(1) No objective clinical findings are present. Subjective complaints may be present or absent.

(2) Mild or moderate dorsal impairment, with objective clinical findings of such impairment, without significant objective neurological findings, with or without X-ray changes of narrowed intervertebral disc spaces and/or osteoarthritic lipping of intervertebral margins. Includes the presence or absence of reflex and/or sensory losses.

This and the subsequent category include the presence or absence of pain, locally or radiating from the dorsal area.

(3) Marked dorsal impairment, with marked objective clinical findings, with marked X-ray findings of narrowed intervertebral disc spaces and/or osteoarthritic lipping of vertebral margins, with significant objective neurological deficits, complaints and/or findings, deriving from dorsal impairment.