Developing a Reliable Core Stability Assessment Battery for Patients With Nonspecific Low Back Pain

Study Design. Test-retest design. Objective. The objective was to examine the intrarater (test-retest) reliability of the core stability related tests and to develop a reliable core stability assessment battery. Summary of Background Data. Studies suggest that core stability exercises may improve function and decrease pain in patients with nonspecific low back pain (LBP). Reliable clinical tests are required to implement adequate rehabilitation and to evaluate results of these interventions. Methods. The study had a test-retest design. Thirty-three different tests that might relate to core stability were identified with their mostly used protocols. Five different components of core stability including endurance, flexibility, strength, functional performance, and motor control were assessed in 38 patients with nonspecific LBP. The same testing procedure was performed again after 48 to 72 hours. Intraclass correlation coefficients (ICCs), standard error of measurement, and minimal detectable change were calculated to assess the intrarater reliability. Results. The intrarater reliability of the tests ranged from little to very high (ICC = 0.08-0.98). Partial curl-up (ICC = 0.90), lateral bridge (ICC = 0.95-0.96), trunk flexor endurance (ICC = 0.97), sit and reach (ICC = 0.98), single-legged hop (ICC = 0.98-0.97), lateral step-down (ICC = 0.93-0.92), eyes open right and left leg unilateral stance (ICC = 0.97 and 0.91) tests had the highest intrarater reliability for each core stability component. Conclusion. The results indicated that the partial curl-up test (strength), side bridge and trunk flexor tests (endurance), sit- and reach test (flexibility), single-legged hop, and lateral step-down (functional), unilateral stance test with eyes open (motor control) had very high intrarater reliability. A core stability assessment battery involving these tests can be used in patients with nonspecific LBP to assess all components of core stability.