Can a nerve block on s1 cause foot drop?my gp and pysio think this is cause of my drop but consultant doesn't agree even though mri shows no causes?

Yes and No: Nerve block at s1 suggests that anesthetic and/or steroid were used to perform this. The anesthetic could result in foot weakness but typically that is weakness in pressing down with your foot which would result in persisted elevated foot. The foot drop/weakness would be only for length of anesthetic. If weakness does not resolve in by next day then consider eval and EMG testing of the nerves.

Unlikely: A single nerve block is unlikely to cause a foot drop. Check with neurologist, may need EMG or nerve conduction studies to help clarify the problem.