Intra-examiner reliability of lumbar spine and neuro-dynamic flexibility measurements in an older and overweight healthy asymptomatic population.

Abstract

Measurement of lumbar spine movement and neuro-dynamic flexibility is fundamental to clinical examination and forms part of most systems or protocols used to classify patients with low back pain. However, the increased age and body mass index reported in the chronic low back pain subgroup, may compromise the reliability of these measurements. Specifically, this relates to greater soft tissue excursion relative to the underlying bony landmarks used for these clinical tests. The objective of this research was to determine the intra-examiner reliability for six lumbar spine and two neuro-dynamic examination tests in older and overweight individuals selected to represent a similar age and body mass index of a chronic low back pain population. Nineteen volunteers (56.00 ± 7.62 years) performed sets of eight lumbar spine examination tests. Five repetitions of each set of tests were conducted with rest periods between sets. One examiner measured lumbar flexion, extension, right and left lateral flexion and rotation using a tape measure. A goniometer was used to measure Slump and Passive Straight Leg Raise (PSLR) test. Intra-class correlation coefficients (ICCintra) were calculated to evaluate the reliability of measurement for each test. The eight tests showed ICC ranges between `Large' and `Nearly Perfect' (0.68-0.99). Measurement of lateral flexion and rotation had the highest reliability and extension the lowest. This study was conducted on an asymptomatic older, overweight population and the ICC results support the suitability of these methods and tools for measurement in a clinical setting for this population demographic. Measurement reliability in the study population was comparable with previous research in populations of contrasting demographics. Accordingly, further investigation specifically in a chronic low back pain population is indicated as the paucity of previous literature for some of the movement tests disallowed comparisons, and the reliability reported in this study may not be directly transferable to a chronic low back pain population.