This paper reports the case of a 27-year-old man with complete L1 spinal cord injury caused by a work accident and describes the care he received through his physiological and psychological adjustment process in response to changes in physical functioning. Throughout the therapy period from November 6 to December 25, 2016, the author conducted holistic assessments using Roy’s Adaptation Model. Information collected from participant observations, direct care, physical assessments, medical records, and conversations confirmed that major health issues included impaired physical activity and functioning, dysfunctional voiding, and powerlessness. Holistic care measures were applied to the patient during the care period. Physical therapy was provided to strengthen limb activity, and bladder training was administered to improve urination. Furthermore, the patient was guided to express his feelings through proactive attention and support, active listening, and the sharing of posttraumatic physiological and psychological adjustment methods. The patient was also provided with opportunities to interact with other people and was encouraged to participate in support groups such as the Association of Spinal Cord Injury. This increases his confidence in confronting disease and facilitates the development of a positive attitude regarding the value of life. These, along with ameliorating feelings of powerlessness, can improve the patient’s quality of life.