title: Assessment of quadriceps muscle inactivation with a new electrical stimulation paradigm.
abstract: BACKGROUND
  In this study we evaluated the validity of garment-based quadriceps stimulation (GQS) for assessment of muscle inactivation in comparison with femoral nerve stimulation (FNS).
  
  
  METHODS
  Inactivation estimates (superimposed doublet torque), self-reported discomfort, and twitch and doublet contractile properties were compared between GQS and FNS in 15 healthy subjects.
  
  
  RESULTS
  Superimposed doublet torque was significantly lower for GQS than for FNS at 20% and 40% maximum voluntary contraction (MVC) (P < 0.01), but not at 60%, 80%, and 100% MVC. Discomfort scores were systematically lower for GQS than for FNS (P < 0.05). Resting twitch and doublet peak torque were lower for GQS, and time to peak torque was shorter for GQS than for FNS (P < 0.01).
  
  
  CONCLUSIONS
  GQS can be used with confidence for straightforward evaluation of quadriceps muscle inactivation, whereas its validity for assessment of contractile properties remains to be determined.
authors.affiliation: Neuromuscular Research Laboratory, Schulthess Clinic, Lengghalde 2, 8008, Zurich, Switzerland.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Wellauer
authors.forename: Claudia
authors.initials: C
authors.lastname: Morf
authors.forename: Marco A
authors.initials: MA
authors.lastname: Minetto
authors.forename: Nicolas
authors.initials: N
authors.lastname: Place
authors.forename: Nicola A
authors.initials: NA
authors.lastname: Maffiuletti
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D055592:Biophysical Phenomena / Q000502:physiology*; D004558:Electric Stimulation; D004576:Electromyography; D015444:Exercise; D005260:Female; D005267:Femoral Nerve / Q000502:physiology; D006801:Humans; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*; D058748:Pain Perception / Q000502:physiology; D052097:Quadriceps Muscle / Q000502:physiology*; D055070:Resistance Training; D019415:Torque; D055815:Young Adult
keywords: activation; contractility; discomfort; quadriceps; twitch interpolation