The goal of this observational study is to evaluate respiratory and limb muscle properties in adults awaiting lung transplantation and determine how these measures relate to physical performance, symptoms, and recovery after transplantation. Respiratory and limb muscle weakness may contribute to impaired mobility, frailty, and delayed postoperative recovery, but their specific role in lung transplant candidates is not well understood. Participants will undergo muscle ultrasound imaging at weekly basis, respiratory and limb strength testing, physical performance assessments, and symptom questionnaires once before and after transplantation. Researchers will also collect information from medical records regarding intensive care unit stay, hospital length of stay, rehabilitation participation, and postoperative recovery outcomes.