title: Loads on the uprights of a knee-ankle-foot orthosis.
abstract: BACKGROUND
  Objective design criteria for orthotic components is lacking. This paucity of data results in prescription guidelines based on assumptions or practitioners' past experience, and the potential for incorrectly designed components. The purpose of this study was to directly measure loads on the knee joint of a knee-ankle-foot orthosis.
  
  
  METHODS
  Case series.
  
  
  METHODS
  Three subjects who had been prescribed a knee-ankle-foot orthosis for quadriceps weakness underwent gait analysis and orthotic upright load data collection. A load sensor to measure the three force and three moment components was used in place of the lateral knee joint while the subjects walked in three knee flexion positions.
  
  
  RESULTS
  Forces were highest in compression and moments were greatest in the sagittal plane. The kinetics did not increase solely with patient weight. There was substantial variability between subjects.
  
  
  CONCLUSIONS
  This data will help guide orthotic component design and prescription guidelines. Knowledge of loading conditions will lead to more optimal orthotic intervention for patients and increased patient satisfaction.
  
  
  CONCLUSIONS
  This study is one of the first to directly measure loads on the upright of a KAFO. These data provide objective targets for engineering design. The data from this small case series can also be used to establish guidelines for patient device selection.
authors.affiliation: Motion Analysis Laboratory, Mayo Clinic, Rochester, MN 55905, USA.
authors.forename: K A
authors.initials: KA
authors.lastname: Bernhardt
authors.forename: K R
authors.initials: KR
authors.lastname: Kaufman
mesh_terms: D000843:Ankle Joint / Q000502:physiology*; D004867:Equipment Design; D005260:Female; D005528:Foot / Q000502:physiology; D005684:Gait / Q000502:physiology; D006801:Humans; D007719:Knee Joint / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D018908:Muscle Weakness / Q000503:physiopathology / Q000534:rehabilitation / Q000628:therapy; D009989:Orthotic Devices; D052097:Quadriceps Muscle / Q000502:physiology; D016474:Weight-Bearing / Q000502:physiology*