Stringhalt is a sudden flexion of one or both hind legs in the horse, most easily seen while the horse is walking or trotting.It is most evident when the horse is backing up slowly, turning on the affected leg, or suddenly frightened. It can involve one or both hind legs of the horse.ustralian stringhalt is differentiated from classical stringhalt by the severity, occurrence of outbreaks, distinct seasonal pattern and the ability of affected horses to recover spontaneously. This condition is characterised by the sudden exaggerated flexion of either one or both hocks.