There are many things that can be done to eliminate and control the need to lift and carry things. Manual handling accounts for the majority of non-fatal injuries in construction, and construction workers have a high level of musculoskeletal disorders, in particular back problems. See:
[Estimated prevalence and rates of self-reported musculoskeletal disorders caused or made worse by current or most recent job, by occupation, for people working in the last 12 months, 2009/10 ](http://www.hse.gov.uk/statistics/lfs/msdocc2.xls).
This leads to many working days lost due to ill health and injury and is also reason why many people have to stop working in construction.
Use a hierarchy of controls to look at manual handling tasks and only resort to handling and lifting where there are no other options.
[Manual handling and musculoskeletal disorders (MSD)](http://www.hse.gov.uk/construction/healthtopics/msd.htm)