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E. Adelt1, T. Schöttker-Königer1, K. Lüdtke2,3, A. Schäfer1
1University of Applied Sciences and Arts Hildesheim, Faculty of Social Work and Health, Hildesheim, Germany, 2University of Luebeck, Institute of Health Sciences, Department of Physiotherapy, Pain and Exercise Research (P.E.R.L.), Luebeck, Germany, 3The Jerzy Kukuczka Academy of Physical Education, Institute of Physiotherapy and Health Sciences, Laboratory of Pain Research, Katowice, Poland
Background: Impaired lumbar movement control (LMC) is one possible factor for the development and maintenance of non-specific low back pain (NSLBP). The use of multiple tests to evaluate LMC is recommended to guide targeted treatment. Until now, psychometric properties have only been investigated for single LMC tests.
Purpose: The aim of this study was to develop a battery of LMC tests and to investigate its dimensionality and psychometric properties.
Methods: A systematic literature review was conducted to identify LMC tests. LMC tests with at least good reliability (κ≥0,61) were included. The dimensionality of the battery of LMC tests was examined. Based on item response theory (IRT), psychometric properties such as difficulty, discrimination and information of single items and the entire battery of LMC tests, were determined. The relationship between LMC ability and number of negative test results was investigated.
Results: In total, 277 participants with NSLBP were recruited and tested by 21 physiotherapists in 19 outpatient physiotherapy clinics and rehabilitation centers in Germany and Austria. 15 tests for LMC were included.
The battery of 15 LMC tests showed a direction-specific structure: extension, flexion and rotation/lateral flexion, for which unidimensionality and local independence were confirmed (eigenvalue >1; factor loading >0,4, Yen´s Q3 <0.2). 4 items for flexion control, 4 items for extension control and 5 items for rotation/lateral flexion control were extracted. Flexion control tests were the easiest to perform (item difficulty: -1,98 to -1,31) whereas rotation/lateral flexion tests were the most difficult (-1,3 to -0,08). Participants with NSLBP showed normal performance in 3.6 (out of 4) tests for flexion control, 2.4 tests (out of 4) for extension control and 3 (out of 5) for rotation/lateral flexion control. More than 80% of all participants with NSLBP showed at least one impaired direction of LMC, whereby in more than 20%, one direction was more than 1 SD worse than the average performance.
The battery of 15 LMC tests showed a direction-specific structure: extension, flexion and rotation/lateral flexion, for which unidimensionality and local independence were confirmed (eigenvalue >1; factor loading >0,4, Yen´s Q3 <0.2). 4 items for flexion control, 4 items for extension control and 5 items for rotation/lateral flexion control were extracted. Flexion control tests were the easiest to perform (item difficulty: -1,98 to -1,31) whereas rotation/lateral flexion tests were the most difficult (-1,3 to -0,08). Participants with NSLBP showed normal performance in 3.6 (out of 4) tests for flexion control, 2.4 tests (out of 4) for extension control and 3 (out of 5) for rotation/lateral flexion control. More than 80% of all participants with NSLBP showed at least one impaired direction of LMC, whereby in more than 20%, one direction was more than 1 SD worse than the average performance.
Conclusion(s): In conclusion, each direction of LMC tests should be examined separately. The battery of LMC tests is most suitable to examine individuals with moderate to poor LMC. The order of testing can be individualized according to test difficulty, so that the number of required tests to diagnose an impaired LMC can be reduced. As the battery of LMC tests investigated in this study is relatively easy, more difficult items should be developped to enable more challeging testing.
Implications: In clinical practice, each direction of LMC tests should be examined separately to develop targeted treatment strategies. Tests can be ordered according to test difficulty, so that only three tests are initially required to screen for impaired LMC. Therefore the battery of tests is less time-consuming and gives more information for clinical management than previous tests for LMC.
Funding, acknowledgements: This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
Keywords: Lumbar movement control, non-specific low back pain, item response theory
Topic: Musculoskeletal: spine
Did this work require ethics approval? Yes
Institution: University of Applied Sciences and Arts Hildesheim, Germany
Committee: Ethics Committee University of Applied Sciences and Arts Hildesheim, Germany
Ethics number: 43511
All authors, affiliations and abstracts have been published as submitted.
