Comparison of the Ultrasonic Thickness of Abdominal Wall Muscles in Women with and Without Sway Back Posture

Sway Back Posture (SBP) is one of the most common postural disorders in young people. Considering the importance of the role of the abdominal wall muscles in preserving and maintaining normal posture, it is necessary to investigate the relationship between this postural disorder and the function of the abdominal wall muscles. The present study aimed to compare the ultrasonic thickness of the abdominal wall muscles between women with and without SBP.

 A total of 111 women, aged 18-30 years were divided into two groups of 37 with SBP and 74 without SBP, participated in the current analytical study. Kendall method was used to evaluate postural status. To measure the degree of lumbar lordosis and anterior pelvic tilt, a flexible ruler and pelvic inclinometer were used, respectively. The rest thicknesses of the abdominal wall muscles, including the rectus abdominis, external oblique, internal oblique, and transversus abdominis, were measured using B Mode ultrasonography in both supine and standing positions.

There were no significant differences in resting thickness of all abdominal muscles between the two groups in the supine position (p≥0. 05). In the standing position, only the external oblique muscle showed a significant difference (p = 0.03). In women with SBP, lumbar lordosis was greater and the pelvic tilt was less than that of women without SBP (p<0.05). In both groups, muscle thickness increased as body mass index increased (p <0.05).

The lack of a change or reduction in the thickness of the abdominal wall muscles in women with SBP can be due to the stability created by the passive elements; consequently, there is no need for muscle activity. Accordingly, evaluation of the contractile thickness of the abdominal wall muscles in people with SBP is recommended.