Functional Tests Predicting Return to Work of Workers with Non-Specific Low Back Pain: Are There Any Validated and Usable Functional Tests for Occupational Health Services in Everyday Practice? A Systematic Review.

The literature predominantly advocates subjective perception of disability and pain as an outcome measure for the functional evaluation of patients with low back pain (LBP). Physical outcome measurements are almost completely ignored. In this systematic review, we focused on physical functional measurements that can contribute to the prediction of patients' return to work (RTW) readiness after sick leave or rehabilitation. Searches were conducted in July 2022 without any time limit in the Cochrane Library, PEDro, PubMed and Scopus databases for functional and clinical tests reliable and applicable in clinical practice without demanding equipment. Two independent researchers extracted the data from the included articles in a standardised data collection form, and a third researcher validated the data extraction. No date restriction was applied. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines in conducting the review. We found seven original articles, including six with an impact on predicting RTW. We found four fair and three poor original studies fulfilling our criteria. We found the Back Performance Scale (BPS) and back endurance test to be the most promising tests for occupational health service and the clinical practitioner. Radiation of back pain, with or without neurological deficiencies, had some predictive value in terms of RTW, too. The working conditions vary a lot, which causes inconsistency in the studies and in their interpretation. Functional tests could complete the widely used working ability evaluations methods such as the Work Ability Index (WAI) and are worth considering for future research. Overall, more research is needed in this field. The question of when LBP patients can resume everyday activities and work is not possible to determine with functional tests alone. Psychosocial aspects and work demands must be considered. PROSPERO: CRD42022353955. The study was funded by the University of Helsinki.