title: The effect of orthotics on intersegmental foot kinematics and the EMG activity of select lower leg muscles.
abstract: BACKGROUND
  Persons with exertional related leg pain are managed using orthoses. This study aimed to determine the effectiveness of two orthoses in altering foot motion and muscle activity in symptomatic individuals.
  
  
  METHODS
  52 subjects with lower extremity pain complaints of a non-traumatic, mechanical origin received one of two orthoses. Foot kinematics and EMG activity were recorded while treadmill walking in 3 footwear conditions. The peak EMG activity of the sandal and sandal orthotic trials (normalized to peak barefoot values) and foot motion during 4 subphases of stance were obtained. Using a multivariate multilevel model via linear mixed models, the effect of orthoses within these phases on motion and EMG was determined.
  
  
  RESULTS
  An effect of orthotic type was not present for any of the rearfoot or forefoot motions (p>.10). A significant effect of footwear and orthotic type on first ray motion (p<.05) during subphases 2 and 4 was seen. During subphase 4 an interaction effect between footwear condition and orthotic type on tibialis posterior EMG activity (p=.036) was present.
  
  
  CONCLUSIONS
  Orthoses are unable to control rear or midfoot motion but appear to control first ray motion and during late stance, affect tibialis posterior muscle activity. Public trials registry number: NCRT02143947.
authors.affiliation: Motion Analysis Laboratory, Quinnipiac University, Hamden, CT, United States; Department of Physical Therapy, Quinnipiac University, Hamden, CT, United States. Electronic address: juan.garbalosa@quinnipiac.edu.
authors.forename: Juan C
authors.initials: JC
authors.lastname: Garbalosa
authors.affiliation: Motion Analysis Laboratory, Quinnipiac University, Hamden, CT, United States.
authors.forename: Bruce
authors.initials: B
authors.lastname: Elliott
authors.affiliation: Frank H Netter, MD, School of Medicine, Quinnipiac University, Hamden, CT, United States.
authors.forename: Richard
authors.initials: R
authors.lastname: Feinn
authors.affiliation: Motion Analysis Laboratory, Quinnipiac University, Hamden, CT, United States; Department of Physical Therapy, Quinnipiac University, Hamden, CT, United States.
authors.forename: Ryan
authors.initials: R
authors.lastname: Wedge
mesh_terms: D001696:Biomechanical Phenomena; D004576:Electromyography; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D005545:Forefoot, Human / Q000503:physiopathology*; D005684:Gait / Q000502:physiology*; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*; D009989:Orthotic Devices; D010146:Pain / Q000503:physiopathology / Q000534:rehabilitation*; D016138:Walking / Q000502:physiology*; D055815:Young Adult
keywords: Biomechanics; EMG; Gait; Orthotics