load testing of a cherry picker

Yes.

..."A load test is performed to verify that a specific crane or hoist will safely perform all of its functions while supporting a test load whose weight is at least equal to the equipment’s rated capacity. Because load tests confirm the ability of the crane and hoist to safely operate as intended, they must be completed whenever this overhead lifting equipment is newly installed, altered, repaired, or modified before being placed into service. Existing crane and hoist systems should likewise be load tested at a minimum of once every four years."...

"Because they are so critical to the safe operation of overhead cranes and hoists, there are several standards and specifications that detail load test requirements. These include:

• The Occupational Safety and Health Administration’s standard OSHA 1910.179(b)(3) and OSHA 1910.179(k)(2): Modified or rerated cranes shall be load tested. Test loads shall not be more than 125% of the rated load unless otherwise recommended by the manufacturer. The test reports shall be placed on file where readily available to appointed personnel.
• The American Society of Mechanical Engineers’ standards ASME B30.2: Overhead and Gantry Cranes, ASME B30.16: Overhead Underhung and Stationary Hoists, and ASME B30.17: Cranes and Monorails with Underhung Trolley or Bridge: New, reinstalled, altered, repaired and modified cranes and hoists should be load tested prior to initial use with a test load equal to 100% to 125% of rated load and to include all design functions (lift, lower, traverse length of bridge, traverse length of runway).
• The Crane Manufacturers Association of America standard CMAA Specification 78, section 4.7: Cites the load test requirements of OSHA 1910.179 and states a load test should be performed at a minimum of once every four years at 100% load with a pre-test and post-test inspection per periodic inspection guidelines, and there must be a written report of the load test and inspection results maintained on file for the life of the equipment."

http://www.overheadlifting.org/understand-the-basics-of-load-test-requirements/