This case demonstrates the effectiveness of a rehabilitation product and protocol that incorporates manual therapy and unstable surface training. The purpose of this case study was to evaluate the effect of a four-week unstable training protocol using PRIMFIT product in conjunction with manual physical therapy on walking gait in a 17-year old, with grade 3 ankle sprain and multiple ligament tears. A PRIMFIT protocol was designed and performed biweekly under supervision of a physical therapist and also biweekly by the patient independently. Patient's walking gait was tested once a week using an OPTOGAIT System. The patient demonstrated significant clinical and statistical improvements in all gait and time parameters measured by OPTOGAIT system, as well as increased ankle mobility, decreased swelling and markedly decreased pain. For this patient, a combination of manual therapy techniques, PRIMFIT product and rehabilitation exercises were able to significantly improve and normalize walking gait, in addition to eliminating swelling and pain. However, further research is needed with additional cases, especially those with similar or other injuries to develop the efficacy of the PRIMFIT product and protocol.