Core stabilization has been utilized for rehabilitation and prevention of lower limb musculoskeletal injuries. Previous studies showed that activation of the abdominal core muscles enhanced the hip muscle activity in hip extension and abduction exercises. However, the lack of the direct measurement and quantification of the activation level of the abdominal core muscles during the execution of the hip exercises affect the level of evidence to substantiate the proposed application of core exercises to promote training and rehabilitation outcome of the hip region. The aim of the present study was to examine the effects of abdominal core activation, which is monitored directly by surface electromyography (EMG), on hip muscle activation while performing different hip exercises, and to explore whether participant characteristics such as gender, physical activity level and contractile properties of muscles, which is assessed by tensiomyography (TMG), have confounding effect to the activation of hip muscles in enhanced core condition.
Surface EMG of bilateral internal obliques (IO), upper gluteus maximus (UGMax), lower gluteus maximus (LGMax), gluteus medius (GMed) and biceps femoris (BF) of dominant leg was recorded in 20 young healthy subjects while performing 3 hip exercises: Clam, side-lying hip abduction (HABD), and prone hip extension (PHE) in 2 conditions: natural core activation (NC) and enhanced core activation (CO). EMG signals normalized to percentage of maximal voluntary isometric contraction (%MVIC) were compared between two core conditions with the threshold of the enhanced abdominal core condition defined as >20%MVIC of IO.
Enhanced abdominal core activation has significantly promoted the activation level of GMed in all phases of clam exercise (P < 0.05), and UGMax in all phases of PHE exercise (P < 0.05), LGMax in eccentric phases of all 3 exercises (P < 0.05), and BF in all phases of all 3 exercises except the eccentric phase of PHE exercise (P < 0.05). The %MVIC of UGMax was significantly higher than that of LGMax in all phases of clam and HABD exercises under both CO and NC conditions (P < 0.001) while the %MVIC of LGMax was significantly higher than UGMax in concentric phase of PHE exercise under NC condition (P = 0.003). Gender, physical activity level and TMG parameters were not major covariates to activation of hip muscles under enhanced core condition.
Abdominal core activation enhances the hip muscles recruitment in Clam, HABD and PHE exercises, and this enhancement is correlated with higher physical activity and stiffer hip muscle. Our results suggest the potential application of abdominal core activation for lower limb rehabilitation since the increased activation of target hip muscles may enhance the therapeutic effects of hip strengthening exercises.
Azevedo DC, Lauria AC, Pereira ARS, Andrade GT, Ferreira ML, Ferreira PH, et al. Intraexaminer and interexaminer reliability of pressure biofeedback unit for assessing lumbopelvic stability during 6 lower limb movement tests. J Manip Physiol Ther. 2013;36(1):33–43. CrossRef
Vera-Garcia FJ, Brown SHM, Gray JR, McGill SM. Effects of different levels of torso coactivation on trunk muscular and kinematic responses to posteriorly applied sudden loads. Clin Biomech. 2006;21(5):443–55. CrossRef
Committee IPAQR. Guidelines for data processing and analysis of the International Physical Activity Questionnaire (IPAQ). Retrieved November. 2005;15:2010.
Ng JK, Kippers V, Richardson CA. Muscle fibre orientation of abdominal muscles and suggested surface EMG electrode positions. Electromyogr Clin Neurophysiol. 1998;38(1):51–8. PubMed
Kendall F, McCreary E, Provance P, Rodgers M, Romani W. Muscles: Testing and Function With Posture and Pain. Baltimore: Lippincott, Williams & Wilkins; 2005.
Hislop H, Montgomery J. Muscle Testing: Techniques of Manual Examination. Philadelphia: W.B. Saunders Co.; 2002.
Sidorkewicz N, Cambridge ED, McGill SM. Examining the effects of altering hip orientation on gluteus medius and tensor fascae latae interplay during common non-weight-bearing hip rehabilitation exercises. Clin Biomech. 2014;29(9):971–6. CrossRef
Presswood L, Cronin J, Keogh J, Whatman C. Gluteus medius: applied anatomy, dysfunction, assessment and progressive strengthening. Strength and Conditioning Journal. 2008;30(5):41–53. CrossRef
Little RJ, Rubin DB. Statistical analysis with missing data: John Wiley & Sons; 2014.
- The effects of therapeutic hip exercise with abdominal core activation on recruitment of the hip muscles
Mandy KY Chan
Ka Wai Chow
Alfred YS Lai
Noble KC Mak
Jason CH Sze
Sharon MH Tsang
- BioMed Central
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