How to differentiate between a bony or muscular disorder in neck pain?
Comparison of active and passive range of motion is useful for differentiating articular from soft-tissue disorders. Passive neck range of motion is best performed by supporting (cradling) the head while the patient is supine. Full range of the cervical spine may then be tested: flexion, extension, rotation, and lateral bending. During rotation and lateral bending, ipsilateral discomfort elicited in the direction of movement is suggestive of bony pain. Pain and/or tightness produced on the contralateral side usually implicate a muscular disorder. Finally, palpable tenderness of the spinous processes may indicate bony pathology, whereas local tenderness of paraspinous muscles usually indicates myofascial pain. Passive range of motion (and provocative tests) should not be performed if instability or fracture of the cervical spine is suspected.