[Subgroup-specific therapy of low back pain: description and validity of two classification systems]

In spite of profound advances in the diagnosis and therapy, low back pain (LBP) remains one of the main challenges for health systems in western industrialized countries. Clinical trials and meta-analyses typically show heterogeneous evidence and small effect sizes. One explanation for this phenomenon is the heterogeneous nature of the population of patients with LBP, not adequately considered in clinical practice and research. Recent studies and one meta-analysis show that therapy which is specifically directed at well defined subgroups leads to improved effectiveness of interventions, especially for non-surgical interventions such as manual therapy or physiotherapy.

This article aims to describe the process of classification and to critically evaluate the underlying evidence.

Two validated and commonly used classification systems were selected and their reliability and validity were critically appraised.

The treatment-based classification system was primarily developed and validated for patients with acute LBP. Based on prognostic factors and clinical prediction rules, patients are classified into one of four treatment based categories: traction, manipulation, specific exercises and stabilization. The movement and motor control impairment classification system is based on movement-related, cognitive and psychosocial factors and was developed for patients with chronic LBP. Maladaptive movement and motor control impairments are considered as underlying mechanisms. Three broad subgroups are proposed: firstly, a group with specific pathologies, such as spinal stenosis or disc prolapse with radiculopathy, secondly a group with dominant psychosocial factors and thirdly a group with maladaptive motor control patterns that drive the disorder with either movement impairments or motor control impairments.

The reliability of the described classification systems is moderate to good, aspects of validity have been shown. Their implementation in clinical practice seems recommendable.