title: Abdominal muscle activity according to knee joint angle during sit-to-stand.
abstract: [Purpose] This study assessed the activity of the abdominal muscles according to the angle of the knee joints during sit-to-stand. [Subjects and Methods] Thirty healthy adult males participated in this study. Subjects initiated sit-to-stand at knee joint angles of 60°, 90°, or 120°. An electromyography system was used to measure the maximum voluntary isometric contraction of the rectus abdominis, external oblique, and internal oblique and transverse abdominis muscles. [Results] Percent contraction differed significantly among the three knee joint angles, most notably for the internal oblique and transverse abdominis muscles. [Conclusion] Wider knee joint angles more effectively activate the abdominal muscles, especially those in the deep abdomen, than do narrower angles.
authors.affiliation: Department of Physical Therapy, Graduate School, Catholic University of Pusan, Republic of Korea.
authors.forename: Juri
authors.initials: J
authors.lastname: Eom
authors.affiliation: Department of Rehabilitation Medicine, Pusan National University Hospital, Republic of Korea.
authors.forename: Min-Hyung
authors.initials: MH
authors.lastname: Rhee
authors.affiliation: Department of Physical Therapy, College of Health Sciences, Catholic University of Pusan, Republic of Korea.
authors.forename: Laurentius Jongsoon
authors.initials: LJ
authors.lastname: Kim
keywords: Abdominal; Knee joint; Sit-to-stand