Inter-rater reliability of three standardized functional tests in patients with low back pain

Johan Tidstrand,Eva Horneij

doi:10.1186/1471-2474-10-58

Abstract

BackgroundOf all patients with low back pain, 85% are diagnosed as "non-specific lumbar pain". Lumbar instability has been described as one specific diagnosis which several authors have described as delayed muscular responses, impaired postural control as well as impaired muscular coordination among these patients. This has mostly been measured and evaluated in a laboratory setting. There are few standardized and evaluated functional tests, examining functional muscular coordination which are also applicable in the non-laboratory setting. In ordinary clinical work, tests of functional muscular coordination should be easy to apply. The aim of this present study was to therefore standardize and examine the inter-rater reliability of three functional tests of muscular functional coordination of the lumbar spine in patients with low back pain.MethodsNineteen consecutive individuals, ten men and nine women were included. (Mean age 42 years, SD ± 12 yrs). Two independent examiners assessed three tests: "single limb stance", "sitting on a Bobath ball with one leg lifted" and "unilateral pelvic lift" on the same occasion. The standardization procedure took altered positions of the spine or pelvis and compensatory movements of the free extremities into account. The inter-rater reliability was analyzed by Cohen's kappa coefficient (κ) and by percentage agreement.ResultsThe inter-rater reliability for the right and the left leg respectively was: for the single limb stance very good (κ: 0.88–1.0), for sitting on a Bobath ball good (κ: 0.79) and very good (κ: 0.88) and for the unilateral pelvic lift: good (κ: 0.61) and moderate (κ: 0.47).ConclusionThe present study showed good to very good inter-rater reliability for two standardized tests, that is, the single-limb stance and sitting on a Bobath-ball with one leg lifted. Inter-rater reliability for the unilateral pelvic lift test was moderate to good. Validation of the tests in their ability to evaluate lumbar stability is required.

Highlights

Of all patients with low back pain, 85% are diagnosed as "non-specific lumbar pain"
Subjects Patients consulting a physiotherapist due to low back pain with or without referred pain in the lower limb, or for arm and/or shoulder pain were recruited from a private physiotherapy clinic in the south of Sweden
Visual analogue scale (VAS) > 70 mm, previous known trauma or operation of the lower extremity which could jeopardise the performance of the tests, and known neurological or rheumatological disease

Summary

Introduction

Lumbar instability has been described as one specific diagnosis which several authors have described as delayed muscular responses, impaired postural control as well as impaired muscular coordination among these patients. This has mostly been measured and evaluated in a laboratory setting. 15% of patients with low back pain (LBP) are given a specific pathological diagnosis, the remaining 85% are diagnosed as "non-specific lumbar pain" [1] For this latter group, treatment as well as the evaluation of treatment are considered difficult. Each individuals capacity for keeping the spine in the neutral position was defined as "functional muscular coordination"

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