Children with CP may experience spasticity and muscle weakness. All impaired muscle functions limit the mobilization ability in a child with CP. Strength training for these children is expected to improve their mobility. Periodization is aimed to stimulate physiological and psychological adaptation (preparatory phase), to enhance the performance capabilities (competitive phase), followed by a transition phase that aims to relax and prepare for the next phase. The purpose of this study is to investigate effectiveness of a functional strengthening program with periodization for children with CP on walking ability and energy expenditure.

Methods: Twenty-two children (aged: 7-14y.o.) with spastic diplegia CP and level I-III Gross Motor Function Classification System were evenly stratified and randomly allocated into either the experimental or control group. The experimental group underwent home-based loaded-sit-to- stand strengthening exercise (3 times/week, 7 weeks). The outcome measures are walking ability (stride length, cadence, and walking speed), and Physiological Cost Index (PCI), conducted at the beginning and end of the 7-week study.

Results: After 7-week exercise, it showed changes on stride length (13,99% vs -2,46%; p:0,006), cadence (12,27% vs -7,92%; p:0,007), walking speed (12,65% vs -0,64%; p:0,028), and PCI (24,23% vs -25,66%; p<0,001) between experimental group and control group.

Conclusions: After the loaded sit-to-stand exercise, children with spastic diplegia improved their walking ability (stride length, cadence, and walking speed), and decreased energy expenditure.