Which is not affected in lesion of posterior column of spinal cord?

*Lesion in the posterior column of spinal cord and posterior nerve roots in syphilitic degenerative disease called tabes dorsalis *Characterised by impairment of proprioceptive sensibility,vibration,passive movement and appreciation of posture .patient become ataxic ,paicularly if he closes his eyes ,because he has lost his position sense for which he can paially compensate by visual knowledge of his spatial relationship(Romberg's sign) Ref Harrison20th edition pg 2766