Open Access Open Badges Research article

Effectiveness of physical training for self-employed persons with musculoskeletal disorders: a randomized controlled trial

Judith Heinrich12, Johannes R Anema34, Ernest MM de Vroome1 and Birgitte M Blatter12*

Author Affiliations

1 TNO Quality of Life, Polarisavenue 151, PO Box 2130 AS Hoofddorp, The Netherlands

2 Body@Work, Research Center Physical Activity, Work and Health TNO Vumc, Amsterdam, The Netherlands

3 Department of Social Medicine, Institute for Research in Extramural Medicine, VU University Medical Center, Van der Boechorststraat 7, 1081 BT Amsterdam, The Netherlands

4 Research Center for Insurance Medicine AMC-UWV-VUmc, Amsterdam, the Netherlands

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BMC Public Health 2009, 9:200  doi:10.1186/1471-2458-9-200

Published: 23 June 2009



Despite the fact that the population of self-employed persons is still growing and at risk for long term disability due to a number of risk factors, there is still a lack of information on the effectiveness of interventions for this specific group.


To determine the effectiveness of physical training without a cognitive behavioral component and workplace specific exercises (PT) and physical training with a cognitive behavioral component and workplace specific exercises (PTCBWE), we conducted a pragmatic Randomized Controlled Trial, stratified into two groups. Self-employed persons with a new work disability claim because of musculoskeletal disorders were randomized to PT (n = 53) or PTCBWE (n = 76), or to a corresponding usual care group (n = 50 and n = 75 respectively). Both types of training consisted of cardiovascular training, strengthening, relaxation and posture exercises and took place two or three times a week, for 1–1.5 hours, during three months, also if someone had already returned to work full-time. The primary outcome measure was claim duration (in days) during 12 months follow-up. Pain severity and functional status were secondary outcome measures. All data were assessed at baseline and at 6 and 12 months follow-up. The data with regard to claim duration were analyzed by survival analysis and Cox regression analysis. Secondary outcome measures were analyzed by means of linear regression analysis.


After 12 months of follow-up there was no difference in claim duration between PT and usual care (Hazard Ratio 0.7; 95%CI, 0.4–1.1; p = 0.12) or PTCBWE and usual care (Hazard Ratio 0.9; 95%CI, 0.6–1.4; p = 0.72). Both types of physical training and usual care improved in pain and functional status over time, but there was only a statistically significant difference in favor of PT on pain improvement at 6 months.


In this study, physical training with and without a cognitive behavioral component and workplace specific exercises for self-employed persons with musculoskeletal disorders was not shown to be effective on claim duration, pain severity and functional status at 12 months follow-up.

Trial registration

Current Controlled Trials ISRCTN67766245.