The complex spine: the multidimensional system of causal pathways for low-back disorders.

OBJECTIVE: The aim of this study was to examine the logic behind the knowledge of low-back problem causal pathways.
BACKGROUND: Low-back pain and low-back disorders (LBDs) continue to represent the major musculoskeletal risk problem in the workplace,with the prevalence and costs of such disorders increasing over time. In recent years, there has been much criticism of the ability of ergonomics methods to control the risk of LBDs.
METHOD: Logical assessment of the systems logic associated with our understanding and prevention of LBDs.
RESULTS: Current spine loading as well as spine tolerance research efforts are bringing the field to the point where there is a better systems understanding of the inextricable link between the musculoskeletal system and the cognitive system. Loading is influenced by both the physical environment factors as well as mental demands, whereas tolerances are defined by both physical tissue tolerance and biochemically based tissue sensitivities to pain. However, the logic used in many low-back risk assessment tools may be overly simplistic, given what is understood about causal pathways. Current tools typically assess only load or position in a very cursory manner.
CONCLUSION: Efforts must work toward satisfying both the physical environment and the cognitive environment for the worker if one is to reliably lower the risk of low-back problems. APPLICATION: This systems representation of LBD development may serve as a guide to identify gaps in our understanding of LBDs.