Yoshiki Motomura1, Hiroshige Tateuchi2, Tomohito Komamura3, Yuta Yagi4, Sayaka Nakao2, Noriaki Ichihashi2. 1. Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Kyoto, Japan. motomura.yoshiki.32z@kyoto-u.jp. 2. Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Kyoto, Japan. 3. Division of Rehabilitation Medicine, Chiba University Hospital, Chiba, Chiba, Japan. 4. Department of Rehabilitation, Rinku General Medical Center, Izumisano, Osaka, Japan.
Abstract
PURPOSE: Abdominal hollowing exercise has been recommended to improve trunk stability. Trunk lean and foot lift exercises while sitting may easily promote abdominal muscle activity even in people who cannot perform abdominal hollowing consciously. The purpose of the present study was to examine the changes in abdominal muscle activity and contribution rate of the transversus abdominis muscle (TrA) when leaning the trunk and lifting the foot during sitting. METHODS: The muscle stiffnesses (indicators of muscle activity) of the right rectus abdominis, external oblique, internal oblique, and TrA of 14 healthy men were measured during abdominal hollowing and the following nine sitting tasks: reference posture, 15° and maximal posterior trunk lean, 20° and maximal ipsilateral and contralateral trunk lean, and ipsilateral and contralateral foot lift. The TrA contribution rate was calculated by dividing the TrA stiffness by the sum of the abdominal muscles' stiffnesses. RESULTS: The TrA stiffness was significantly higher in abdominal hollowing than in reference posture, posterior and ipsilateral trunk lean, and ipsilateral foot lift, but not higher than in contralateral trunk lean and contralateral foot lift. There was no significant difference in the TrA contribution rates between abdominal hollowing and ipsilateral or contralateral foot lift. CONCLUSION: The contralateral trunk lean or contralateral foot lift could enhance TrA activity for people who cannot perform abdominal hollowing consciously. The contralateral foot lift could particularly be beneficial to obtain selective activity of TrA.
PURPOSE: Abdominal hollowing exercise has been recommended to improve trunk stability. Trunk lean and foot lift exercises while sitting may easily promote abdominal muscle activity even in people who cannot perform abdominal hollowing consciously. The purpose of the present study was to examine the changes in abdominal muscle activity and contribution rate of the transversus abdominis muscle (TrA) when leaning the trunk and lifting the foot during sitting. METHODS: The muscle stiffnesses (indicators of muscle activity) of the right rectus abdominis, external oblique, internal oblique, and TrA of 14 healthy men were measured during abdominal hollowing and the following nine sitting tasks: reference posture, 15° and maximal posterior trunk lean, 20° and maximal ipsilateral and contralateral trunk lean, and ipsilateral and contralateral foot lift. The TrA contribution rate was calculated by dividing the TrA stiffness by the sum of the abdominal muscles' stiffnesses. RESULTS: The TrA stiffness was significantly higher in abdominal hollowing than in reference posture, posterior and ipsilateral trunk lean, and ipsilateral foot lift, but not higher than in contralateral trunk lean and contralateral foot lift. There was no significant difference in the TrA contribution rates between abdominal hollowing and ipsilateral or contralateral foot lift. CONCLUSION: The contralateral trunk lean or contralateral foot lift could enhance TrA activity for people who cannot perform abdominal hollowing consciously. The contralateral foot lift could particularly be beneficial to obtain selective activity of TrA.
Authors: Martin Eriksson Crommert; Kylie Tucker; Christopher Holford; Alexander Wight; Donna McCook; Paul Hodges Journal: J Electromyogr Kinesiol Date: 2017-05-17 Impact factor: 2.368
Authors: Luciana Gazzi Macedo; Christopher G Maher; Mark J Hancock; Steve J Kamper; James H McAuley; Tasha R Stanton; Ryan Stafford; Paul W Hodges Journal: Phys Ther Date: 2014-07-10