Manual Handling Injury Prevention signposts to research — Kimberley Schofield
What constitutes effective manual handling training? A systematic review
A literature review paper of 53 research papers into the effectiveness of manual handling training.
from the abstract's conclusion - "The evidence collected indicates that manual handling training is largely ineffective in reducing back pain and back injury. High priority should be given to developing and evaluating multidimensional interventions, incorporating exercise training to promote strength and flexibility, which are tailored to the industrial sector."
However the paper does comment that a large proportion of the 53 research papers that were reviewed low of low quality, so got to take it with some salt.
My thoughts are to first focus on where you can physically change how manual handling must be done, e.g. redesign of workspaces, provision of suitable tools, and/or reassessment of standard methods for tasks (breaking down more strenuous tasks into smaller sub-tasks). Although on that last one you've got to be careful - I don't know how true the anecdote is but one story of introducing 25kg bags for concrete drymix bags (compared to 40kg) actually had a negative effect as now it was possible to easily move 50kg at a time rather than the previous 40kg.
The focus on fitness for work by, as the paper indicates, providing strength and flexibility training might give more (long term) bang for the buck than training of "good lifting techniques" (but as expected of an academic paper this questions needs further research...). I wonder what staff reaction would be if workers where heavy manual handling was required were provided a gym on site (or gym membership) and "X hours of strength and flexibility training per week" was part of their job description - i.e. free gym membership and get paid to work out to build/maintain the fitness for work required for the jobs they are required to complete.