Comparison of the sonographic features of the abdominal wall muscles and connective tissues in individuals with and without lumbopelvic pain.

Whittaker, Jackie.L., Warner, Martin and Stokes, Maria (2013) Comparison of the sonographic features of the abdominal wall muscles and connective tissues in individuals with and without lumbopelvic pain. Journal of Orthopaedic and Sports Physical Therapy, 43 (1), 11-19. (doi:10.2519/jospt.2013.4450). (PMID:23160368)

Abstract

Study Design: Cross sectional, case-control study.
Objectives: Measure and compare the resting thickness of the four abdominal wall muscles, their associated perimuscular connective tissue (PMCT), and inter-recti distance (IRD) in persons with and without lumbopelvic pain (LPP), using ultrasound imaging (USI).
Background: The muscles and PMCT of the abdominal wall assist in controlling the spine and functional deficits have been detected in LPP populations. Investigations of the abdominal wall in LPP are primarily concerned with muscle, most commonly the transversus abdominis (TrA) and internal oblique (IO). As the abdominal wall functions as a unit, it seems prudent that all 4 abdominal muscles and their associated connective tissues are considered concurrently.
Methods: B-mode USI was used to measure the resting thickness of the rectus abdominis (RA), external oblique (EO), IO, and TrA muscles, the PMCT planes, and IRD in 50 male and female subjects (25 with and 25 without LPP; mean +/- SD age 36.3 +/- 9.4 and 46.6 +/- 8.0 years, respectively). Univariate correlation analysis was used to identify covariates. Analyses of covariance and Kruskal-Wallis test (IRD) were used to compare cohorts (alpha=0.05).
Results: The LPP cohort had less total abdominal muscle thickness (LPP 18.9 +/- 3.0 mm, Control 20.3 +/- 3.0 mm; ANCOVA adjusted for body mass index [BMI], P=.03), thicker PMCT (LPP 5.5 +/- 0.2 mm, Control 4.3 +/- 0.2 mm; ANCOVA adjusted for BMI, P=.007), and wider IRD (LPP 11.5 +/- 2.0 mm, Control 8.4 +/- 1.8 mm; Kruskal-Wallis, P=.005). Analysis of individual muscle thickness revealed no difference in the EO, IO, and TrA, but a thinner RA (LPP 7.8 +/- 1.5 mm, Control 9.1 +/- 1.2 mm; 56 ANCOVA adjusted for BMI, P<.001) in the LPP cohort.
Conclusions: To our knowledge this is the first study to investigate the morphological characteristics of all 4 abdominal muscles and PMCT in individuals with LPP. The results suggest altered loading of the PMCT and linea alba, which may be secondary to an altered motor control strategy that involves a reduced contribution of the RA. Further, the change in RA and connective tissue morphology may be more evident than changes in EO, IO, and TrA thickness in persons with LPP. The causes and functional implications of these changes warrant further investigation, as does the role of the RA muscle in the development and persistence of LPP.

This record has no associated files available for download.

Contributors

Author: Martin Warner

Author: Maria Stokes

Download statistics