title: Mechanics of ambulation with standard and spring-loaded crutches.
abstract: OBJECTIVE
  To compare kinetic measures and spatiotemporal variables assessed during walking with standard axillary crutches and spring-loaded crutches.
  
  
  METHODS
  A repeated-measures design in which healthy subjects walked with both standard and spring-loaded crutches.
  
  
  METHODS
  Biomechanics research laboratory.
  
  
  METHODS
  Ten healthy young adult volunteers participated. Only female volunteers between 154.9 and 175.3 cm in stature were selected to fit the size of the crutches used.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  The main outcome measures were kinetic variables such as ground reaction force, rate of force rise, and impulse and spatiotemporal variables such as stride length, stride time, and percentage of stride spent in stance.
  
  
  RESULTS
  The rate of ground reaction force rise and impulse of the ground reaction force (both P<.001) were reduced by 33% and 13% to 26%, respectively, but the peak ground reaction force was slightly greater (P=.001) with spring-loaded crutches. The stride time was increased with spring-loaded crutches (P=.005), but the stride length did not differ significantly (P=.465).
  
  
  CONCLUSIONS
  The use of spring-loaded crutches altered the mechanics of crutch gait in ways that are likely to reduce overuse injury in crutch users. Further study of spring-loaded crutches is warranted, especially with respect to their energetic efficiency.
authors.affiliation: Department of Kinesiology, The Pennsylvania State University, University Park, PA 16802, USA.
authors.forename: Adriana
authors.initials: A
authors.lastname: Segura
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Piazza
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D003446:Crutches; D004185:Disability Evaluation; D004867:Equipment Design; D005081:Exercise Therapy / Q000295:instrumentation*; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D007866:Leg / Q000502:physiology*; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D012016:Reference Values; D016138:Walking / Q000502:physiology*