Anatomía funcional del tronco. Valoración dinámica mediante técnicas no invasivas de la región lumbo-pélvica en personas sanas y pacientes con historia de dolor lumbar.

Abstract

INTRODUCTION: Dynamic tests have been used to distinguish low back pain patients from pain-free subjects. However, we couldnt find studies which compared lumbopelvic motion and erector spinae activity patterns registered in a non-invasive way between different groups of patients with low back pain and specific alterations of the lumbo-pelvic anatomy. MATERIALS AND METHODS: 50 pain-free and 50 low back pain patients, with specific groups of discal herniation, spondylolisthesis, bilateral sacroiliitis and ankylosing spondylitis, were studied. Using non-invasive techniques the patterns of lumbo-pelvic motion and electromyographic activity of the erector spinae were analyzed during standardized trunk flexion-extension cycles. All data were synchronized. Variables: average myoelectrical activity and degrees of lumbo-pelvic flexion at each stage of movement; maximum ranges of trunk, hip and spine flexion; time during which the subjects kept lumbar and hip flexion over 90% of their maximum; duration, start and end of erector spinae relaxation; relaxation indexes of myoelectrical activity at flexion, extension and flexion-extension. Normal distribution and reliability of the variables were confirmed (Kolmogorov- Smirnov test, Intra-class Correlation Coefficient, Standard Error of Measurement). Statistically significant differences were shown by the Student t-test for independent measurements and one-factor ANOVA, with Bonferroni test for post-hoc testing. RESULTS: Most patients showed the flexion-relaxation phenomenon of the erector spinae. Hip motion pattern showed no differences between any of the groups, whereas all patients maximum ranges of lumbar flexion and times of lumbar flexion over 90% of its maximum in all the patients were lower than controls. Unspecific low back pain patients showed alterations of lumbar motion and erector spinae activation patterns, whereas spondylolisthesis group showed only alterations of lumbar motion pattern and discal herniation and ankylosing spondylitis groups showed only alterations of erector spinae activation. DISCUSSION: Our results show protective movement strategies during trunk flexionextension, specific of each lumbar anatomy alteration. Such strategies could be explained according to the anatomy and neurophysiology of the lumbo-pelvic region, by means of spinal or supraspinal reflexes. Our method not only brings forward unpublished data but also could have clinical applications: diagnose of low back pain causes, evaluation of treatment techniques, patients follow-up of simulators detection.