title: Core muscle activity in a series of balance exercises with different stability conditions.
abstract: Literature that provides progression models based on core muscle activity and postural manipulations is scarce. The purpose of this study was to investigate the core muscle activity in a series of balance exercises with different stability levels and additional elastic resistance. A descriptive study of electromyography (EMG) was performed with forty-four healthy subjects that completed 12 exercises in a random order. Exercises were performed unipedally or bipedally with or without elastic tubing as resistance on various unstable (uncontrolled multiaxial and uniaxial movement) and stable surfaces. Surface EMG on the lumbar multífidus spinae (LM), thoracic multífidus spinae (TM), lumbar erector spinae (LE), thoracic erector spinae (TE) and gluteus maximus (GM), on the dominant side of the body were collected to quantify the amount of muscle activity and were expressed as a % of the maximum voluntary isometric contraction (MVIC). Significant differences (p<.001) were found between exercises. The three unipedal standing exercises with additional elastic resistance generated the greatest EMG values, ranging from 19% MVIC to 30% MVIC. Postural manipulations with additional elastic resistance and/or unstable devices increase core muscle activity. An adequate exercise progression based on global core EMG could start with seated positions, progressing to bipedal standing stance (i.e., from either multiaxial or stable surface to uniaxial surface). Following this, unipedal standing positions may be performed (i.e., from either multiaxial or stable surface to uniaxial surface) and finally, elastic resistance must be added in order to increase EMG levels (i.e., from stable surface progressing to any of the used unstable surfaces).
authors.affiliation: Research Group in Sport and Health, Department of Physical Education and Sports, University of Valencia, Valencia, Spain.
authors.forename: Joaquin
authors.initials: J
authors.lastname: Calatayud
authors.affiliation: Research Group in Sport and Health, Department of Physical Education and Sports, University of Valencia, Valencia, Spain.
authors.forename: Sebastien
authors.initials: S
authors.lastname: Borreani
authors.affiliation: University Institute of Science in Physical Activity and Sports, Catholic University of Valencia, Valencia, Spain.
authors.forename: Julio
authors.initials: J
authors.lastname: Martin
authors.affiliation: Research Group in Sport and Health, Department of Physical Education and Sports, University of Valencia, Valencia, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Martin
authors.affiliation: Austral University of Chile, Faculty of Pedagogy in Physical Education, Sports and Recreation, Valdivia, Chile.
authors.forename: Jorge
authors.initials: J
authors.lastname: Flandez
authors.affiliation: Research Group in Sport and Health, Department of Physical Education and Sports, University of Valencia, Valencia, Spain. Electronic address: juan.colado@uv.es.
authors.forename: Juan C
authors.initials: JC
authors.lastname: Colado
mesh_terms: D000328:Adult; D004576:Electromyography; D005260:Female; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D008297:Male; D004856:Postural Balance / Q000502:physiology*; D011187:Posture / Q000502:physiology; D055070:Resistance Training; D013848:Thigh / Q000502:physiology; D016474:Weight-Bearing / Q000502:physiology*; D055815:Young Adult
keywords: EMG; Instability; Resistance training; Stability; Trunk