Prognostic values of physical examination findings in patients with chronic low back pain treated conservatively: A systematic literature review

Abstract

Background: Most patients undergo physical examination. However, low back pain can only rarely be clearly diagnosed as having an irrefutable pathoanatomic cause on the basis of the classical battery of noninvasive physical examination procedures. However, physical examination findings are also used to predict the prognosis of treatment of chronic low back pain. A systematic review of the clinical literature is needed for an understanding of findings in this area. Objectives: To establish whether various physical examination procedures can be used to predict treatment outcome in the conservative (noninvasive) treatment of chronic low back pain. Data Sources: From 910 titles published between 1986 and 1998, 10 original research reports were selected. These were obtained by means of a computerized MEDLINE search through use of various combinations of the key words low back pain, treatment, physical findings, predictors, prognosis, prognostic factors, prognostic indicators, and predictors and outcome(s); manual search strategies were also used. Data Synthesis: Articles that fitted the objectives of this review were retained and systematically reviewed for the prognostic value of the relevant tests/observations. In addition, results were studied in relation to type of outcome variable and type of treatment. Results: The most commonly investigated tests were lumbar range-of-motion tests, which were found to have a clear-cut significant predictive value in 3 of 9 studies. Further analyses in relation to definition of outcome (back-to-work or reduction of symptoms) were not possible because study results were usually not clearly reported for each definition and because therapies were multimodal rather than distinctly well defined. Conclusions: This area has not been fully investigated. Therefore, there is no satisfactory answer to the question of whether some physical examination tests have a prognostic value in the conservative treatment of chronic low back pain. (J Manipulative Physiol Ther 2001;24:292-5)

Introduction

Low back pain (LBP)—in particular, chronic LBP—remains a clinical enigma. Today it is generally accepted that adherence to the traditional pathoanatomic model has failed to contain this problem despite the considerable resources that have been provided in the form of treatment, ergonomic support, and easily available sickness leave. Presently, much emphasis is being placed on an alternative model, the biopsychosocial concept, the essence of which has been clearly stated by Waddell et al¹: “Whatever treatment we use must be directed to the patient rather than to the spine or to pain alone.” One consequence of this paradigm shift is that clinicians now emphasize nonspinal factors, such as psychologic traits and social circumstances, rather than clinical findings in relation to diagnosis, therapeutic decisions, and the prediction of treatment outcome in chronic LBP of nonspecific type. As a practical consequence of this development, the traditional physical examination could lose much of its importance.

However, before one dismisses such a well-entrenched clinical procedure, it is necessary to study its advantages and limitations. For example, although it is rare that a classical, specific, substantive, pathoanatomic diagnosis can be reached with the help of a traditional physical examination in chronic LBP,² such examinations will probably continue to play a role in clinical practice, both in the making of individual diagnoses (at least diagnoses by exclusion) and in the making of prognoses as to treatment outcome. For example, clinicians might consider a patient with chronic LBP to have a better prognosis if the only positive finding is a well-defined, painful response to certain lumbar movements in comparison with what is seen in a patient with several other positive tests but normal ranges of motion. Furthermore, a patient with a positive straight-leg-raise test at 60° would probably be considered to have a better prognosis than one with reduced reflexes and definite signs of nerve root involvement.

We performed a systematic literature review to gain insight into the extent to which the prognostic value of physical examination findings has been covered in the scientific literature in relation to clinical outcomes of the noninvasive treatment of chronic LBP.