Mitsuhiro Masaki1, Tome Ikezoe2, Yoshihiro Fukumoto3, Seigo Minami4, Junichi Aoyama5, Satoko Ibuki2, Misaka Kimura6, Noriaki Ichihashi2. 1. Department of Physical Therapy, Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan. masaki.mitsuhiro.27w@st.kyoto-u.ac.jp. 2. Department of Physical Therapy, Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan. 3. Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, Hyogo, 518 Arise, Ikawadani-cho, Nishi-ku, Kobe, 651-2180, Japan. 4. Department of Occupational Therapy, Faculty of Allied Health Sciences, Yamato University, Osaka, 2-5-1 Katayama-cho, Suita, 564-0082, Japan. 5. Department of Rehabilitation, Kyoto Yawata Hospital, Kyoto, 61 Kawaguchi-Bessho, Yawata, 614-8114, Japan. 6. Faculty of Health and Medical Science, Kyoto Gakuen University, Kyoto, 1-1 Nanjyo-Otani, Sogabe-cho, Kameoka, 621-8555, Japan.
Abstract
BACKGROUND: Age-related change of spinal alignment in the standing position is known to be associated with decreases in walking speed, and alteration in muscle quantity (i.e., muscle mass) and muscle quality (i.e., increases in the amount of intramuscular non-contractile tissue) of lumbar back muscles. Additionally, the lumbar lordosis angle in the standing position is associated with walking speed, independent of lower-extremity muscle strength, in elderly individuals. However, it is unclear whether spinal alignment in the standing position is associated with walking speed in the elderly, independent of trunk muscle quantity and quality. The present study investigated the association of usual and maximum walking speed with age, sagittal spinal alignment in the standing position, muscle quantity measured as thickness, and quality measured as echo intensity of lumbar muscles in 35 middle-aged and elderly women. METHODS: Sagittal spinal alignment in the standing position (thoracic kyphosis, lumbar lordosis, and sacral anterior inclination angle) using a spinal mouse, and muscle thickness and echo intensity of the lumbar muscles (erector spinae, psoas major, and lumbar multifidus) using an ultrasound imaging device were also measured. RESULTS: Stepwise regression analysis showed that only age was a significant determinant of usual walking speed. The thickness of the lumbar erector spinae muscle was a significant, independent determinant of maximal walking speed. CONCLUSIONS: The results of this study suggest that a decrease in maximal walking speed is associated with the decrease in lumbar erector spinae muscles thickness rather than spinal alignment in the standing position in middle-aged and elderly women.
BACKGROUND: Age-related change of spinal alignment in the standing position is known to be associated with decreases in walking speed, and alteration in muscle quantity (i.e., muscle mass) and muscle quality (i.e., increases in the amount of intramuscular non-contractile tissue) of lumbar back muscles. Additionally, the lumbar lordosis angle in the standing position is associated with walking speed, independent of lower-extremity muscle strength, in elderly individuals. However, it is unclear whether spinal alignment in the standing position is associated with walking speed in the elderly, independent of trunk muscle quantity and quality. The present study investigated the association of usual and maximum walking speed with age, sagittal spinal alignment in the standing position, muscle quantity measured as thickness, and quality measured as echo intensity of lumbar muscles in 35 middle-aged and elderly women. METHODS: Sagittal spinal alignment in the standing position (thoracic kyphosis, lumbar lordosis, and sacral anterior inclination angle) using a spinal mouse, and muscle thickness and echo intensity of the lumbar muscles (erector spinae, psoas major, and lumbar multifidus) using an ultrasound imaging device were also measured. RESULTS: Stepwise regression analysis showed that only age was a significant determinant of usual walking speed. The thickness of the lumbar erector spinae muscle was a significant, independent determinant of maximal walking speed. CONCLUSIONS: The results of this study suggest that a decrease in maximal walking speed is associated with the decrease in lumbar erector spinae muscles thickness rather than spinal alignment in the standing position in middle-aged and elderly women.