A Physical Therapy Program Targeting Lower Extremity Selective Motor Control in Children With Spastic Cerebral Palsy

The goal of this intervention study is to learn whether a physical therapy exercise camp called will improve leg movement (motor control) and functional ability in children with spastic CP who are between 5 and 18 years. The main questions the study aims to answer are: * Does the ability to move the knee at high velocities improve? * Does function such as walking, running, hopping, climbing stairs improve? * Will the brain tracts that control movement change? * Will children who have better independent control of joint motion improve more? All participants will: * Attend 15 sessions of an exercise camp for 3 hours per day * Perform a home exercise program after the camp ends Measurements: * Lower extremity selective motor control * Knee muscle strength at high speeds using an exercise machine * Gross motor function * Gait analysis (walking patterns) * Parent's perception of their child's ability and their satisfaction with that ability * Change in brain motor tracts using a scanner (MRI) for participants that meet the inclusion criteria for MRI MRI measurements will be taken twice (before and immediately after the treatment). All other measurements and will be taken 3 times (before, immediately after the treatment and approximately 4 months after the treatment).