As an important consequence of our research, we question the relevance of the criteria of the WAD injury severity classification system. We showed that the musculoskeletal signs in WAD grade II are not characterized by muscle spasm, (i.e. increase of muscle activity), but rather by a decrease in muscle activation. Moreover, by also showing a strong association of this muscle activation pattern\ud
with fear of movement, we concluded that musculoskeletal signs in post traumatic neck pain do not reflect the severity of injury but rather the perception of symptoms, influenced by psychosocial factors from the fear avoidance model
