title: Reliability and validity of pendulum test measures of spasticity obtained with the Polhemus tracking system from patients with chronic stroke.
abstract: BACKGROUND
  Spasticity is a common impairment accompanying stroke. Spasticity of the quadriceps femoris muscle can be quantified using the pendulum test. The measurement properties of pendular kinematics captured using a magnetic tracking system has not been studied among patients who have experienced a stroke. Therefore, this study describes the test-retest reliability and known groups and convergent validity of the pendulum test measures obtained with the Polhemus tracking system.
  
  
  METHODS
  Eight patients with chronic stroke underwent pendulum tests with their affected and unaffected lower limbs, with and without the addition of a 2.2 kg cuff weight at the ankle, using the Polhemus magnetic tracking system. Also measured bilaterally were knee resting angles, Ashworth scores (grades 0-4) of quadriceps femoris muscles, patellar tendon (knee jerk) reflexes (grades 0-4), and isometric knee extension force.
  
  
  RESULTS
  Three measures obtained from pendular traces of the affected side were reliable (intraclass correlation coefficient > or = .844). Known groups validity was confirmed by demonstration of a significant difference in the measurements between sides. Convergent validity was supported by correlations > or = .57 between pendulum test measures and other measures reflective of spasticity.
  
  
  CONCLUSIONS
  Pendulum test measures obtained with the Polhemus tracking system from the affected side of patients with stroke have good test-retest reliability and both known groups and convergent validity.
authors: Department of Physical Therapy, Neag School of Education, University of Connecticut, Storrs, USA. richard.bohannon@uconn.edu
authors: Richard W
authors: RW
authors: Bohannon
authors: Steven
authors: S
authors: Harrison
authors: Jeffrey
authors: J
authors: Kinsella-Shaw
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000843:Ankle Joint / Q000503:physiopathology; D001696:Biomechanical Phenomena; D002908:Chronic Disease; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology; D007866:Leg / Q000503:physiopathology; D008280:Magnetics / Q000295:instrumentation / Q000379:methods* / Q000592:standards*; D008297:Male; D008875:Middle Aged; D009128:Muscle Spasticity / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology*; D012026:Reflex, Stretch / Q000502:physiology; D015203:Reproducibility of Results; D020521:Stroke / Q000150:complications / Q000503:physiopathology; D016683:Supine Position / Q000502:physiology; D014743:Videotape Recording