Convergent validity of the position-reposition and thoracolumbar dissociation tests in patients with recurrent low back pain in remission.

BACKGROUND

Lumbopelvic sensorimotor control (SMC) impairments during remission from low back pain (LBP) may contribute to its recurrence. Clinical assessment of lumbopelvic SMC can support management of recurrent LBP. Such assessments should demonstrate sufficient convergent validity, as outcomes inform clinical decision-making for SMC-therapy implementation.

OBJECTIVE

To evaluate the convergent validity of two SMC tests (position-reposition test and thoracolumbar dissociation test) in individuals with recurrent LBP in remission according to COSMIN guidelines.

METHODS

Fifty-three participants with recurrent LBP in remission (19 female) performed the position-reposition and thoracolumbar dissociation tests. A blinded examiner scored both tests, while objective measures were collected using spinal inclinometers and surface electromyography of trunk muscles. COSMIN-based hypotheses were used to evaluate convergent validity. Relationships between clinical scores and objective measures were examined with Spearman's rho.

RESULTS

The position-reposition test showed sufficient convergent validity for all criteria and the total score. For the thoracolumbar dissociation test, L5 range of motion (ROM), T5/L5-ratio, L5 movement smoothness, and their combined z-score demonstrated sufficient convergent validity. In contrast, muscle activation and L1/L5-ratio showed insufficient convergent validity. Including muscle activation in the combined z-score of ROM and smoothness did not improve the convergent validity.

CONCLUSION

The position-reposition test can be clinically evaluated with sufficient convergent validity. The clinical assessment of thoracolumbar dissociation should prioritize pelvic and thoracic ROM and the smoothness of pelvic movement, while muscle activation should be interpreted with caution. Both tests can be used in clinical practice and may help guide clinical decision-making in managing recurrent LBP.