This study aimed to investigate the evidence that strengthening interventions can improve
muscle strength and activity in individuals with cerebral palsy. The search focused on
studies that employed strength training for children with cerebral palsy for which six
electronic databases were used to extract literature published from 2001 to 2012. The key
terms used in these searches were combined strength training, strengthening, weight
training, weight lifting, resistance, and cerebral palsy. The quality of each study was
assessed using the PEDro (Physiotherapy Evidence Database) scale. Thirteen randomized
controlled trial studies were selected and divided into categories according to program
type, mode, and outcome measures. The overall effect sizes of each study and types of
strengthening were large. Strengthening exercise improved muscle strength to a greater
degree, when practiced 3 times per week in 40–50 min sessions than in other categories of
session length, and greater improvement was observed in younger children than in older.
The effect size of the activities and variables related to gait, except for gait endurance, were
medium to large. The effect size of individual muscles was large, but the effect sizes for
ankle plantar flexor, hip abductor/adductor, and extensor were insignificant. Strengthening
interventions are useful for increasing muscle strength in individuals with cerebral
palsy, specifically in youth and children, and optimal exercise consisted of 40- to 50-min
sessions performed 3 times per week. Although strengthening interventions may improve
activities, including gait, more studies that are rigorous are needed to determine the
contributions to gross motor function.