title: Influence of prolonged static stretching on motor unit firing properties.
abstract: BACKGROUND
  The purpose of this study was to examine the influence of a stretching intervention on motor control strategy of the biceps brachii muscle.
  
  
  METHODS
  Ten men performed twelve 100-s passive static stretches of the biceps brachii. Before and after the intervention, isometric strength was tested during maximal voluntary contractions (MVCs) of the elbow flexors. Subjects also performed trapezoid isometric contractions at 30% and 70% of MVC. Surface electromyographic signals from the submaximal contractions were decomposed into individual motor unit action potential trains. Linear regression analysis was used to examine the relationship between motor unit mean firing rate and recruitment threshold.
  
  
  RESULTS
  The stretching intervention caused significant decreases in y-intercepts of the linear regression lines. In addition, linear slopes at both intensities remained unchanged.
  
  
  CONCLUSIONS
  Despite reduced motor unit firing rates following the stretches, the motor control scheme remained unchanged.
authors.affiliation: Biophysics Laboratory, Department of Health and Exercise Science, University of Oklahoma, 1401 Asp Avenue. Room 104, Norman, Oklahoma, USA, 73019.
authors.forename: Xin
authors.initials: X
authors.lastname: Ye
authors.affiliation: Biophysics Laboratory, Department of Health and Exercise Science, University of Oklahoma, 1401 Asp Avenue. Room 104, Norman, Oklahoma, USA, 73019.
authors.forename: Travis W
authors.initials: TW
authors.lastname: Beck
authors.affiliation: Biophysics Laboratory, Department of Health and Exercise Science, University of Oklahoma, 1401 Asp Avenue. Room 104, Norman, Oklahoma, USA, 73019.
authors.forename: Nathan P
authors.initials: NP
authors.lastname: Wages
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000328:Adult; D001132:Arm; D004576:Electromyography; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D016014:Linear Models; D008297:Male; D009046:Motor Neurons / Q000502:physiology*; D009119:Muscle Contraction / Q000502:physiology; D018485:Muscle Fibers, Skeletal / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology*; D052580:Muscle Stretching Exercises; D018482:Muscle, Skeletal / Q000502:physiology*; D011999:Recruitment, Neurophysiological / Q000502:physiology*; D055815:Young Adult
keywords: firing rate; motor unit; recruitment threshold; stretching; surface EMG decomposition