After the Civil War , with the protection of the Thirteenth , Fourteenth , and Fifteenth Amendments to the Constitution and the Civil Rights Act of 1866 , African Americans enjoyed a period when they were allowed to vote , actively participate in the political process , acquire the land of former owners , seek their own employment , and use public ...
In the knee, for example, cracking or popping may occur if the patella (knee cap) is slightly out of alignment, and rubs on the adjacent tissues. Other causes of joint noise are the snapping of tendons or scar tissue over a prominence or something referred to as cavitation. Cavitation frequently occurs in synovial joints when a small vacuum forms in the synovial fluid and a rapid release produces a sharp popping or cracking sound.
Normal articular cartilage has no microvascular supply of its own and therefore is at risk in ischemic joints. In this tissue, the normal process of diffusion is supplemented by the convection induced by cyclic compression and release during joint usage. torn cartilage in the knee or a loose piece of bone or cartilage in the joint can do this. Once a joint is stuck in this way, it may need to be wiggled around to unlock it. This may also cause a pop. Finally, joints that are arthritic may crack and grind.