Background: In this study, a new biofeedback system for balance and gait rehabilitation (Gamepad) was developed. The system, based on wearable inertial sensors, provides users with real-time visual and acoustic feedback about their movement during functional tasks. Gamepad was applied on subjects with Parkinson's disease (PD) in a pilot randomized controlled trial to investigate its feasibility and efficacy versus conventional physiotherapy. The investigators hypothesized that Gamepad system can be easily applied in clinical settings and that biofeedback training with Gamepad provides larger improvements of balance and gait in PD subjects, respect to conventional physiotherapy.