Human arm as a class 3 lever. ... Notice how the draw hook is a broad, curved shape–functioning as a spring. The lever pulls it taught and that tension holds the latch.

Rats were first trained to obtain a water reward by depressing a spring-loaded lever to proportionally move a robot arm to a water dropper (Fig. 1.). On release, water was transferred to the mouth ...

This week during surgery in suburban St. Louis, a 7-inch turn signal lever from that T-Bird was removed from his left arm. Dr. Timothy Lang removed the lever Wednesday during a 45-minute operation.