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.
1) Pain-free Popping: Popping noises in the knee often occur without any pain, in which case they are nothing to worry about. 2) Painful Popping Noise at time of Injury: Sometimes when the knee is injured e.g. twisting awkwardly, there is a sudden, loud pop at the same time indicating damage to part of the knee. 3) Recurrent Painful Popping Noises not Caused by an Injury: Knee pain and popping can come on gradually with no obvious cause.