A mild knee crunch, unaccompanied by pain or limited mobility, is not dangerous in the early stages. The crunching may be caused by a disruption of the joint's nutritional supply, calcification of muscle fibers and ligaments, or muscle spasms. However, over time, these same causes can lead to the development of osteoarthritis, so delaying treatment for too long is also not recommended.
A knee crunching sound, similar to a creaking sound, or accompanied by pain or limited mobility, may indicate degeneration of the meniscus, articular surfaces, or the appearance of bone spurs. This crunching should be treated immediately, as each new movement can lead to injury to the affected joint.