Preliminary comment on lumbar spondylosis - Specialist Medical ...

Certain limitations were acknowledged in using the normative database, but the
authors conducted a number of statistical exercises to correct for some of these,
...... eg at the theoretical extremes of the range, 150,000kg hrs would equal 1
kilogram lifted for a cumulated 150,000 hours or 150,000kg for 1 hour. [62] p.44.