Effects of a Core Strengthening Program on Muscle Activity Patterns, Strength, and Endurance in People with and without a History of Low Back Pain: A Randomized Controlled Trial

Gillian L. Hatfield


Background of Study: Altered patterns of abdominal and low back muscle activity have been reported in people in the sub-acute phase of low back injury. Specifically, higher overall muscle activity and less ability to match activity to task demands have been found. Objective: This study determined if an 8-week group exercise intervention would alter muscle activity, strength, and endurance in people with/without a history of low back pain (LBP). Method: In this randomized controlled trial 46 participants (age 19-55) with a history of LBP were randomized to exercise (LBPEx, n=24) and no-exercise (LBPCon, n=22) groups. 27 participants without a history of LBP (NoLBP) also exercised. 17 LBPEx and 19 NoLBP participants completed the intervention. 19 LBPCon were tested at 8-week follow-up. The exercise intervention was an 8-week, choreographed, 30-minute group exercise intervention (Les Mills CoreTM) focused on building core strength, stability, and endurance. Pre and post-intervention surface electromyograms from abdominal and low back muscles were recorded during a trunk stability task (TST), and analyzed using Principal Component Analysis to extract patterns corresponding to overall amplitude and relative activation during the TST loading phase. Abdominal and back extensor strength and endurance were also measured. Results: It was found that overall abdominal activity decreased for left anterior external oblique (p=0.019 for TST level 3), left lateral external oblique (p=0.012 for TST level 3), and right posterior external oblique (p=0.035 for TST level 3) in LBPEx and for right lateral external oblique (p=0.009 for TST level 2 and p=0.004 for TST level 3) and left posterior external oblique (p=0.014 for TST level 2 and p=0.011 for TST level 3) in NoLBP during the TST. Abdominal strength and endurance, and back extensor endurance increased for LBPEx and NoLBP (p<0.05). Back extensor strength increased for NoLBP (p<0.05). Relative abdominal activation during the TST level 2 loading phase increased for right upper rectus abdominus (p=0.05), right lateral external oblique (p=0.002), and left posterior external oblique (p=0.006) for NoLBP, and for left anterior external oblique (p=0.042) for LBPEx. Conclusion: Les Mills CoreTM is readily available and may be recommended as a safe, accessible, and effective intervention to increase abdominal strength and endurance, and back extensor endurance, even for people with a history of LBP.


Low Back Pain, Electromyography, Exercise, Principal Component Analysis, Muscles, Core Stability

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American College of Sports Medicine. (2010). ACSM's Guidelines for Exercise Testing and Prescription (8th Edition). (W. Thompson, Ed.) Philadelphia, PA: Lippincott, Williams & Wilkins.

Butler, H. L., Hubley-Kozey, C. L., & Kozey, J. W. (2013). Changes in electromyographic activity of trunk muscles within the sub-acute phase for individuals deemed recovered from a low back injury. Journal of Electromyography and Kinesiology, 23, 369-77. https://doi.org/10.1016/j.jelekin.2012.10.012

Calatayud, J., Escriche-Escuder, A., Cruz-Montecinos, C., Andersen, L. L., Pérez-Alenda, S., Aiguadé, R., &

Casaña, J. (2019). Tolerability and Muscle Activity of Core Muscle Exercises in Chronic Low-back Pain. International journal of environmental research and public health, 16(19), 3509. https://doi.org/10.3390/ijerph16193509

Clarke Davidson, K. L., & Hubley-Kozey, C. L. (2005). Trunk Muscle Responses to Demands of an Exercise Progression to Improve Dynamic Spinal Stability. Archives of Physical Medicine & Rehabilitation, 86, 216-23. https://doi.org/10.1016/j.apmr.2004.04.029

Faul, F., Erdfelder, E., Lang, A.-G., & Buchner, A. (2007). G*Power 3: A flexible statistical power analysis

program for the social, behavioral, and biomedical sciences. Behavior Research Methods, 39, 175-191. https://doi.org/10.3758/bf03193146

