title: Measurement of plantarflexor spasticity in traumatic brain injury: correlational study of resistance torque compared with the modified Ashworth scale.
abstract: OBJECTIVE
  To examine the usefulness of a biomechanical measure, resistance torque (RT), in quantifying spasticity by comparing its use with a clinical scale, the modified Ashworth scale (MAS), and quantitative electrophysiological measures.
  
  
  METHODS
  This is a correlational study of spasticity measurements in 34 adults with traumatic brain injury and plantarflexor spasticity. Plantarflexor spasticity was measured in the seated position before and after cryotherapy using the MAS and also by strapping each subject's foot and ankle to an apparatus that provided a ramp and hold stretch. The quantitative measures were (1) reflex threshold angle (RTA) calculated through electromyographic signals and joint angle traces, (2) Hdorsiflexion (Hdf)/Hcontrol (Hctrl) amplitude ratio obtained through reciprocal inhibition of the soleus H-reflex, (3) Hvibration (Hvib)/Hctrl ratio obtained through vibratory inhibition of the soleus H-reflex, and (4) RT calculated as the time integral of the torque graph between the starting and ending pulses of the stretch.
  
  
  RESULTS
  Correlation coefficients between RT and MAS scores in both pre-ice (0.41) and post-ice trials (0.42) were fair (P = 0.001). The correlation coefficients between RT scores and RTA scores in both the pre-ice (0.66) and post-ice trials (0.75) were moderate (P <or= 0.001).
  
  
  CONCLUSIONS
  RT is a measure of the cumulative torque during an imposed stretch. The MAS is a subjective measure of the cumulative resistance perceived by the clinician during an imposed stretch. RT seems to be a fair quantitative correlate of the MAS in assessing spasticity.
authors: Spine Section PM & R Service, Dallas VA Medical Center, Dallas Texas 75216, USA.
authors: Thiru
authors: T
authors: Annaswamy
authors: Srinivas
authors: S
authors: Mallempati
authors: Stephen C
authors: SC
authors: Allison
authors: Lawrence D
authors: LD
authors: Abraham
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D001930:Brain Injuries / Q000145:classification* / Q000534:rehabilitation; D017679:Cryotherapy; D004594:Electrophysiology; D006801:Humans; D009128:Muscle Spasticity / Q000145:classification* / Q000628:therapy; D019415:Torque