Ankle fractures, common in high-risk sports, cause significant pain and can be treated with mobilizers. This study presents the development and validation of a continuous passive motion prototype for ankle rehabilitation. Based on mechatronic design methodology, the prototype focuses on dorsiflexion and plantar flexion movements. The design includes foot support and a gliding system inspired by backhoe excavator mechanisms. Computer-aided design, material selection, and finite element analysis in Solidworks were used to conceptualize, visualize, and simulate the prototype. Safety factors of critical system components exceeded safety limits to ensure structural integrity. Digital PID control with an RST controller achieved precise angular position control, complemented by a motor speed control algorithm for fast, precise motion. The prototype, constructed with appropriate materials, accommodates different foot sizes and provides comfort and safety during therapy. Professional physical therapists and end-users (without clinical history) performed quantitative validation. The evaluation focused on physical adaptation, functional range of motion, hygiene, protocol compliance, feasibility, ergonomics, reliability, design, and perceived safety. Structured surveys indicated good acceptance, with average ratings ranging from 3.5 to 4.8. A positive perception of the surveyed population was obtained, which implicates the prototype’s feasibility in therapeutic applications. The study highlights the potential of mechatronic design in developing effective rehabilitation devices and offers a promising solution for ankle fracture recovery in sports medicine and physical therapy.