Reliability and validity of a new objective tool for low back pain functional assessment
Daniel Sánchez-Zuriaga1, Juan López-Pascual, David Garrido-Jaén
1Department of Anatomy and Human Embryology, Faculty of Medicine, Universitat de València, Av. Blasco Ibáñez 15, València, Spain. Daniel.Sanchez@uv.es
Study Design:
Classification and functional assessment model for nonspecific low back pain (LBP) patients and controls on the basis of kinematic analysis parameters.
Objective:
Develop a logistic regression model using kinematic analysis variables to (1) discriminate between LBP patients and controls and (2) obtain objective parameters for LBP functional assessment.
Summary Of Background Data:
Functional assessment of spinal disorders has been carried out traditionally by means of subjective scales. Objective functional techniques have been developed, which usually involve the application of external loads or the analysis of highly standardized trunk flexion-extension maneuvers. Few studies have used everyday activities such as sit-to-stand or lifting an object from the ground. They have shown that the motion patterns of LBP patients differ from those of healthy subjects. Nevertheless, very few studies have tried to correlate objective findings to the results of subjective scales, and no previous study has developed a LBP classification and functional assessment model on the basis of kinematic analysis of everyday activities.
Methods:
Sixteen controls and 39 LBP patients performed a sit-to-stand task, and lifted three different weights from a standing position. The vertical forces exerted and the relative positions of the lower limb and the cervical, thoracic, lumbar, and sacroiliac regions were recorded. Reliability was determined from repetitions of the tests performed by the control group. Binary logistic regression analyses were computed. The results of the selected regression equation were correlated to the Oswestry Disability Index scale results, to check the validity of the procedure for the measurement of functional disability.
Results:
Reliability of the parameters was good. The selected regression model used two variables, and correctly classified 97.3% of the patients. High correlations were found between the results of this regression equation and the Oswestry Disability Index scale.
Conclusion:
It is possible to distinguish LBP patients from healthy subjects by means of the biomechanical analysis of everyday tasks. This kind of analysis can produce objective and reliable indexes about the patients' degree of functional impairment.
