@phdthesis{oai:ir.kagoshima-u.ac.jp:00015001,
 author = {中井, 雄貴 and Nakai, Yuki},
 month = {2021-04-09, 2020-03-17, 2020-03-17, 2020-03-17},
 note = {博士論文全文, 博士論文要旨, 最終試験結果の要旨, 論文審査の要旨, Introduction
The purpose of this study was to clarify the muscle activation during trunk stabilizing exercise with isometric hip rotation in healthy males by comparing that with abdominal crunch (AC) and active straight leg raise (ASLR). Electromyography and ultrasound imaging were used to simultaneously measure muscle activity and thickness of the internal oblique (IO), the external oblique (EO), transverse abdominis (TrA) and multifidus (MF) on the right side during exercise.
Methods
Twenty healthy participants performed the following exercises in supine position: isometric right or left hip internal/external rotation, AC, and ASLR. Muscle activity was normalized to maximum voluntary contraction (MVC), and muscle thickness was normalized to resting muscle thickness.
Results
Muscle activation and thickness of IO, MF and TrA increased significantly during the isometric hip rotation compared with other exercises. Muscle activation during the trunk stabilizing exercise with ipsilateral isometric hip internal rotation was 21% in IO, 26% in MF, and with ipsilateral hip external rotation was 12% of MVC in EO.
Conclusion
These findings suggest that trunk stabilizing exercise with isometric hip rotation exercise may be a more safe and effective exercise to promote trunk muscle activity than AC and ASLR. These findings would be beneficial for therapists engaged in prevention and treatment of low back pain.

Yuki Nakai, Masayuki Kawada, Takasuke Miyazaki, Ryoji Kiyama
Trunk muscle activity during trunk stabilizing exercise with isometric hip rotation using electromyography and ultrasound
Journal of Electromyography and Kinesiology 49, December 2019, 102357
https://doi.org/10.1016/j.jelekin.2019.102357},
 school = {鹿児島大学},
 title = {Trunk muscle activity during trunk stabilizing exercise with isometric hip rotation using electromyography and ultrasound},
 year = {},
 yomi = {ナカイ, ユウキ}
}