Reconstruction of the lower extremities is difficult due to a lack of skin laxity and muscular tissues. Here, we present a case of lower extremity reconstruction via the anterior tibial artery perforator based segmental muscle island flap. Our patient was a 75-year-old male with a chronic ulcerative wound on the right lower leg from an old car accident. A 5.0×0.5 cm size ulcerative wound with tibial bone exposure was noted. We planned to reconstruct the lower extremity defect with a free flap, but the vessel status was severely compromised intraoperatively. Thus, we found the anterior tibial artery perforator using Doppler ultrasound, elevated the tibialis anterior muscle segment flap, and transposed it to cover the defect successfully. The flap presented with a nice contour and the skin graft covering the flap survived completely. There were no complications of the surgical site at three months follow-up and no gait morbidity. This is a meaningful case applying the concept of segmental muscle flap based on a perforator that had advantages including proper bulkiness, vascularization, and preservation of function, which were well applied, leading to great success.