests that strengthening interventions are neither effective nor worthwhile.