Presented is the design, implementation, and initial gait testing of a lightweight, compliant robotic device for ankle rehabilitation. Many patients with neuromuscular disorders suffer deficits in sensorimotor control of the ankle joint, leading to an abnormal walking pattern. Robotic devices have been used to assist ankle rehabilitation. However, these devices are usually heavy and rigid, which can deviate a natural gait pattern. To address these issues, our team has developed a light weight, compliant ankle robotic device actuated by artificial pneumatic muscles. A total of 3 healthy subjects were recruited to test whether the mechanical structure of the device deviates gait. We used a 3-dimensional (3D) motion analysis system to record and analyze subjects' ankle kinematics during gait while walking barefoot and while wearing the device unpowered. The preliminary results suggest that the device caused some, but minimal changes in ankle kinematics during gait. The changes were mainly caused by the device's rigid footplate, used to support the foot and connect to the pneumatic muscles. The preliminary results will be used for future improvement of the device.