title: Skeletal muscle contraction in healthy volunteers: assessment with Doppler tissue imaging.
abstract: OBJECTIVE
  To evaluate Doppler tissue imaging (DTI) in the measurement and characterization of skeletal muscle movement and contraction.
  
  
  METHODS
  Five healthy male subjects were examined with a commercially available ultrasound imaging unit modified for DTI. Velocities of the rectus femoris and gastrocnemius-soleus muscle motion were measured during the patellar and ankle reflexes, respectively. Velocity profiles were analyzed after digitization of the DTI images. Time to peak velocity, velocity range, and relaxation time were examined in each case over three contractions. For reflex contractions, reproducibility was examined by determining the latency period, area under the velocity curve, and duration of contraction for each of five consecutive reflexes.
  
  
  RESULTS
  Isotonic muscle contraction could be distinguished from passive movement by a higher tissue velocity range, by a more rapid initial acceleration slope, and by the velocity differential across the muscle. The intensity and duration of the contraction and plateau and relaxation phases of isotonic contraction could be measured in all muscle groups.
  
  
  CONCLUSIONS
  DTI provides detailed information about the dynamics of skeletal muscle contraction.
authors.affiliation: Department of Cardiology, Royal Infirmary of Edinburgh, Scotland.
authors.forename: N R
authors.initials: NR
authors.lastname: Grubb
authors.forename: A
authors.initials: A
authors.lastname: Fleming
authors.forename: G R
authors.initials: GR
authors.lastname: Sutherland
authors.forename: K A
authors.initials: KA
authors.lastname: Fox
mesh_terms: D000328:Adult; D006801:Humans; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging* / Q000502:physiology*; D012026:Reflex, Stretch / Q000502:physiology; D015203:Reproducibility of Results; D018608:Ultrasonography, Doppler