Ultrasound Imaging Assessment of Abdominal Muscle Function During Drawing-in of the Abdominal Wall: An Intrarater Reliability Study

Abstract

A ssessment of function of the deep abdominal musculature in the laboratory has largely used methodologies such as functional movement tasks and fine-wire electromyography (EMG). 13,10,11,15,27 While fine-wire EMG is primarily restricted to laboratory research, rehabilitative ultrasound imaging (RUSI) offers a noninvasive and simpler method of assessing deep lumbopelvic muscle function. Recent work has shown that measures of transversus abdominis (TrA) muscle contraction, 20 internal oblique (IO) muscle contraction, and length of the TrA muscle obtained using RUSI correlated well with measures obtained by fine-wire EMG for isometric contractions of these muscles. 12,20 For increases in thickness of the TrA and IO muscles and changes in length of the TrA muscle (measured as lateral displacement of the fascial insertion of the TrA muscle) there were consistent, clear changes in sonographic parameters, with incremental changes for contractions of less than 20% of maximal voluntary contraction (MVC).Clinical muscle testing of the TrA muscle has been based on its anatomical structure and horizontal fiber arrangement. Two muscle tests include observation of the abdominal wall during either a voluntary drawing-in of the abdominal wall 26 or by using automatic responses of the muscle to expiration.18 A relationship between the clinical muscle test and laboratory EMG measures of TrA muscle function has been demonstrated.14 In addition, the action of the bilateral muscle bellies of the TrA muscle has been viewed during the drawing-in maneuver using RUSI and magnetic resonance imaging (MRI). 8,9 In a recent study conducted on elite asymptomatic cricketers, 9 the muscle bellies of the TrA muscle were seen to thicken as well as shorten in length durt sTudy design: Test-retest intrarater reliability study.t oBJecTive: To examine reliability of abdominal musculature measurements across a broad range of conditions for a physical therapist newly trained in assessment using rehabilitative ultrasound imaging (RUSI).t BAckground: RUSI has previously been used to assess abdominal muscle function during a drawing-in maneuver of the anterior abdominal wall, and measurements conducted by an experienced assessor have been validated by comparison with magnetic resonance imaging. Few studies have examined the reliability of less experienced operators, and only in isolated measurement conditions. t MeTHods And MeAsures: Nineteen subjects (11 female, 8 male) without a history of low back pain performed the abdominal drawing-in maneuver in a supine hook-lying position. RUSI was used bilaterally to assess the thickness of the internal oblique (IO) and transversus abdominis (TrA) muscles at rest and on contraction, as well as changes in the length of the TrA muscle (indicated by slide of the anterior abdominal fascia). The reliability of a novice rater who received 8 hours of training was examined (a) across 3 measurements of the same ultrasound image, (b) across 3 separate ultrasound images (averaged for days and sides of abdomen), and (c) ac...

Reliability of real-time ultrasound measurement of transversus abdominis thickness in healthy trained subjects

“…No significant increase of ICC was registered after introducing a third repeated measurement. These findings are consistent with previous studies [6][7][8][9][10][11][12][13][14][16][17][18][19][20][21][22].…”

“…These parameters are regarded quick and easy to obtain, non-invasive indicators of the TrA performance which is crucial for stability and control of the lumbar spine [2,3]. Authors conclude that US measurement of TrA thickness generally shows acceptable reliability in healthy persons [6][7][8][9][10][11][12][13][14][15][16] and patients with low back pain [12,[17][18][19][20][21][22]. Results concerning TrA thickness change are still contradictory or unclear.…”

Test-Retest and Intrarater Reliability of 2-Dimensional Ultrasound Measurements of Distance Between Rectus Abdominis in Women

“…Across-day reliability may be of interest to physiotherapists who perform repeated assessments of abdominal muscle function over time, 16 and factors such as relocation of the original imaging site and reproduction of the same transducer pressure and orientation, as well as maintenance of these factors during muscle contraction, could adversely affect reliability. 16 The aims of the present study were to evaluate test-retest and intrarater reliability of 2-dimensional ultrasound imaging of the IRD at rest and during abdominal crunch and drawing-in exercises, and to verify the differences in IRD related to the postpartum condition.…”

The effect of food consumption on the thickness of abdominal muscles, employing ultrasound measurements

“…Several studies have reported good reliability for measurement of individual abdominal muscle thicknesses at rest or in contracted state [10,11,18,30]. Also ultrasonic biofeedback is used to teach TrA contraction in patients with LBP [2,3,23].…”