Effects of posture on the thickness of transversus abdominis in pain-free subjects

19th Street Physiotherapy Clinic, Vancouver V7M1X5, Canada.
Manual therapy (Impact Factor: 1.71). 06/2009; 14(6):679-84. DOI: 10.1016/j.math.2009.02.008
Source: PubMed


The role of transversus abdominis (TrA) on spinal stability may be important in low back pain (LBP). To date, there have not been any investigations into the influence of lumbo-pelvic neutral posture on TrA activity. The present study therefore examines whether posture influences TrA thickness. A normative within-subjects single-group study was carried out. Twenty healthy adults were recruited and taught five postures: (1) supine lying; (2) erect sitting (lumbo-pelvic neutral); (3) slouched sitting; (4) erect standing (lumbo-pelvic neutral); (5) sway-back standing. In each position, TrA thickness was measured (as an indirect measure of muscle activity) using ultrasound. In erect standing, TrA (mean TrA thickness: 4.63+/-1.35 mm) was significantly thicker than in sway-back standing (mean TrA thickness: 3.32+/-0.95 mm) (p=00001). Similarly, in erect sitting TrA (mean thickness=4.30 mm+/-1.58 mm) was found to be significantly thicker than in slouched sitting (mean thickness=3.46 mm+/-1.13 mm) (p=0002). In conclusion, lumbo-pelvic neutral postures may have a positive influence on spinal stability compared to equivalent poor postures (slouched sitting and sway-back standing) through the recruitment of TrA. Therefore, posture may be important for rehabilitation in patients with LBP.

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    • "On the other hand, other studies suggest that the abdominal muscles are essential for the formation of spinal curvatures in the saggital planes (Lam and Mehdian, 1999). Studies performed in the adult population have confirmed that an increase in the TrA muscle thickness in neutral positions of the spine indicates this role of this muscle in posture (Reeve and Dilley, 2009). Therefore, it is reasonable to look for further relationships between the thickness of the abdominal muscles and body posture and/or LBP in children and adolescents. "
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    ABSTRACT: Lateral abdominal wall muscles in children and adolescents have not been characterised to date. In the present report, we examined the reliability of the ultrasound measurement and thickness of the oblique external muscle (OE), oblique internal muscle (OI) and transverse abdominal muscle (TrA) at rest and during abdominal drawing-in manoeuvre (ADIM) on both sides of the body in healthy adolescents. We also determined possible differences between boys and girls and defined any factors—such as body mass, height and BMI—that may affect the thickness of the abdominal muscles. B-mode ultrasound was used to assess OE, OI and TrA on both sides of the body in the supine position. Ultrasound measurements at rest and during ADIM were reliable in this age group (ICC3,3>0.92). OI was always the thickest and TrA the thinnest muscle on both sides of the body. In this group, an identical pattern of the contribution of the individual muscles to the structure of the lateral abdominal wall (OI>OE>TrA) was observed. At rest and during ADIM, no statistically significant side-to-side differences were demonstrated in either gender. The body mass constitutes between 30% and <50% of the thickness differences in all muscles under examination at rest and during ADIM. The structure of lateral abdominal wall in adolescents is similar to that of adults. During ADIM, the abdominal muscles in adolescents react similarly to those in adults. This study provided extensive information regarding the structure of the lateral abdominal wall in healthy adolescents.
    Manual Therapy 07/2014; 20(1). DOI:10.1016/j.math.2014.07.009 · 1.71 Impact Factor
    • "While posture 5 involves less lumbar lordosis than posture 9, it also involves considerably greater thoracic extension and forward trunk lean. Therefore, posture 5 is likely to be associated with higher levels of muscle activation, particularly of muscles such as thoracic erector spinae, iliocostalis longissimus pars thoracis and external oblique (O'Sullivan et al., 2006; Claus et al., 2009b; Reeve and Dilley, 2009). As a result, posture 5 may be associated with greater fatigue and potential discomfort (Lander et al., 1987). "
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    ABSTRACT: While sitting is a common aggravating factor in low back pain (LBP), the best sitting posture remains unclear. This study investigated the perceptions of 295 physiotherapists in four different European countries on sitting posture. Physiotherapists selected their perceived best sitting posture from a sample of nine options that ranged from slumped to upright sitting, as well as completing the back beliefs questionnaire (BBQ). 85% of physiotherapists selected one of two postures as best, with one posture being selected significantly more frequently than the remainder (p < 0.05). Interestingly, these two most frequently selected postures were very different from each other. Those who selected the more upright sitting posture had more negative LBP beliefs on the BBQ (p < 0.05). The choice of best sitting posture also varied between countries (p < 0.05). Overall, disagreement remains on what constitutes a neutral spine posture, and what is the best sitting posture. Qualitative comments indicated that sitting postures which matched the natural shape of the spine, and appeared comfortable and/or relaxed without excessive muscle tone were often deemed advantageous. Further research on the perceptions of people with LBP on sitting posture are indicated.
    Manual therapy 05/2012; 17(5):432-7. DOI:10.1016/j.math.2012.04.007 · 1.71 Impact Factor
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    • "It has been proposed that an optimal sitting posture for LBP subjects who are sensitised to flexion or extension is a more neutral spine position involving slight lumbar lordosis and a relaxed thorax (O'Sullivan et al., 2006a). This neutral posture avoids potentially painful end-range positions (Scannell and McGill, 2003), as well as activating key trunk muscles (O'Sullivan et al., 2006a; Claus et al., 2009b; Reeve and Dilley, 2009). However, assuming such a posture may be difficult to adopt (Claus et al., 2009a), questioning its application in clinical practice. "
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    ABSTRACT: Sitting is a common aggravating factor in low back pain (LBP), and re-education of sitting posture is a common aspect of LBP management. However, there is debate regarding what is an optimal sitting posture. This pilot study had 2 aims; to investigate whether pain-free subjects can be reliably positioned in a neutral sitting posture (slight lumbar lordosis and relaxed thorax); and to compare perceptions of neutral sitting posture to habitual sitting posture (HSP). The lower lumbar spine HSP of seventeen pain-free subjects was initially recorded. Subjects then assumed their own subjectively perceived ideal posture (SPIP). Finally, 2 testers independently positioned the subjects into a tester perceived neutral posture (TPNP). The inter-tester reliability of positioning in TPNP was very good (intraclass correlation coefficient (ICC) = 0.91, mean difference = 3% of range of motion). A repeated measures ANOVA revealed that HSP was significantly more flexed than both SPIP and TPNP (p <0.05). There was no significant difference between SPIP and TPNP (p > 0.05). HSP was more kyphotic than all other postures. This study suggests that pain-free subjects can be reliably positioned in a neutral lumbar sitting posture. Further investigation into the role of neutral sitting posture in LBP subjects is warranted.
    Manual therapy 12/2010; 15(6):557-61. DOI:10.1016/j.math.2010.06.005 · 1.71 Impact Factor
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