The rotarod test consists of a continously rotating rod with barriers at both end, large enough for a mouse to fit between. This test measures how long a mouse can keep up with the constantly rotating rod, or the endurance of the mouse. Imagine a log roller from a children's playground, but the log is constantly rotating independant from the mouse. When the mouse falls off, the test is over.

The speed of the log can be constant or accelerated, and will measure balance, coordination, and motor skils in a mouse. I think this test is a good way to measure these qualities. Like the log roller from a child's playground, lots of motor control, balance, coordination, and endurance is required not to fall off. For example, the rotarod test can be used to measure how much a drug or neurodegenerative disease affects these qualities.

The rotarod test seems somewhat humane, since rodents should not be harmed in any way during the test, which will stop anyways when they cannot keep up. The only concern is to ensure the mice are not harmed when falling off the rotarod, but it seems rotarod kits ensure a safe falling distance for the mice.

https://qpsneuro.com/in-vivo-services/behavioral-tests/motor-ability-tests/rotarod-test/