Many people are frightened by the noises their knees, shoulders or spine make, but the good news is that these noises are perfectly normal. In fact 99% of all knees make noises to a lesser or greater extent according to McCoy’s study (1987).
The causes of these noises are not always clear or easy to tell, but could be structures in the joints or soft tissues rubbing and sliding against each other. The main thing is that there is a very poor association with noises and pathology in different areas of our body.
And noises without any other symptoms are perfectly normal and we have no evidence that predicts future problems or pathology. Just as you don’t panic when your stomach gurgles, you shouldn’t panic when a joint pops or crackles.
The crunching of the knees, for example, can induce negative beliefs, generate worry, and eventually fear and avoidance behaviors. Some health professionals often do not give it the necessary importance, failing to assess and manage wrong and negative beliefs. Given the high prevalence of symptoms described, such as noise, it is important to explain and reassure the patient that the noise is completely normal if there are no associated symptoms.
On the other hand, no research to date has proven that crepitus is associated with any active pathology, and its significance for patients is still under investigation – 99% of the individuals studied had crepitus but no pain – the extra-articular mechanism is usually explained by the friction of structures such as tendon and bone – the intra-articular is explained by the formation of vacuum generated by the movement of the bones, which collapses into gas, small amounts of synovial fluid, characterized by the crunching sound heard. The classic “click” of joint adjustments, popularly related to a bone that was out of place, is just liquid that transforms into gas. Interesting, isn’t it?
Regular finger crunching over the years also did not prove that patients developed osteoarthritis. During vibratory arthrography tests we perceive a decrease in motion-related noises in knees with osteoarthritis and in the advanced stage of patellofemoral alteration, probably associated with hypomobility and less lubrication – the “Elans”, a type of African antelope, uses crunching as a way to show superiority – perhaps we should stop thinking of crepitus as associated with degeneration or pathology, but as a sign that we have mobile and well-lubricated joints.