I googled osha weight lifting requirements:
Issue: When applying for a position with a local ambulance service, potential employees are required to perform certain physical tests, the last of which is carrying a 160-pound weight up and down five flights of stairs three times.
Question: Is there a policy or guide which states the maximum weight a person may lift?
Reply: OSHA does not have a standard which sets limits on how much a person may lift or carry. However, a sister agency, the National Institute for Occupational Safety and Health (NIOSH), has developed a mathematical model which helps predict the risk of injury based on the weight being lifted and accounts for many confounding factors. The model is based on previous medical research into the compressive forces needed to cause damage to bones and ligaments of the back.
NIOSH has shown through research that a lifting index greater than 3.0 can clearly be linked to an increased risk of back and other injuries. Based on the conditions you described, and assuming ideal conditions for grip, twisting and the other factors in the equation, the NIOSH Lifting Equation gives a lifting index of 3.1. This would classify the lift as a highly-stressful lift and would indicate that nearly all workers would be at an increased risk of injury when carrying 160 pounds. The Applications Manual for the Revised NIOSH Lifting Equation can be found on the NIOSH website listed below. It should be noted however, that the NIOSH criteria are not mandatory.
While OSHA does not have a standard written specifically for the problem you raised, employee exposure to hazards related to heavy lifting and back injuries can be addressed under Section 5(a)(1) of the OSH Act, commonly referred to as the General Duty Clause. The General Duty cause states that:
Each employer -- shall furnish to each of his employees employment and a place of employment which are free from recognized hazards that are causing or are likely to cause death or serious physical harm to his employees;
In practical terms, the General Duty Clause says that if an employer knowingly exposes their employees to a recognized hazardous condition, then that employer may be in violation of the OSH Act.
If you would like more information on lifting hazards both OSHA and NIOSH have information on their respective web sites which can be found at:
OSHA:
www.osha.gov/SLTC/ergonomics/index.html
NIOSH:
www.cdc.gov/niosh/topics/ergonomics/default.html#lift
summary: the 160# emt lifting standard poses a real danger to your back... stay safe.