I have noted that sometimes in the slump knee bend test (see figure), that cervical flexion and extension will alter evoked lateral thigh symptoms, the kind that may get labeled as ITB band syndrome.
It is quite interesting when the ITB symptoms and even tightness, evaporate before your eyes and in your hands. It does suggest that in some cases there is a neurogenic component to ITB syndrome, maybe in the fascia but more likely spinal or even thoracic. From the clinical angle, the test is certainly worth performing.
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Fig 11.3A From Butler DS 2000 The Sensitive Nervous System, Noigroup, Adelaide