Age-related test-retest reliability of isometric trunk torque measurements in patiens with chronic low back pain

J Rehabil Med. 2016 Nov 11;48(10):893-902. doi: 10.2340/16501977-2164.


Objective: To investigate the short- and long-term reliability of isometric trunk strength measurements in patients with chronic low back pain in different age groups.

Design: Test-retest reliability study.

Patients: A total of 210 patients (age groups 18-39, 40-59 and 60-90 years).

Methods: Patients performed testing at baseline, 1-2 days (day 2) and 6 weeks.

Results: Only the oldest age group showed similar extension strength on all three test days All age groups showed significant changes in rotation and flexion scores from baseline to 6 weeks. Younger age groups (18-39 and 40-59 years) showed significant increases in extension, flexion, and rotation strength at both short-term (baseline to day 2) and long-term (baseline to 6 weeks) retests, but not from day 2 to 6 weeks. In patients over 60 years of age the smallest real differences normalized to baseline (%) were smaller from day 2 to 6 weeks than from baseline to 6 weeks. Long-term intraclass correlation coefficients were lowest between baseline and 6 weeks. No relevant impacts of feelings, motivation, or pain on reliability were detected.

Conclusion: Reliability of isometric trunk strength measurements in patients with chronic low back pain is similar in older and younger patients. Short-term test repetition a few days after baseline is recommended, if clinically feasible, and especially in research evaluating the effects of exercise on strength.

Publication types

  • Evaluation Study

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Aging / physiology*
  • Exercise / physiology
  • Female
  • Humans
  • Isometric Contraction / physiology*
  • Low Back Pain / physiopathology*
  • Male
  • Middle Aged
  • Muscle Strength
  • Muscle, Skeletal / physiopathology
  • Range of Motion, Articular
  • Reproducibility of Results
  • Torque*
  • Torso / physiopathology*
  • Young Adult