Fifty pounds is a considerable amount of force. If this requirement came from a job analysis, great. If it came from the DOT be careful that it is the true amount of initial force and not just a reflection of the limitations of the DOT system.

True, sleds/carpets/floors will differ but our Isernhaben sled requires 175# load on level carpet to require 50# force...hope this helps
Betty

It depends on the sled you are using and the flooring the sled is being pushed on; rather its carpeting, tile, or floor. You will need to use a guage to measure the force. I have been told that when in a pinch you can also use a dynamometer to measure the force. Hope this is helpful.