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Fujitani R1, Jiroumaru T1, Wachi M2
1Shiga School of Medical Technology, Department of Physical Therapy, Shiga Higashiomi, Japan, 2Knazawa Orthopaedic and Sports Medicine Clinic, Physical Therapy, Shiga Rittou, Japan
Background: Lordosis (LO) and Sway-back posture (SW) are the typical postural abnormalities associated with low back pain. Altered activities in the abdominal muscles and hip flexors have been reported in the SW during standing. Such muscle imbalances would impose increased stress on the joints and surrounding structures, which may be the cause of the pain. However, previous research has only investigated trunk muscles, and investigation that includes muscles of the hip joint has yet to be conducted. Additionally, postural deviations that was previously subjected to research only included SW, while LO was not investigated.
Purpose: The purpose of this study is to elucidate the association between posture and low back pain by assessing, on the basis of previous research, muscle activity of the trunk and hip joint in healthy adults with no postural problems while they attempt three different postural conditions neutral and sway-back and lordosis and to obtain basic insights into postural improvement by clarifying the association between spinal posture and muscle control.
Methods: Seventeen healthy young male adults were instructed to maintain three different postures: Neutral (NU), SW, and LO, while standing. Electromyographic (EMG) data were collected at 1000Hz to measure activity in the trunkl muscles:
(1) rectus abdominis,
(2) external oblique,
(3) thoracic elector spinae,
(4) internal oblique and
(5) lumbar multifidus, as well as hip muscles:
(6) iliopsoas,
(7) sartorius,
(8) rectus femoris,
(9)tensor fasciae latae,
(10,11) upper and lower portion of the gluteus maximus.
RMS amplitude of the band-pass filtered EMG signals (20-500Hz) was calculated as the mean and normalized to the relevant MVC.
Results: SW as compared with NU muscle activity of the trunk, SW showed an increase (p 0.05) in the rectus abdominis muscle and a decrease (p 0.05) in the internal oblique muscle. Additionally, in the hip joint, there was a significant decrease (p 0.05) in the iliopsoas as well as the upper and lower parts of the gluteus maximus muscle. Next, LO showed increased activity (p 0.05) of the iliocostalis dorsi, iliocostalis lumborum, and lumbar multifidus muscles in the trunk compared to NU. Furthermore, activity of the lower portion of the gluteus maximus muscle was significantly decreased (p 0.05) in the hip joint.
Conclusion(s): The experiment in this study was conducted with the purpose of clarifying the relationship between the muscles of the trunk/hip joint and spino-pelvic curvature by comparing and evaluating muscle activity of healthy adult men while they attempted the basic standing posture (NU) and two postural deviations (SW and LO). The results of this study revealed that postural changes affect activity of the muscles in the hip joint and trunk that are involved in maintaining posture. Changes in muscle control caused by postural changes suggest that a different kind of stress is generated in the lumbar area while attempting a postural deviations.
Implications: These findings are fundamental for clarifying the association between postural deviations and low back pain, and in postural reeducation.
Keywords: Sanding posture, Low back pain, Muscle activity
Funding acknowledgements: None.
Purpose: The purpose of this study is to elucidate the association between posture and low back pain by assessing, on the basis of previous research, muscle activity of the trunk and hip joint in healthy adults with no postural problems while they attempt three different postural conditions neutral and sway-back and lordosis and to obtain basic insights into postural improvement by clarifying the association between spinal posture and muscle control.
Methods: Seventeen healthy young male adults were instructed to maintain three different postures: Neutral (NU), SW, and LO, while standing. Electromyographic (EMG) data were collected at 1000Hz to measure activity in the trunkl muscles:
(1) rectus abdominis,
(2) external oblique,
(3) thoracic elector spinae,
(4) internal oblique and
(5) lumbar multifidus, as well as hip muscles:
(6) iliopsoas,
(7) sartorius,
(8) rectus femoris,
(9)tensor fasciae latae,
(10,11) upper and lower portion of the gluteus maximus.
RMS amplitude of the band-pass filtered EMG signals (20-500Hz) was calculated as the mean and normalized to the relevant MVC.
Results: SW as compared with NU muscle activity of the trunk, SW showed an increase (p 0.05) in the rectus abdominis muscle and a decrease (p 0.05) in the internal oblique muscle. Additionally, in the hip joint, there was a significant decrease (p 0.05) in the iliopsoas as well as the upper and lower parts of the gluteus maximus muscle. Next, LO showed increased activity (p 0.05) of the iliocostalis dorsi, iliocostalis lumborum, and lumbar multifidus muscles in the trunk compared to NU. Furthermore, activity of the lower portion of the gluteus maximus muscle was significantly decreased (p 0.05) in the hip joint.
Conclusion(s): The experiment in this study was conducted with the purpose of clarifying the relationship between the muscles of the trunk/hip joint and spino-pelvic curvature by comparing and evaluating muscle activity of healthy adult men while they attempted the basic standing posture (NU) and two postural deviations (SW and LO). The results of this study revealed that postural changes affect activity of the muscles in the hip joint and trunk that are involved in maintaining posture. Changes in muscle control caused by postural changes suggest that a different kind of stress is generated in the lumbar area while attempting a postural deviations.
Implications: These findings are fundamental for clarifying the association between postural deviations and low back pain, and in postural reeducation.
Keywords: Sanding posture, Low back pain, Muscle activity
Funding acknowledgements: None.
Topic: Human movement analysis; Musculoskeletal: spine
Ethics approval required: Yes
Institution: Aino University
Ethics committee: Ethics Review Board, Aino University
Ethics number: Aino-2013-02
All authors, affiliations and abstracts have been published as submitted.
