[en] Background. Low back pain represents the leading cause of years lived with disability worldwide. Its prevalence is around 60 to 80%, and is higher in women and in people between 40 and 80 years. On the other hand, it has been documented that there is alteration of ventilatory mechanics in subjects with low back pain in comparison with healthy subjects, but the mechanisms that underlie this relationship or the characteristics that are altered are not known conclusively. Objective. The objective of this study is to determine if there are statistically significant differences in lung function and respiratory pattern between healthy subjects and subjects with chronic low back pain. Methods. Pilot study with cross-sectional study design of cases and controls, in which the recruitment of participants was carried out by diffusing the project in different ways. The main variables studied are the respiratory pattern, pulmonary function through forced spirometry and maximum voluntary ventilation are measured, as well as the motor control of the lumbo-pelvic region through the extensibility and the positional force of the hip flexor muscles. Outcomes. 11 subjects with chronic low back pain and 13 healthy controls were studied. The values of forced vital capacity (FVC) were significant (p=0.048), being lower in the group of cases. No significant differences were found between the groups in the respiratory pattern, nor in the parameters of maximum voluntary ventilation, despite the fact that in this the mean value observed is lower in the case group. Regarding the motor control, subjects with low back pain perform more compensations than healthy controls, both in the lower left (p = <0.01) and right (p=0.03). Regarding the interobserver reliability analysis, in the analysis of the respiratory pattern, weak reliability is obtained between the two experts and between the two novices, and a moderate reliability between the novel1 and expert1. A descriptive analysis was carried out using chi-square and T-student to analyze the difference between the groups.. Conclusions. There are statistically significant differences in certain parameters of lung function between healthy subjects and subjects with chronic low back pain, as well as in the positional strength of the lumbar stabilizing muscles.

[gl] Introdución. A dor lumbar representa a causa principal dos anos vividos con discapacidade a nivel mundial. A súa prevalencia situase entre o 60 e o 80%, e é maior en mulleres e en persoas entre 40 e 80 anos. Por outra parte, documentouse que existe alteración da mecánica ventilatoria en suxeitos con dor lumbar en comparación con suxeitos sans, pero os mecanismos que subxacen a dita relación ou as características que están alteradas non se coñecen de forma concluínte. Obxectivo. Determinar se existen diferenzas estadisticamente significativas na función pulmonar e no patrón respiratorio entre suxeitos sans e suxeitos con dor lumbar crónica. Material e método. Estudo piloto con deseño de estudo transversal de casos e controis, no que se realizou a contratación de participantes mediante a difusión do proxecto de diferentes xeitos. As principais variables estudadas son o patrón respiratorio, a función pulmonar a través dunha espirometría forzada e da máxima ventilación voluntaria, así como o control motor da rexión lumbo-pélvica a través da extensibilidade e da forza posicional da musculatura flexora da cadeira. Resultados. Estudáronse 11 individuos con dor lumbar crónica e 13 controis sans. Os valores da capacidade vital forzada (FVC) foron significativos (p = 0,048), sendo máis baixos no grupo de casos. Non se atoparon diferenzas significativas entre os grupos no patrón respiratorio, nin nos parámetros de ventilación voluntaria máxima, a pesar de que neste o valor medio observado é menor no grupo de casos. En canto ao control motor, os suxeitos con dor lumbar realizan máis compensacións que os controis sans, tanto no membro inferior esquerdo (p=<0,01) como no dereito (p=0,03). En canto á análise da fiabilidade interobservador, na análise do patrón respiratorio obtense unha feble fiabilidade entre os dous expertos e entre as dúas novelas, e unha fiabilidade moderada entre a novela1 e o experto1. Realizouse unha análise descritiva utilizando chi-cuadrado e T-student para analizar a diferenza entre os grupos. Conclusións. Existen diferenzas estadisticamente significativas en determinados parámetros da funcion pulmonar entre suxeitos sans e suxeitos con dor lumbar crónica, así como na forza posicional da musculatura estabilizadora lumbar.