title: Association of sagittal spinal alignment with thickness and echo intensity of lumbar back muscles in middle-aged and elderly women.
abstract: OBJECTIVE
  Quantitative changes, such as a decrease in muscle mass, and qualitative changes, such as an increase in the amount of intramuscular non-contractile tissue, occur with aging. However, it is unclear whether quantitative or qualitative changes in back muscles are associated with spinal alignment in the standing position. We investigated the association of sagittal spinal alignment with muscle thickness as an index of the mass of lumbar back muscles and muscle echo intensity as an index of the amount of non-contractile tissue within these muscles.
  
  
  METHODS
  Study participants comprised 36 middle-aged and elderly women. Thickness and echo intensity of erector spinae, psoas major, and lumbar multifidus muscles were measured using an ultrasound imaging device. Standing sagittal spinal alignment, determined from thoracic kyphosis and lumbar lordosis angles, and the sacral anterior inclination angle was measured using the Spinal Mouse.
  
  
  RESULTS
  Stepwise regression analysis performed using muscle thickness, echo intensity, and age as independent variables showed that erector spinae muscle thickness was a significant determinant of the thoracic kyphosis angle. Psoas major muscle thickness and echo intensity of the lumbar multifidus muscle were significant determinants of the sacral anterior inclination angle.
  
  
  CONCLUSIONS
  Our results suggest that an increase in thoracic kyphosis is associated with a decrease in the mass of the erector spinae muscle, and that a decrease in pelvic anterior inclination is associated with a decrease in the mass of the psoas major muscle and an increase in the amount of non-contractile tissue within the lumbar multifidus muscle.
authors.affiliation: Department of Physical Therapy, Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan. Electronic address: masaki.mitsuhiro.27w@st.kyoto-u.ac.jp.
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Masaki
authors.affiliation: Department of Physical Therapy, Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan.
authors.forename: Tome
authors.initials: T
authors.lastname: Ikezoe
authors.affiliation: Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, Hyogo 518 Arise, Ikawadani-cho, Nishi-ku, Kobe 651-2180, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Fukumoto
authors.affiliation: Department of Occupational Therapy, Faculty of Allied Health Sciences, Yamato University, Osaka 2-5-1 Katayama-cho, Suita 564-0082, Japan.
authors.forename: Seigo
authors.initials: S
authors.lastname: Minami
authors.affiliation: Department of Physical Therapy, Faculty of Rehabilitation, Hyogo University of Health Sciences, Hyogo 1-3-6 Minatojima, Chuo-ku, Kobe 650-8530, Japan.
authors.forename: Rui
authors.initials: R
authors.lastname: Tsukagoshi
authors.affiliation: Department of Physical Therapy, Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan; Japan Society for the Promotion of Science, Tokyo 5-3-1 Kojimachi-cho, Chiyoda-ku, Tokyo 102-0083, Japan.
authors.forename: Kaoru
authors.initials: K
authors.lastname: Sakuma
authors.affiliation: Department of Physical Therapy, Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan.
authors.forename: Satoko
authors.initials: S
authors.lastname: Ibuki
authors.affiliation: Department of Nutritional Science, National Institute of Health and Nutrition, Tokyo 1-23-1 Toyama, Shinjyuku-ku, Tokyo 162-8636, Japan.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Yamada
authors.affiliation: Faculty of Bioenvironmental Science, Kyoto Gakuen University, Kyoto 1-1 Nanjyo-Otani, Sogabe-cho, Kameoka 621-8555, Japan.
authors.forename: Misaka
authors.initials: M
authors.lastname: Kimura
authors.affiliation: Department of Physical Therapy, Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan.
authors.forename: Noriaki
authors.initials: N
authors.lastname: Ichihashi
mesh_terms: D000368:Aged; D000375:Aging / Q000502:physiology; D064131:Back Muscles / Q000000981:diagnostic imaging; D005260:Female; D005684:Gait; D006801:Humans; D007564:Japan; D007738:Kyphosis / Q000000981:diagnostic imaging*; D008141:Lordosis / Q000000981:diagnostic imaging; D008161:Lumbosacral Region / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology*; D064170:Paraspinal Muscles; D010809:Physical Fitness / Q000502:physiology*; D011187:Posture; D012044:Regression Analysis; D013131:Spine / Q000502:physiology*; D014463:Ultrasonography
keywords: Aged; Middle-aged; Paraspinal muscles; Posture; Ultrasonography