Knee pain and popping is a common problem and can be caused by a number of factors. Another term commonly used for popping in the knee is Crepitus, which essentially means a noisy joint, whether it be popping, clicking, cracking or snapping.
The final type of erosion is attrition. Attrition is a way of eroding the riverâs load, not the bed and banks. Attrition is where pieces of rock in the riverâs load knock together, breaking chunks of rock off of one another and gradually rounding and shrinking the load.
A rotating drum causes friction and attrition between steel rods and ore particles. The wearing away of granule surface material by attrition is the opposite of layering. Attrition is when particles wear away from a solid surface because particles of a hard material touch it. Collins English Dictionary.