Hayden , J. A., Ellis, J., Ogilvie, R., Stewart , S. A., Bagg, M. K., Stanojevic, S., . . . Saragiotto, B. T. (2021). Some types of exercise are more effective than others in people with chronic low back pain: a network meta-analysis. Journal of Physiotherapy, 67(4), 252-262. https://doi.org/10.1016/j.jphys.2021.09.004

Hestbaek, L., Leboeuf-Yde, C., & Manniche, C. (2003). Low back pain: what is the long-term course? A review of studies of general patient populations. European Spine Journal, 12(2), 149-65. https://doi.org/10.1007/s00586-002-0508-5

Hlaing, S. S., Puntumetakul, R., Khine, E. E., & Boucaut, R. (2021). Effects of core stabilization exercise and

strengthening exercise on proprioception, balance, muscle thickness and pain related outcomes in patients with subacute nonspecific low back pain: a randomized controlled trial. BMC musculoskeletal disorders, 22(1), 998. https://doi.org/10.1186/s12891-021-04858-6

Hoy, D., Brooks, P., Blyth, F., & Buchbinder, R. (2010). The Epidemiology of low back pain. Best Practice & Research: Clinical Rheumatology, 24(6), 769-81. https://doi.org/10.1016/j.berh.2010.10.002

Hubley-Kozey, C. L., & Vezina, M. J. (2002a). Muscle activation during exercises to improve trunk stability in men

with low back pain. Archives of Physical Medicine Rehabilitation, 83, 1100-8. https://doi.org/10.1053/apmr.2002.33063

Hubley-Kozey, C. L., & Vezina, M. J. (2002b). Differentiating temporal electromyographic waveforms between those with chronic low back pain and healthy controls. Clinical Biomechanics, 17, 621-9. https://doi.org/10.1016/s0268-0033(02)00103-1

Hubley-Kozey, C. L., Hanada, E. Y., Gordon, S., Kozey, J. W., & McKeon, M. (2009). Differences in Abdominal Muscle Activation Patterns of Younger and Older Adults Performing an Asymmetric Leg-Loading Task. Physical Medicine & Rehabilitation, 1(11), 1004-13. https://doi.org/10.1016/j.pmrj.2009.09.018

Hubley-Kozey, C. L., Hatfield, G. L., & Clarke Davidson, K. (2010). Temporal co-activation of abdominal muscles during dynamic stability exercises. Journal of Strength and Conditioning Research, 24(5), 1246-55. https://doi.org/10.1519/JSC.0b013e3181ce24c7

Manchikanti, L. (2000). Epidemiology of Low Back Pain. Pain Physician, 3(2), 167-92.

Moreside, J. M., Quirk, D. A., & Hubley-Kozey, C. L. (2014). Temporal Patterns of the Trunk Muscles Remain Altered in a Low Back Injured Population Despite Subjective Reports of Recovery. Archives of Physical Medicine and Rehabilitation, 95, 686-98. https://doi.org/10.1016/j.apmr.2013.10.003

Roland, M., & Morris, R. (1983). A study of the natural history of back pain. Part I: development of a reliable and sensitive measure of disability in low-back pain. Spine, 8(2), 141-4. https://doi.org/10.1097/00007632-198303000-00004

Waburton, D., Jamni, V., Bredin , S., & Gledhill, N. (2011). The Physical Activity Readiness Questionnaires for Everyone (PAR-Q+) and Electronic Physical Activity Readiness Medical Examination (ePARmed-X+). . Health & Fitness Journal of Canada, 4(2), 3-23. https://doi.org/10.14288/hfjc.v4i2.103

Yorks, D. M., Frothingham, C. A., & Schuenke, M. D. (2017). Effects of Group Fitness Classes on Stress and Quality of Life of Medical Students. The Journal of the American Osteopathic Association, 117(11), e17-e25. https://doi.org/10.7556/jaoa.2017.140

DOI: https://doi.org/10.7575/aiac.ijkss.v.10n.3p.37


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