title: Effects of length on the catchlike property of human quadriceps femoris muscle.
abstract: OBJECTIVE
  Recent reports have suggested that electrical stimulation trains that take advantage of the catchlike property of skeletal muscle can produce higher forces from skeletal muscle than traditionally used constant-frequency trains. This study investigated the effects of catchlike-inducing trains on human quadriceps femoris muscles while the kneejoint was held at 15 degrees of flexion.
  
  
  METHODS
  Subjects (N=12) were tested with constant-frequency trains that had interpulse intervals ranging from 10 to 160 milliseconds and comparable catchlike-inducing trains. Data were collected during the control condition (1 train every 10 seconds) and during repetitive contractions (1 train per second).
  
  
  RESULTS
  During control and repetitive activation conditions, catchlike-inducing trains produced approximately 5% to 110% greater peak forces than comparable constant-frequency trains, depending on the frequencies being compared. Total forces produced (ie, force-time integrals) were increased up to 59% and 49% during the control and repetitive activation conditions, respectively.
  
  
  CONCLUSIONS
  These results support earlier findings that catchlike-inducing trains may be advantageous in functional electrical stimulation applications.
authors.affiliation: Interdisciplinary Graduate Program in Biomechanics and Movement Sciences, University of Delaware, Newark, USA.
authors.forename: S C
authors.initials: SC
authors.lastname: Lee
authors.forename: M L
authors.initials: ML
authors.lastname: Gerdom
authors.forename: S A
authors.initials: SA
authors.lastname: Binder-Macleod
mesh_terms: D000328:Adult; D004558:Electric Stimulation / Q000379:methods*; D005260:Female; D006801:Humans; D007717:Knee / Q000502:physiology*; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*; D013997:Time Factors