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Reliability and validity of pendulum test measures of spasticity obtained with the Polhemus tracking system from patients with chronic stroke.

Bohannon RW, Harrison S, Kinsella-Shaw J - J Neuroeng Rehabil (2009)

Bottom Line: 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.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Physical Therapy, Neag School of Education, University of Connecticut, Storrs, USA. richard.bohannon@uconn.edu

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.

Conclusion: 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.

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Representative pendulum test tracing with angle of first reversal identified (large trace) and area under curve highlighted (small insert).
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Figure 2: Representative pendulum test tracing with angle of first reversal identified (large trace) and area under curve highlighted (small insert).

Mentions: The pendulum test was conducted while subjects were supine on a padded table with their nontested leg supported. The test employed the Polhemus Liberty magnetic position tracking system. Two sensors were positioned on the tested lower limb, one laterally over the knee axis of rotation and one just distal to the lateral malleolus (Figure 1). The system transmitter was placed in close proximity on the floor. After checking calibration of the field sensors, the tested leg was passively elevated to horizontal by one of the investigators. Once relaxation was assured by palpation of the patellar tendon, free mobilization of the patella and slight hefts and releases of the leg, data capture was initiated and the leg was dropped. Data capture ended when the leg ceased swinging. This procedure was completed, in random order, twice without a cuff weight at the ankle and twice with a cuff weight (5 lb/2.27 kg) at the ankle. After all subjects were tested, files were imported to Matlab for characterization of pendular kinematics. Characterization consisted of three measures (Figure 2): 1) First angle of reversal, when leg motion first switched from flexion to extension, 2) Area under the curve, the area between the knee angle during oscillations and resting angle, and 3) Velocity to first reversal, the change in knee angle between starting position and first reversal divided by time to first reversal.


Reliability and validity of pendulum test measures of spasticity obtained with the Polhemus tracking system from patients with chronic stroke.

Bohannon RW, Harrison S, Kinsella-Shaw J - J Neuroeng Rehabil (2009)

Representative pendulum test tracing with angle of first reversal identified (large trace) and area under curve highlighted (small insert).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2724410&req=5

Figure 2: Representative pendulum test tracing with angle of first reversal identified (large trace) and area under curve highlighted (small insert).
Mentions: The pendulum test was conducted while subjects were supine on a padded table with their nontested leg supported. The test employed the Polhemus Liberty magnetic position tracking system. Two sensors were positioned on the tested lower limb, one laterally over the knee axis of rotation and one just distal to the lateral malleolus (Figure 1). The system transmitter was placed in close proximity on the floor. After checking calibration of the field sensors, the tested leg was passively elevated to horizontal by one of the investigators. Once relaxation was assured by palpation of the patellar tendon, free mobilization of the patella and slight hefts and releases of the leg, data capture was initiated and the leg was dropped. Data capture ended when the leg ceased swinging. This procedure was completed, in random order, twice without a cuff weight at the ankle and twice with a cuff weight (5 lb/2.27 kg) at the ankle. After all subjects were tested, files were imported to Matlab for characterization of pendular kinematics. Characterization consisted of three measures (Figure 2): 1) First angle of reversal, when leg motion first switched from flexion to extension, 2) Area under the curve, the area between the knee angle during oscillations and resting angle, and 3) Velocity to first reversal, the change in knee angle between starting position and first reversal divided by time to first reversal.

Bottom Line: 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.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Physical Therapy, Neag School of Education, University of Connecticut, Storrs, USA. richard.bohannon@uconn.edu

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.

Conclusion: 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.

Show MeSH
Related in: MedlinePlus