Allowing workers to do resistance training on the job is a recommended way for workplaces to help prevent and manage upper extremity musculoskeletal disorders (MSDs). That’s one of the key findings coming out of a recent systematic review conducted by an Institute for Work & Health (IWH) team.
The team emphasized that strong research evidence such as this is only part of evidence-based practice, which also incorporates the knowledge and experience of practitioners (e.g. occupational health and safety professionals) and end users (e.g. workers).
"We are not saying that workplaces should rush to implement resistance training," says Emma Irvin, head of IWH’s systematic review program and one of the lead investigators of this project. "However, we are suggesting that OHS practitioners consider it in their arsenal of prevention practices when it comes to upper extremity MSDs."
Resistance training refers to exercises that cause the muscles to contract against an external resistance (e.g. dumbbells, rubber exercise tubing, own body weight, etc.) with the expectation of increases in muscle strength, tone, mass and/or endurance.
"The studies on the effectiveness of resistance programs that we included in our review varied in the level of detail provided," says Irvin. "In those that supplied specifics, the resistance programs ranged from 20 minutes to one hour per week, spread across one or multiple days per week, with and without the involvement of a physiotherapist."
Stakeholders help craft practical messages
Done in partnership with stakeholders, including Ontario’s health and safety associations, this systematic review updates a 2008 review conducted by IWH that focused on the effectiveness of workplace intervention programs on preventing MSDs in the arm, shoulder and hand, in both office and non-office settings.
"Compared to the 2008 review, we found a higher proportion of high quality studies in the literature," says Irvin. "That higher proportion covered 29 different intervention categories, up from 19 in the last review, and allowed us to make practical recommendations on a number of them."
With respect to preventing and managing upper extremity MSDs, the 2014 review found:
- strong evidence of a positive effect for workplace-based resistance exercise training programs;
- moderate evidence of a positive effect for stretching exercise programs (including yoga), workstation forearm supports and vibration feedback on mouse use with computers;
- and moderate evidence of no effect for job stress management training, electromyographic (EMG) biofeedback (sensor pads that measure activity level in muscles), and workstation adjustments with minimal worker involvement.
"The finding about doing workstation adjustments alone not being effective is consistent across a number of our reviews," says Irvin. "In speaking with stakeholders, they concurred that workstation adjustments alone, without engaging the worker, cannot be expected to have a strong impact on upper extremity MSDs." The findings led the review team, in consultation with stakeholders, to craft a few practical messages for those involved in MSD prevention in workplaces (see sidebar).
How the systematic review was done
Systematic reviews set out to review and synthesize all that the research literature to date has to say on a given question. Designed to be replicable, they’re carried out according to clear and transparent methods, starting with a research question that states key parameters from the outset.
To conduct this systematic review, the team searched six databases and combed through almost 10,000 studies to filter the ones that met inclusion criteria for relevance and quality. It ended up synthesizing 61 studies, including the studies from the 2008 review, and weighing the quality of the relevant studies along 18 different domains. "One of the ‘good news’ messages coming out of this review is that well-designed studies are possible," says Irvin.
For more information about the findings of the systematic review, go to: www.iwh.on.ca/plenaries/2014-jun-03.