An investigation into the inter-rater reliability of ultrasound imaging of abdominal muscles in adults

  • Fiona Alston
  • Carmen Britz
  • Tarryn Du Preez
  • Sandile Mthembu
  • Chrissie Pavon
  • Natasha Pells
  • Martin Sarembock
  • Janeen Hughes
  • Jennifer Jelsma

Abstract

Background:
Ultrasound imaging is a non-invasive tool that could be useful in observation of bodily structures, diagnostic purposes, bio-feedback and as an outcome measure. As core stability has become a focal point in rehabilitation, the ability to observe the muscles involved could prove to be clinically useful.

Aim:
This study was therefore conducted to determine the inter-rater reliability of the ultrasound imaging machine.

Methods:
Rectus Abdominus (RA), External Obliquus (EO), Internal Obliquus (IO) and Transversus Abdominus (TrA) were imaged in both a relaxed and a contracted condition. Fifty one participants of thirty years and older were recruited from visitors to a tertiary hospital. Two investigators independently measured the thickness of the abdominal muscles.

Results:
Generally there was a strong relationship when measuring RA, IO and EO, although strong contractions did not meet the criteria set for reliability. RA relaxed had the strongest correlation between raters (r=0.89, p<0.01) while IO oblique crunch (OC) showed the weakest correlation (r=0.58, p<0.01. A significant difference was found in thickness from the relaxed state
to measuring EO hollowing-in-manoeuvre (HI) (p=0.02), Oblique Crunch (p<0.01) and RA chin-to-chest (p<0.01). Generally, males showed a significantly larger muscle thickness compared to females and a
high Body Mass Index (BMI) was associated with unclear images (p<0.01).

Conclusion:
The use of the ultrasound imaging machine results in reliable measurement regarding the more superficial muscles in a state of relaxed or moderate activity, even when used by relatively inexperienced therapists. It is recommended that US can be used as a reliable outcome measure of most abdominal muscle activity.

References

Bemben, M.G. (2002). Use of diagnostic ultrasound for

assessing muscle size. Journal of Strength and Conditioning Research, 16(1): 103 – 108.

Bunce, S.M., Hough, A.D. and Moore, A.P. (2004).

Measurement of abdominal muscle thickness using M- mode ultrasound imaging during functional

activities. Manual Therapy, 9(1): 41 – 44.

Cholewicki, J. and van Vliet, J.J. (2001). Relative contribution of trunk muscles to the stability

of the lumbar spine during isometric exertions. Clinical Biomechanics, 17(2): 99-105.

Critchley, D.J. and Coutts, F.J. (2002). Abdominal muscle function in chronic low-back pain

patients: measurements with real-time ultrasound scanning. Physiotherapy, 86: 322–332.

Ferreira, H., Ferreira, M.L. and Hodges, P.W. (2004).

Changes in recruitment of the abdominal muscles in people with low back pain: Ultrasound

measurement of muscle activity. Spine, 29(22): 2560-2566.

Gray, H. (2002). Gray's Anatomy. Parragon. Bath, United Kingdom. p: 241 - 248.

Hides, J., Wilson, S., Stanton, W., McMahon, S., Keto, H., McMahon, K., Bryant, M. and Richardson, C. (2006). An MRI investigation into the function of the transverses abdominis muscle during “drawing in” of the abdominal wall. Spine, 31(6): 175-178.

Kiesel, K.B., Uhl, T., Underwood, F.B. and Nitz, A.J. (2006). Rehabilitative ultrasound measurement of select trunk muscle activation during induced pain. Manual Therapy, 13(2): 132-138.

Lwanga, S.K., Tye, C. and Ayeni, O. (1999). Teaching Health Statistics: Lesson and seminar outlines. World Health Organisation. Second edition. p: 14.

McMeeken, J.M., Bieth, I.D., Neham, D.J., Milligan, P.

and Critowly, D.J. (2004). The relationship between EMG and change in thickness of transversus

abdominis. Clinical Biomechanics, 19(4): 337-342.

Rankin, G., Stokes, M. and Newman, D.J. (2006).

Abdominal muscle size and symmetry in normal subjects. Muscle Nerve, 34: 230-236.

Sherburn, M., Murphy, C.A., Carroll, S., Allen, T.J. and Galea, M.P. (2005). Investigation of

transabdominal real-time ultrasound to visualise the muscles of the pelvic floor. Australian

Journal of Physiotherapy, 51: 167-170.

Teyhen, D.S., Miltenberger, C.E., Deiters, H.M., Del Toro, Y.M., Pulliam, J.N., Childs, J.D.,

Boyles, R.E. and Flynn, T.W. (2005). The use of ultrasound imaging of the abdominal drawing-in

manoeuvre in subjects with low back pain. Journal of Orthopaedic and Sports Physical Therapy, 35:

-355.

Urquhart, D.M., Barker, P.J., Hodges, P.W., Story, I.H. and Briggs, C.A. (2004). Regional morphology of the transversus abdominis and obliquus internus and externus abdominis muscles. Clinical Biomechanics, 20: 233-241.

Watanabe, K., Miyamoto, K., Masuda, T. and Shinizu, K. (2004). Use of Ultrasonography to Evaluate of the Erector Spinae Muscle in Maximum Flexion and Extension of the Lumbar Spine. Spine, 29(13): 1472- 1477.

Whittaker, J. (2004). Abdominal ultrasound imaging of pelvic floor muscle function in individuals with low back pain. The Journal of Manual & Manipulative Therapy, 12(1): 44-49.

Whittaker, J. (2006). Current Perspectives: The clinical application of ultrasound imaging by physical therapists. The Journal of Manual & Manipulative Therapy, 14(2), Guest Editorial: 73-75.

Whittaker, J.L. (2007). Ultrasound imaging of the lateral abdominal wall muscles in individuals with lumbopelvic pain and signs of concurrent hypocapnia. Manual Therapy, 13(5): 404-410.

Wink, M.H., Wijkstra, H., De La Rosette, J.J. and

Grimbergen, C.A. (2006). Review article – Ultrasound imaging and contrast agents: A safe alternative to MRI?, Minimally Invasive Therapy and Allied Technologies, 15(2): 93-100.

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