Please excuse the time delay, which presumably results from the time Jos's voice takes to reach our computers recording the session.

The recording of my voice is immediate, and the combination sounds as though I interrupt Jos every time a question is asked!  The joys and challenges of technology.....

If you are unable to see the video below your systems administrator may have blocked access.  Ask them about how you can view the video, or watch from another location such as home.

The study referred to is:

Manual material handling advice and assistive devices for preventing and treating back pain in workers: a Cochrane Systematic Review.

Verbeek J, Martimo KP, Karppinen J, Kuijer PP, Takala EP, Viikari-Juntura E.

Occup Environ Med. 2011 Aug 17.