Antagonistic pairs of muscles are muscle where one move the bone in one direction and the other moves it back the other way in transmission of nerve impulses to the muscles.
Demag, which manufactures and distributes telescopic and lattice boom cranes, is one of the leading mobile crane producers worldwide, with 2001 revenues of approximately $360 million.
Different types of cranes exist depending on the particular job that needs to be completed. One of the most commonly seen cranes seen in cities is a tower crane. Tower cranes were initially developed in Europe and are now popular all over the world. A tower crane is used in the construction of tall buildings. This type crane can reach up to 265 feet, out to 230 feet, and lift a total of approximately 20 tons. Tower cranes are fixed to the ground during the construction period.