Pivot joint in rotating an arm inward). When rotating the forearm, these movements are typically called pronation and supination. In the standard anatomical position, the forearms are supinated, which means that the palms are facing forward, and the thumbs are pointing away from the body. In contrast, a forearm in pronation would have the palm facing backward and the thumb would be closer to the body, pointing medially. Examples of a pivot joint include: In contrast, spherical joints (or ball and socket joints) such as the hip joint permit rotation and all other directional movement, while pivot joints only permit rotation. Pivot
Bacterial gliding Bacterial gliding Bacterial gliding is a process of motility whereby a bacterium can move under its own power. This process does not involve the use of flagella, pili, or fimbriae, all of which are more well-understood apparatuses used in bacterial motility. The mechanisms of gliding are only partially known. Generally, the process occurs whereby the bacterium moves along a surface in the general direction of its long axis. Gliding may occur via distinctly different mechanisms, depending on the type of bacterium. This type of movement has been observed in phylogenetically diverse bacteria such as cyanobacteria, myxobacteria, cytophaga, flavobacteria, and mycoplasmas,