Reliability of concentric and eccentric torque during isokinetic knee extension in post-stroke hemiparesis

Clin Biomech (Bristol, Avon). 2006 May;21(4):395-404. doi: 10.1016/j.clinbiomech.2005.11.004. Epub 2006 Jan 5.

Abstract

Background: Emerging evidence on the velocity-dependent nature of force impairment in post-stroke hemiparesis has emphasized the complexity of strength and motor performance assessments in this clinical population. The need to establish reliability and responsiveness of muscle performance measures across a broad range of concentric and eccentric movement speeds is therefore clear, as these metrics will provide benchmarks both for making clinical inference and evaluating meaningful clinical change following interventions.

Methods: Isokinetic knee extensor strength was tested at 14 angular velocities in 17 adults with chronic post-stroke hemiparesis (>18 months), and 13 non-disabled controls. Identical tests were conducted on two occasions separated by two days. Test-retest reliability of maximal isokinetic torque was evaluated using intraclass correlation. Absolute reliability was assessed using standard error of measurement from which smallest real differences were derived.

Findings: Overall, intraclass correlation coefficients were excellent for both hemiparetic (0.891) and control (0.937) groups. Intraclass correlation coefficients for each criterion speed were also high for both groups (>0.86). Measurement error relative to the mean torque varied between 14.1% and 26.3% for hemiparetic subjects and 6.0-18.1% for controls. The smallest real difference relative to mean torque was 39.0-72.7% and 16.6-50.2% for hemiparetic and control subjects, respectively.

Interpretation: Isokinetic knee extension torque can be measured reliably in persons with chronic post-stroke hemiparesis and in non-disabled controls across a full functional range of concentric and eccentric speeds. Established measurement error and smallest real differences will aid interpretation of longitudinal observations of muscle performance in this clinical population.

Publication types

  • Controlled Clinical Trial
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adult
  • Aged
  • Female
  • Humans
  • Knee Joint / physiopathology*
  • Male
  • Middle Aged
  • Movement*
  • Muscle Contraction
  • Muscle, Skeletal / physiopathology*
  • Paresis / diagnosis*
  • Paresis / etiology
  • Paresis / physiopathology*
  • Physical Examination / methods
  • Range of Motion, Articular
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Stroke / complications
  • Stroke / diagnosis*
  • Stroke / physiopathology*
  • Task Performance and Analysis
  • Torque