12 adults with spastic CP will complete 6 baseline sessions and 24 down conditioning sessions held 3 times/week. All clinical and physiological assessments collected at baseline will be reassessed after study completion, and follow ups after 2 weeks, 1 month and 3 months. The soleus H reflex (electric analogue of the stretch reflex) will be elicited in all sessions. In each session, participants will complete 20 baseline trials and 225 down conditioning trials to decrease the magnitude of the H-Reflex.