title: Effect of foot orthotics on quadriceps and gluteus medius electromyographic activity during selected exercises.
abstract: OBJECTIVE
  To compare electromyographic activity of the vastus medialis, vastus lateralis, and gluteus medius during functional activities in subjects with different foot types while wearing various off-the-shelf foot orthotics.
  
  
  METHODS
  Experimental, controlled; 3 foot-type groups (pes planus, pes cavus, pes rectus) each tested in 4 orthotic conditions while performing 3 different exercises.
  
  
  METHODS
  Laboratory.
  
  
  METHODS
  Thirty healthy young adults, 10 with each foot type.
  
  
  METHODS
  Four conditions: no orthotic, 7 degrees medial rearfoot post, 4 degrees lateral rearfoot post, and neutral rearfoot post.
  
  
  METHODS
  Surface electromyographic activity for the vastus medialis, vastus lateralis, and gluteus medius during single-leg squatting, lateral stepdown, and maximum vertical jump exercises.
  
  
  RESULTS
  Greater vastus medialis and gluteus medius activity was found with all 3 orthotic conditions, regardless of subject foot type, during the single-leg squat and lateral stepdown. Less vastus lateralis activity was found with the vertical jump with all orthotic conditions, again regardless of foot type.
  
  
  CONCLUSIONS
  During slow controlled exercises such as the single-leg squat and lateral stepdown, vastus medialis and gluteus medius activity may be enhanced with an off-the-shelf orthotic, regardless of posting or foot type. These same findings do not appear to carry over to a more explosive task such as the maximal vertical jump.
authors.affiliation: Kinesiology Program, University of Virginia, Charlottesville, VA 22904, USA. jhertel@virginia.edu
authors.forename: Jay
authors.initials: J
authors.lastname: Hertel
authors.forename: Brent R
authors.initials: BR
authors.lastname: Sloss
authors.forename: Jennifer E
authors.initials: JE
authors.lastname: Earl
mesh_terms: D000328:Adult; D002081:Buttocks; D004576:Electromyography; D015444:Exercise / Q000502:physiology*; D005260:Female; D005528:Foot; D005530:Foot Deformities / Q000503:physiopathology*; D006801:Humans; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D018482:Muscle, Skeletal / Q000503:physiopathology*; D009989:Orthotic Devices; D013848:Thigh; D016474:Weight-Bearing / Q000502:physiology