Reducing knee joint load during gait in patients after tibial plateau fracture remains a long-term challenge, and effective interventions have not yet been established. This case report involved a 52-year-old female patient, three months after surgery for a tibial plateau fracture accompanied by an anterior cruciate ligament (ACL) avulsion injury. A self-exercise given by the therapist aimed at strengthening both knee extensor and hip abductor muscles was implemented to improve knee joint load during gait. The intervention followed a withdrawal and reversal design (BAB) over two 6-week phases, with weekly strength measurements and assessments of knee flexion angle, performance tests, and three-dimensional gait analysis conducted at the end of each phase. During the intervention period, an increase in knee flexion moment and a decrease in knee adduction moment were observed, indicating improvements in knee joint load. These results underscore the importance of combined knee extensor and hip abductor strengthening exercises.