The purpose of this study is to compare movement variations before and after the loaded training, with kinematics, kinetics, and electromyography, in children with spastic diplegia and to further discuss mechanisms of the loaded training.

Subjects: This study will recruit twenty children who are aged between 5 and 12 years, with spastic diplegia, and without having major surgeries or botulinum toxin injection on lower extremities during the past 6 months prior to participate in this study.

Methods: The Vicon 250 motion analysis system, 3 AMTI force platforms and the EMG recording system will be used to collect data of sit-to-stand (STS) movements. Baseline, pre- and post-training evaluations will be carried out. The duration of the baseline and pre-training evaluations is 2 months. The training period will take about 6 weeks. Each evaluation will take two separate days to accomplish. On the first day, the STS1RM of individual children was determined. On the second day, kinematic and kinetic data of STS movements in natural and loaded (applying load of 50% STS1RM during STS movements) conditions were collected. Data of smoothness, maximal extension moment and around hip and knee joints, onset time of lower extremity muscles will then be calculated. Results of each evaluation will be used for further comparison.

Inclusion Criteria:

• Diagnosed as spastic diplegia
• Aged between 5 and 12 years
• Able to perform the STS movements without assistance
• Able to cooperate and understand commands given

Exclusion Criteria:

• Severe musculoskeletal deformity or pain on lower extremities
• Botulism injection in the past 3 months or major operations in the preceding 6 months on lower extremities
• Uncontrolled epilepsy
• Major sensory deficits, such as blindness or deafness