Ulnar nerve palsy due to axillary crutch.

A young lady with residual polio, using axillary crutch since early childhood, presented with tingling, numbness and weakness in ulnar nerve distribution of five months duration. Ulnar motor conduction study revealed proximal conduction block near the axilla, at the point of pressure by the crutch while walking. Distal ulnar sensory conduction studies were normal but proximal ulnar sensory conduction studies showed absence of Erb's point potential. These findings suggested the presence of conduction block in sensory fibers as well. Proper use and change of axillary crutch resulted in clinical recovery and resolution of motor and sensory conduction block.