The demand for rehabilitation services has been increasing over the years due to the aging population and the increase of people with disabilities. This results in an overload of health professionals who need to monitor the treatment of individuals, especially those with mobility impairments. The rehabilitation process can be painful and frustrating to patients, resulting in high dropout rates. An alternative to overcome this issue is the use of emerging technologies, such as mixed reality and robotic assistive devices. In this context, our paper presents a pilot study on the integration between a smart walker device and 3D motion capture systems to enhance the immersion of a mixed reality rehabilitation scenario. Five volunteers were recruited to use the system in a 6-min walk test. The results show that it was able to explore different behaviors in users within the 6 min, in the velocity and the forward forces discharged in the smart walker, with a statistically significant difference (p < 0.05). In future work, we aim to stream all data obtained from the system to a cloud platform, providing a tool for telerehabilitation.