To deepen understanding of the normal for sitting from supine, 10 men and women were examined using motion analysis and electromyography. Motion was classified into three categories, namely sitting from supine with arm support on one side, sitting from supine with arm support on both sides, and sitting from supine with the sitting position with extended legs. The muscle activities of the right and left rectus abdominis muscles and right and left abdominal oblique muscle overlapping sites were examined using electromyography. A common feature of the three motions was the absence of rotation or side bending of the trunk. In addition, as segmental rotation and lateral bending of the trunk do not occur, the activities of the upper limbs are suggested to be important with regard to raising and rotating the body.