The restoration of motor function is important in daily life in patients with brain damage. Although attentional concentration can affect motor function, most physical therapists focus only on therapeutic exercise. Therefore, we investigated changes in motor function in patients with high attentional concentration during our intervention. A total of 21 subjects diagnosed with stroke participated in the study. They were divided into the high attentional concentration group and low attentional concentration group based on the self-programmed attention index. The subjects underwent trunk strengthening and gait training for 30 min per session, twice a day, 5 days a week, for a total of 4 weeks. All patients wore electroencephalogram (EEG) devices during the treatment to enable EEG examinations. Diagnostic ultrasound was used to measure muscles of the abdomen: external oblique abdominal, internal oblique abdominal, transversus abdominis, and rectus abdominal muscles. A trunk impairment scale was used to evaluate trunk control. We used Gaitrite to measure the spatial and temporal components during gait. The group with high attentional concentration showed significant differences in abdominal muscle strength and trunk control. In gait, there was a significant difference in swing cycle, stance cycle, single cycle, double support cycle, stance time, and double support time. Therefore, attentional concentration should be considered to improve motor function as a part of therapeutic exercises for stroke patients.