title: Surface electromyographic analysis of core trunk and hip muscles during selected rehabilitation exercises in the side-bridge to neutral spine position.
abstract: BACKGROUND
  Strengthening of core hip, trunk, and abdominal muscles has been utilized with injury prevention and low back pain and has the potential to improve athletic performance.
  
  
  OBJECTIVE
  During a side-bridge, trunk and thigh muscles on the ipsilateral weightbearing side would produce greater activation than their counterparts on the contralateral nonweightbearing side.
  
  
  METHODS
  Descriptive laboratory study.
  
  
  METHODS
  Twelve females and 13 males participated. Electromyography (EMG) signals were gathered for 5 right-sided muscles (rectus abdominis [RA], external oblique [EO], longissimus thoracis [LT], lumbar multifidus [LM], and gluteus medius [GM]) during 3 repetitions of 4 side-bridging exercises (trunk-elevated side support [TESS], foot-elevated side support [FESS], clamshell, and rotational side-bridge [RSB]) performed bilaterally in random order using surface electrodes. EMG signals were normalized to peak activity in maximum voluntary isometric contraction (MVIC) trials and expressed as a percentage. Descriptive EMG data were calculated for EMG recruitment (% MVIC) and compared between right side up and right side down conditions and between exercises with 2-way repeated-measures analyses of variance at α = 0.05.
  
  
  RESULTS
  RSB created the most muscle activation in 3 of 4 recorded trunk muscles (RA, 43.9% MVIC; EO, 62.8 % MVIC; and LT, 41.3% MVIC). Activation of the GM exceeded 69% MVIC for TESS, FESS, and RSB. With the exception of the RA in RSB and LT in TESS, recruitment within muscles of the ipsilateral weightbearing trunk and thigh (% MVIC) was significantly greater than their counterparts on the nonweightbearing trunk and thigh for all muscles during the side-bridge exercise conditions.
  
  
  CONCLUSIONS
  Muscle recruitment was greater within muscles of the ipsilateral weightbearing trunk and thigh for all examined muscles except RA during RSB and LT during TESS. Activation at or above 50% MVIC is needed for strengthening. Activation of the GM and EO meets these requirements.
  
  
  CONCLUSIONS
  Side-bridge exercises appear to provide strengthening benefits to core hip, trunk, and abdominal muscles on the ipsilateral weightbearing side.
authors.affiliation: Mayo Clinic College of Medicine, Rochester, Minnesota.
authors.forename: James W
authors.initials: JW
authors.lastname: Youdas
authors.affiliation: Mayo Clinic College of Medicine, Rochester, Minnesota.
authors.forename: Mallory M P
authors.initials: MM
authors.lastname: Boor
authors.affiliation: Mayo Clinic College of Medicine, Rochester, Minnesota.
authors.forename: Arynn L
authors.initials: AL
authors.lastname: Darfler
authors.affiliation: Mayo Clinic College of Medicine, Rochester, Minnesota.
authors.forename: Margaret K
authors.initials: MK
authors.lastname: Koenig
authors.affiliation: Mayo Clinic College of Medicine, Rochester, Minnesota.
authors.forename: Katherine M
authors.initials: KM
authors.lastname: Mills
authors.affiliation: Mayo Clinic College of Medicine, Rochester, Minnesota.
authors.forename: John H
authors.initials: JH
authors.lastname: Hollman
keywords: core musculature; electromyography; side plank; therapeutic exercises