title: Individuals with chronic low back pain do not modulate the level of transversus abdominis muscle contraction across different postures.
abstract: The aim of this study was to evaluate the thickness of the transversus abdominis (TrA) muscle in three basic postures in subjects with and without chronic low back pain. Subjects were classified into a chronic low back pain group (n = 27) and a healthy control group (n = 23). The thickness of the TrA muscle was measured at rest and during the abdominal drawing-in manoeuvre (ADIM) in supine, sitting and standing postures using B-mode ultrasound imaging. Contraction ratio (TrA thickness during the ADIM/TrA thickness at rest) was calculated for each posture. At rest, the TrA thickness in the sitting and standing postures was significantly greater than in the supine posture (p < 0.017) in the control group, but similar in all three postures in the low back pain group. TrA thickness was similar in the low back pain and control group in all three postures. During the ADIM, TrA thickness was significantly greater in the control group than in the chronic low back pain group in all three postures. The contraction ratio was also significantly higher in the control group than in the chronic low back pain group in all three postures. These results indicate that the automatic postural contraction of the TrA observed in the control subjects in the sitting and standing postures was not demonstrated in subjects with chronic low back pain. The present study revealed the one aspect of different response of the TrA muscle to changing posture between two groups.
authors.affiliation: Graduate School of Health Sciences, Hokkaido University, Sapporo, Hokkaido, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Miura
authors.affiliation: Faculty of Health Sciences, Hokkaido University, West 5, North 12, Kita-ku, Sapporo 060-0812, Hokkaido, Japan. Electronic address: yamanaka@hs.hokudai.ac.jp.
authors.forename: Masanori
authors.initials: M
authors.lastname: Yamanaka
authors.affiliation: Hakodate Orthopedics Clinic, Hakodate, Hokkaido, Japan.
authors.forename: Kengo
authors.initials: K
authors.lastname: Ukishiro
authors.affiliation: Faculty of Health Sciences, Hokkaido University, West 5, North 12, Kita-ku, Sapporo 060-0812, Hokkaido, Japan.
authors.forename: Harukazu
authors.initials: H
authors.lastname: Tohyama
authors.affiliation: Faculty of Health Sciences, Hokkaido University, West 5, North 12, Kita-ku, Sapporo 060-0812, Hokkaido, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Saito
authors.affiliation: Faculty of Health Sciences, Hokkaido University, West 5, North 12, Kita-ku, Sapporo 060-0812, Hokkaido, Japan.
authors.forename: Mina
authors.initials: M
authors.lastname: Samukawa
authors.affiliation: Hokkaido Chitose Institute of Rehabilitation Technology, Chitose, Hokkaido, Japan.
authors.forename: Takumi
authors.initials: T
authors.lastname: Kobayashi
authors.affiliation: Department of Physical Therapy, Hokkaido University of Science, Sapporo, Hokkaido, Japan.
authors.forename: Takumi
authors.initials: T
authors.lastname: Ino
authors.affiliation: Department of Orthopedic Surgery, Hokuto Hospital, Obihiro, Hokkaido, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Takeda
mesh_terms: D000009:Abdominal Muscles / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D016022:Case-Control Studies; D002908:Chronic Disease; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*; D011187:Posture / Q000502:physiology*; D015203:Reproducibility of Results; D014463:Ultrasonography; D055815:Young Adult
keywords: Automatic contraction; Chronic low back pain; Posture; Transversus abdominis muscle